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Junko Kyozuka

Section

Graduate School of Life Sciences

Job title

Specially Appointed Professor(Research)

Degree

農学博士（東京大学）

researchmap

https://researchmap.jp/JunkoKyozuka

J-GLOBAL ID

201601004961442574

Committee Memberships 29

植物化学調節学会　代議員

2024 - Present
日本植物学会　代議員

2024 - Present
日本植物生理学会　会長（代表理事）

2024 - Present
日本学術会議　連携会員

2023 - Present
基礎生物学研究所　外部評価委員

2021 - Present
Plant Physiology誌　エディター

2018 - Present
Journal of Genetics and Genomics 誌　エディター

2010 - Present
理化学研究所環境資源科学研究センター　アドバイザリー・カウンシル2014 CSRSAC2014委員

2024 - 2025
日本植物生理学会　年会委員長

2023 - 2024
日本植物生理学会　会長代理、代議員

2023 - 2024
日本植物生理学会　代議員

2016 - 2024
日本学術会議　会員

2020 - 2023
日本植物生理学会　常任理事

2021 - 2022
日本植物学会　代議員

2018 - 2022
岡山大学資源植物科学研究所　運営委員会委員

2016 - 2021
理化学研究所環境資源科学研究センター　アドバイザリー・カウンシル2019 CSRSAC2019委員

2019 - 2020
日本植物学会　理事

2019 - 2020
日本学術会議　会員

2017 - 2020
日本植物生理学会　常任理事

2018 - 2019
日本植物生理学会　学会賞選考委員

2015 - 2016
Plant Journal誌　エディター

2013 - 2016
独立行政法人農業生物資源研究所　評価助言会議委員

2011 - 2016
日本植物生理学会　評議員

2014 - 2015
日本植物生理学会　評議員

2010 - 2011
日本植物生理学会　常任評議員

2008 - 2009
日本植物生理学会　評議員

2002 - 2005
日本植物生理学会　庶務幹事

2001 - 2002
Plant and Cell Physiology 誌　編集委員
Plant Cell & Physiology誌　エディター

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Professional Memberships 5

植物化学調節学会

2018 - Present
日本学術会議24期、25期会員

2017/10 - Present
日本育種学会
植物学会
植物生理学会

Research Interests 3

Asexual reproduction
environment
Plant hormone

Research Areas 1

Life sciences / Plants: molecular biology and physiology /

Papers 113

snRNA-seq analysis of the moss Physcomitrium patens identifies a conserved cytokinin-ESR module promoting pluripotent stem cell identity Peer-reviewed

Yuki Hata, Nicola Hetherington, Kai Battenberg, Atsuko Hirota, Aki Minoda, Makoto Hayashi, Junko Kyozuka

Developmental Cell　2025/03
Publisher: Elsevier BV
DOI： 10.1016/j.devcel.2025.02.006 　

ISSN： 1534-5807
KAI2-dependent signaling controls vegetative reproduction in Marchantia polymorpha through activation of LOG-mediated cytokinin synthesis Peer-reviewed

Aino Komatsu, Mizuki Fujibayashi, Kazato Kumagai, Hidemasa Suzuki, Yuki Hata, Yumiko Takebayashi, Mikiko Kojima, Hitoshi Sakakibara, Junko Kyozuka

Nature Communications　16　(1)　2025/02/01
Publisher: Springer Science and Business Media LLC
DOI： 10.1038/s41467-024-55728-3 　

eISSN： 2041-1723
Conservation of symbiotic signaling since the most recent common ancestor of land plants Peer-reviewed

Tatiana Vernié, Mélanie Rich, Tifenn Pellen, Eve Teyssier, Vincent Garrigues, Lucie Chauderon, Lauréna Medioni, Fabian van Beveren, Cyril Libourel, Jean Keller, Camille Girou, Corinne Lefort, Aurélie Le Ru, Yves Martinez, Didier Reinhardt, Kyoichi Kodama, Shota Shimazaki, Patrice Morel, Junko Kyozuka, Malick Mbengue, Michiel Vandenbussche, Pierre-Marc Delaux

Proceedings of the National Academy of Sciences　122　(1)　2024/12/31
Publisher: Proceedings of the National Academy of Sciences
DOI： 10.1073/pnas.2408539121 　

ISSN： 0027-8424

eISSN： 1091-6490

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Plants have colonized lands 450 million years ago. This terrestrialization was facilitated by developmental and functional innovations. Recent evo-devo approaches have demonstrated that one of these innovations was the mutualistic arbuscular mycorrhizal symbiosis (AMS). The genetic pathways that have been involved in the establishment and functioning of AMS since its evolution remain poorly described. Here, we found that intracellular colonization by AM fungi induces a transcriptional reporter of the common symbiosis pathway, well-described in angiosperms, in the liverwort Marchantia paleacea . Mutants of either of the three main genes of this pathway, SYMRK , CCaMK, and CYCLOPS, disrupt the ability of M. paleacea to associate with AM fungi. Finally, overexpressing gain-of-function CCaMK or CYCLOPS leads to convergent transcriptomic signatures that partially overlap with AMS. Altogether, our data indicate that plants have maintained three genes of the common symbiotic pathway to support symbiotic interactions since their most recent common ancestor.
Contrasting and conserved roles of NPR pathways in diverged land plant lineages. International-journal Peer-reviewed

Hyung-Woo Jeon, Hidekazu Iwakawa, Satoshi Naramoto, Cornelia Herrfurth, Nora Gutsche, Titus Schlüter, Junko Kyozuka, Shingo Miyauchi, Ivo Feussner, Sabine Zachgo, Hirofumi Nakagami

The New phytologist　243　(6)　2295-2310　2024/09

DOI： 10.1111/nph.19981 　

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The NPR proteins function as salicylic acid (SA) receptors in Arabidopsis thaliana. AtNPR1 plays a central role in SA-induced transcriptional reprogramming whereby positively regulates SA-mediated defense. NPRs are found in the genomes of nearly all land plants. However, we know little about the molecular functions and physiological roles of NPRs in most plant species. We conducted phylogenetic and alignment analyses of NPRs from 68 species covering the significant lineages of land plants. To investigate NPR functions in bryophyte lineages, we generated and characterized NPR loss-of-function mutants in the liverwort Marchantia polymorpha. Brassicaceae NPR1-like proteins have characteristically gained or lost functional residues identified in AtNPRs, pointing to the possibility of a unique evolutionary trajectory for the Brassicaceae NPR1-like proteins. We find that the only NPR in M. polymorpha, MpNPR, is not the master regulator of SA-induced transcriptional reprogramming and negatively regulates bacterial resistance in this species. The Mpnpr transcriptome suggested roles of MpNPR in heat and far-red light responses. We identify both Mpnpr and Atnpr1-1 display enhanced thermomorphogenesis. Interspecies complementation analysis indicated that the molecular properties of AtNPR1 and MpNPR are partially conserved. We further show that MpNPR has SA-binding activity. NPRs and NPR-associated pathways have evolved distinctively in diverged land plant lineages to cope with different terrestrial environments.
Cytokinin and ALOG proteins regulate pluripotent stem cell identity in the moss Physcomitrium patens. International-journal Peer-reviewed

Yuki Hata, Juri Ohtsuka, Yuji Hiwatashi, Satoshi Naramoto, Junko Kyozuka

Science advances　10　(35)　eadq6082　2024/08/30

DOI： 10.1126/sciadv.adq6082 　

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The shoot apical meristem (SAM) contains pluripotent stem cells that produce all the aerial parts of the plant. Stem cells undergo asymmetric cell divisions to self-renew and to produce differentiating cells. Our research focused on unraveling the mechanisms governing the specification of these two distinct cell fates following the stem cell division. For this purpose, we used the model organism Physcomitrium patens, which features a singular pluripotent stem cell known as the gametophore apical cell. We show that the activity of cytokinins, critical stem cell regulators, is restricted to the gametophore apical cell due to the specific localization of PpLOG, the enzyme responsible for cytokinin activation. In turn, PpTAW, which promotes differentiating cell identity of the merophyte, is excluded from the gametophore apical cell by the action of cytokinins. We propose a cytokinin-based model for the establishment of asymmetry in the pluripotent stem cell division.
Δ4-dn-iso-OPDA, a bioactive plant hormone of Marchantia polymorpha Peer-reviewed

Takuya Kaji, Yuho Nishizato, Hidenori Yoshimatsu, Akiyoshi Yoda, Wenting Liang, Andrea Chini, Gemma Fernández-Barbero, Kei Nozawa, Junko Kyozuka, Roberto Solano, Minoru Ueda

iScience　27　(7)　110191-110191　2024/07
Publisher: Elsevier BV
DOI： 10.1016/j.isci.2024.110191 　

ISSN： 2589-0042
Unveiling the complexity of strigolactones: exploring structural diversity, biosynthesis pathways, and signaling mechanisms. International-journal Peer-reviewed

Takahito Nomura, Yoshiya Seto, Junko Kyozuka

Journal of experimental botany　75　(4)　1134-1147　2024/02/12

DOI： 10.1093/jxb/erad412 　

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Strigolactone is the collective name for compounds containing a butenolide as a part of their structure, first discovered as compounds that induce seed germination of root parasitic plants. They were later found to be rhizosphere signaling molecules that induce hyphal branching of arbuscular mycorrhizal fungi, and, finally, they emerged as a class of plant hormones. Strigolactones are found in root exudates, where they display a great variability in their chemical structure. Their structure varies among plant species, and multiple strigolactones can exist in one species. Over 30 strigolactones have been identified, yet the chemical structure of the strigolactone that functions as an endogenous hormone and is found in the above-ground parts of plants remains unknown. We discuss our current knowledge of the synthetic pathways of diverse strigolactones and their regulation, as well as recent progress in identifying strigolactones as plant hormones. Strigolactone is perceived by the DWARF14 (D14), receptor, an α/β hydrolase which originated by gene duplication of KARRIKIN INSENSITIVE 2 (KAI2). D14 and KAI2 signaling pathways are partially overlapping paralogous pathways. Progress in understanding the signaling mechanisms mediated by two α/β hydrolase receptors as well as remaining challenges in the field of strigolactone research are reviewed.
What's New in Strigolactone Research? Peer-reviewed

Shinjiro Yamaguchi, Yoshiya Seto, Junko Kyozuka

Plant & cell physiology　64　(9)　933-935　2023/09/15

DOI： 10.1093/pcp/pcad095 　
Activation of Strigolactone Biosynthesis by the DWARF14-LIKE/KARRIKIN-INSENSITIVE2 Pathway in Mycorrhizal Angiosperms, but Not in Arabidopsis, a Non-mycorrhizal Plant. Peer-reviewed

Kiyoshi Mashiguchi, Ryo Morita, Kai Tanaka, Kyoichi Kodama, Hiromu Kameoka, Junko Kyozuka, Yoshiya Seto, Shinjiro Yamaguchi

Plant & cell physiology　64　(9)　1066-1078　2023/09/15

DOI： 10.1093/pcp/pcad079 　

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Strigolactones (SLs) are a class of plant hormones that regulate many aspects of plant growth and development. SLs also improve symbiosis with arbuscular mycorrhizal fungi (AMF) in the rhizosphere. Recent studies have shown that the DWARF14-LIKE (D14L)/KARRIKIN-INSENSITIVE2 (KAI2) family, paralogs of the SL receptor D14, are required for AMF colonization in several flowering plants, including rice. In this study, we found that (-)-GR5, a 2'S-configured enantiomer of a synthetic SL analog (+)-GR5, significantly activated SL biosynthesis in rice roots via D14L. This result is consistent with a recent report, showing that the D14L pathway positively regulates SL biosynthesis in rice. In fact, the SL levels tended to be lower in the roots of the d14l mutant under both inorganic nutrient-deficient and -sufficient conditions. We also show that the increase in SL levels by (-)-GR5 was observed in other mycorrhizal plant species. In contrast, the KAI2 pathway did not upregulate the SL level and the expression of SL biosynthetic genes in Arabidopsis, a non-mycorrhizal plant. We also examined whether the KAI2 pathway enhances SL biosynthesis in the liverwort Marchantia paleacea, where SL functions as a rhizosphere signaling molecule for AMF. However, the SL level and SL biosynthetic genes were not positively regulated by the KAI2 pathway. These results imply that the activation of SL biosynthesis by the D14L/KAI2 pathway has been evolutionarily acquired after the divergence of bryophytes to efficiently promote symbiosis with AMF, although we cannot exclude the possibility that liverworts have specifically lost this regulatory system.
The transcriptional changes underlying the flowering phenology shift of Arabidopsis halleri in response to climate warming Peer-reviewed

Hideyuki Komoto, Ai Nagahama, Atsuko Miyawaki‐Kuwakado, Yuki Hata, Junko Kyozuka, Yui Kajita, Hironori Toyama, Akiko Satake

Plant, Cell & Environment　47　(1)　174-186　2023/09/10
Publisher: Wiley
DOI： 10.1111/pce.14716 　

ISSN： 0140-7791

eISSN： 1365-3040

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Abstract Climate warming is causing shifts in key life‐history events, including flowering time. To assess the impacts of increasing temperature on flowering phenology, it is crucial to understand the transcriptional changes of genes underlying the phenological shifts. Here, we conducted a comprehensive investigation of genes contributing to the flowering phenology shifts in response to increasing temperature by monitoring the seasonal expression dynamics of 293 flowering‐time genes along latitudinal gradients in the perennial herb, Arabidopsis halleri. Through transplant experiments at northern, southern and subtropical study sites in Japan, we demonstrated that the flowering period was shortened as latitude decreased, ultimately resulting in the loss of flowering opportunity in subtropical climates. The key transcriptional changes underlying the shortening of the flowering period and the loss of flowering opportunity were the diminished expression of floral pathway integrator genes and genes in the gibberellin synthesis and aging pathways, all of which are suppressed by increased expression of FLOWERING LOCUS C, a central repressor of flowering. These results suggest that the upper‐temperature limit of reproduction is governed by a relatively small number of genes that suppress reproduction in the absence of winter cold.
DIENELACTONE HYDROLASE LIKE PROTEIN1 negatively regulates the KAI2-ligand pathway in Marchantia polymorpha. International-journal Peer-reviewed

Hiromu Kameoka, Shota Shimazaki, Kiyoshi Mashiguchi, Bunta Watanabe, Aino Komatsu, Akiyoshi Yoda, Yohei Mizuno, Kyoichi Kodama, Masanori Okamoto, Takahito Nomura, Shinjiro Yamaguchi, Junko Kyozuka

Current biology : CB　2023/07/13

DOI： 10.1016/j.cub.2023.06.083 　

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Karrikins are smoke-derived butenolides that induce seed germination and photomorphogenesis in a wide range of plants.1,2,3 KARRIKIN INSENSITIVE2 (KAI2), a paralog of a strigolactone receptor, perceives karrikins or their metabolized products in Arabidopsis thaliana.4,5,6,7 Furthermore, KAI2 is thought to perceive an unidentified plant hormone, called KAI2 ligand (KL).8,9 KL signal is transduced via the interaction between KAI2, MORE AXILLARY GROWTH2 (MAX2), and SUPPRESSOR of MORE AXILLARY GROWTH2 1 LIKE family proteins (SMXLs), followed by the degradation of SMXLs.4,7,10,11,12,13,14 This signaling pathway is conserved both in A. thaliana and the bryophyte Marchantia polymorpha.14 Although the KL signaling pathway is well characterized, the KL metabolism pathways remain poorly understood. Here, we show that DIENELACTONE HYDROLASE LIKE PROTEIN1 (DLP1) is a negative regulator of the KL pathway in M. polymorpha. The KL signal induces DLP1 expression. DLP1 overexpression lines phenocopied the Mpkai2a and Mpmax2 mutants, while dlp1 mutants phenocopied the Mpsmxl mutants. Mutations in the KL signaling genes largely suppressed these phenotypes, indicating that DLP1 acts upstream of the KL signaling pathway, although DLP1 also has KL pathway-independent functions. DLP1 exhibited enzymatic activity toward a potential substrate, suggesting the possibility that DLP1 works through KL inactivation. Investigation of DLP1 homologs in A. thaliana revealed that they do not play a major role in the KL pathway, suggesting different mechanisms for the KL signal regulation. Our findings provide new insights into the regulation of the KL signal in M. polymorpha and the evolution of the KL pathway in land plants.
The D14 and KAI2 Orthologs of Gymnosperms Sense Strigolactones and KL Mimics, Respectively, and the Signals Are Transduced to Control Downstream Genes Peer-reviewed

Kyoichi Kodama, Xiaonan Xie, Junko Kyozuka

Plant And Cell Physiology　64　(9)　1057-1065　2023/07/03
Publisher: Oxford University Press (OUP)
DOI： 10.1093/pcp/pcad072 　

ISSN： 0032-0781

eISSN： 1471-9053

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Abstract Strigolactones (SLs), lactone-containing carotenoid derivatives, function as signaling molecules in the rhizosphere, inducing symbiosis with arbuscular mycorrhizal. In addition, as a class of plant hormones, SLs control plant growth and development in flowering plants (angiosperms). Recent studies show that the ancestral function of SLs, which precede terrestrialization of plants, is as rhizosphere signaling molecules. SLs were then recruited as a class of plant hormones through the step-by-step acquisition of signaling components. The D14 gene encoding the SL receptor arose by gene duplication of KARRIKIN INSENSITIVE2 (KAI2), the receptor of karrikins and KAI2 ligand (KL), an unknown ligand, in the common ancestor of seed plants. KL signaling targets SMAX1, a repressor protein. On the other hand, the SL signaling targets SMXL78 subclade repressors, which arose by duplication of SMAX1 in angiosperms. Thus, gymnosperms contain the SL receptor D14 but not SMXL78, the SL signaling–specific repressor proteins. We studied two gymnosperm species, ginkgo (Ginkgo biloba) and Japanese umbrella pine (Sciadopitys verticillata), to clarify whether SLs are perceived and the signals are transduced in gymnosperms. We show that D14 and KAI2 of ginkgo and Japanese umbrella pine specifically perceive an SL analog and KL mimic, respectively. Furthermore, our results suggest that both SL signaling and KL signaling target SMAX1, and the specific localization of the receptor may result in the specificity of the signaling in gymnosperms.
Zinc homeostasis governed by Golgi-resident ZnT family members regulates ERp44-mediated proteostasis at the ER-Golgi interface. International-journal Peer-reviewed

Yuta Amagai, Momo Yamada, Toshiyuki Kowada, Tomomi Watanabe, Yuyin Du, Rong Liu, Satoshi Naramoto, Satoshi Watanabe, Junko Kyozuka, Tiziana Anelli, Tiziana Tempio, Roberto Sitia, Shin Mizukami, Kenji Inaba

Nature communications　14　(1)　2683-2683　2023/05/09

DOI： 10.1038/s41467-023-38397-6 　

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Many secretory enzymes acquire essential zinc ions (Zn2+) in the Golgi complex. ERp44, a chaperone operating in the early secretory pathway, also binds Zn2+ to regulate its client binding and release for the control of protein traffic and homeostasis. Notably, three membrane transporter complexes, ZnT4, ZnT5/ZnT6 and ZnT7, import Zn2+ into the Golgi lumen in exchange with protons. To identify their specific roles, we here perform quantitative Zn2+ imaging using super-resolution microscopy and Zn2+-probes targeted in specific Golgi subregions. Systematic ZnT-knockdowns reveal that ZnT4, ZnT5/ZnT6 and ZnT7 regulate labile Zn2+ concentration at the distal, medial, and proximal Golgi, respectively, consistent with their localization. Time-course imaging of cells undergoing synchronized secretory protein traffic and functional assays demonstrates that ZnT-mediated Zn2+ fluxes tune the localization, trafficking, and client-retrieval activity of ERp44. Altogether, this study provides deep mechanistic insights into how ZnTs control Zn2+ homeostasis and ERp44-mediated proteostasis along the early secretory pathway.
Environmental control of rice flowering time Peer-reviewed

Giulio Vicentini, Marco Biancucci, Lorenzo Mineri, Daniele Chirivì, Francesca Giaume, Yiling Miao, Junko Kyozuka, Vittoria Brambilla, Camilla Betti, Fabio Fornara

Plant Communications　100610-100610　2023/05/04
Publisher: Elsevier BV
DOI： 10.1016/j.xplc.2023.100610 　

ISSN： 2590-3462
Control of vegetative reproduction in Marchantiapolymorpha by the KAI2-ligand signaling pathway. International-journal Peer-reviewed

Aino Komatsu, Kyoichi Kodama, Yohei Mizuno, Mizuki Fujibayashi, Satoshi Naramoto, Junko Kyozuka

Current biology : CB　2023/04/10

DOI： 10.1016/j.cub.2023.02.022 　

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In vegetative reproduction of Marchantia polymorpha (M. polymorpha), propagules, called gemmae, are formed in gemma cups. Despite its significance for survival, control of gemma and gemma cup formation by environmental cues is not well understood. We show here that the number of gemmae formed in a gemma cup is a genetic trait. Gemma formation starts from the central region of the floor of the gemma cup, proceeds to the periphery, and terminates when the appropriate number of gemmae is initiated. The MpKARRIKIN INSENSITIVE2 (MpKAI2)-dependent signaling pathway promotes gemma cup formation and gemma initiation. The number of gemmae in a cup is controlled by modulating the ON/OFF switch of the KAI2-dependent signaling. Termination of the signaling results in the accumulation of MpSMXL, a suppressor protein. In the Mpsmxl mutants, gemma initiation continues, leading to the formation of a highly increased number of gemmae in a cup. Consistent with its function, the MpKAI2-dependent signaling pathway is active in gemma cups where gemmae initiate, as well as in the notch region of the mature gemma and midrib of the ventral side of the thallus. In this work, we also show that GEMMA CUP-ASSOCIATED MYB1 works downstream of this signaling pathway to promote gemma cup formation and gemma initiation. We also found that the availability of potassium affects gemma cup formation independently from the KAI2-dependent signaling pathway in M. polymorpha. We propose that the KAI2-dependent signaling pathway functions to optimize vegetative reproduction by adapting to the environment in M. polymorpha.
Two florigens and a florigen-like protein form a triple regulatory module at the shoot apical meristem to promote reproductive transitions in rice Peer-reviewed

Francesca Giaume, Giulia Ave Bono, Damiano Martignago, Yiling Miao, Giulio Vicentini, Taiyo Toriba, Rui Wang, Dali Kong, Martina Cerise, Daniele Chirivì, Marco Biancucci, Bahman Khahani, Piero Morandini, Wladimir Tameling, Michela Martinotti, Daniela Goretti, George Coupland, Martin Kater, Vittoria Brambilla, Daisuke Miki, Junko Kyozuka, Fabio Fornara

Nature Plants　9　(4)　525-534　2023/03/27

DOI： 10.1038/s41477-023-01383-3 　

ISSN： 2055-026X

eISSN： 2055-0278
Precise and heritable gene targeting in rice using a sequential transformation strategy Peer-reviewed

Wenxin Zhang, Rui Wang, Dali Kong, Fangnan Peng, Mei Chen, Wenjie Zeng, Francesca Giaume, Sheng He, Hui Zhang, Zhen Wang, Junko Kyozuka, Jian-Kang Zhu, Fabio Fornara, Daisuke Miki

Cell Reports Methods　3　(1)　100389-100389　2023/01/23
Publisher: Elsevier BV
DOI： 10.1016/j.crmeth.2022.100389 　

ISSN： 2667-2375
An Ancestral Function of Strigolactones as Symbiotic Rhizosphere Signals Peer-reviewed

Kyoichi Kodama, Mélanie K. Rich, Akiyoshi Yoda, Shota Shimazaki, Xiaonan Xie, Kohki Akiyama, Yohei Mizuno, Aino Komatsu, Yi Luo, Hidemasa Suzuki, Hiromu Kameoka, Cyril Libourel, Jean Keller, Keiko Sakakibara, Tomoaki Nishiyama, Tomomi Nakagawa, Kiyoshi Mashiguchi, Kenichi Uchida, Kaori Yoneyama, Yoshikazu Tanaka, Shinjiro Yamaguchi, Masaki Shimamura, Pierre-Marc Delaux, Takahito Nomura, Junko Kyozuka

Nature communications　13　(1)　3974　2022/07/08
Publisher: Cold Spring Harbor Laboratory
DOI： 10.1101/2021.08.20.457034 　

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Abstract In flowering plants, carotenoid-derived strigolactones (SLs) have dual functions as hormones that regulate growth and development, and as rhizosphere signaling molecules that induce symbiosis with arbuscular mycorrhizal (AM) fungi. Here, we report the identification of bryosymbiol (BSB), a previously unidentified SL from the bryophyte Marchantia paleacea. BSB is also found in vascular plants, indicating that it is ancestral in land plants. BSB synthesis is enhanced at AM symbiosis permissive conditions and BSB deficient mutants are impaired in AM symbiosis. In contrast, the absence of BSB synthesis has little effect on the growth and gene expression. We show that the introduction of the SL receptor of Arabidopsis renders M. paleacea cells BSB-responsive. These results suggest that BSB is not perceived by M. paleacea cells due to the lack of cognate SL receptors. We propose that SLs originated as AM symbiosis-inducing rhizosphere signaling molecules and were later recruited as plant hormone.
ABERRANT PANICLE ORGANIZATION2 controls multiple steps in panicle formation through common direct-target genes Peer-reviewed

Yiling Miao, Qian Xun, Teruaki Taji, Keisuke Tanaka, Naoko Yasuno, Chengqiang Ding, Junko Kyozuka

Plant Physiology　189　(4)　2210-2226　2022/05/13
Publisher: Oxford University Press (OUP)
DOI： 10.1093/plphys/kiac216 　

ISSN： 0032-0889

eISSN： 1532-2548

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Abstract At the transition from vegetative to reproductive growth in rice (Oryza sativa), a developmental program change occurs, resulting in panicle (rice inflorescence) formation. The initial event of the transition is the change of the shoot apical meristem to an inflorescence meristem (IM), accompanied by a rapid increase in the meristem size. Suppression of leaf growth also occurs, resulting in the formation of bracts. The IM generates branch meristems (BMs), indeterminate meristems that reiteratively generate next-order meristems. All meristems eventually acquire a determinate spikelet meristem identity and terminate after producing a floret. ABERRANT PANICLE ORGANIZATION2 (APO2) is the rice ortholog of Arabidopsis (Arabidopsis thaliana) LEAFY (LFY), a plant-specific transcription factor (TF). APO2 is a positive regulator of panicle branch formation. Here, we show that APO2 is also required to increase the meristem size of the IM and suppress bract outgrowth. We identified genes directly and indirectly regulated by APO2 and identified APO2-binding sites. These analyses showed that APO2 directly controls known regulators of panicle development, including SQUAMOSA PROMOTER BINDING PROTEIN LIKE14 and NECK LEAF1. Furthermore, we revealed that a set of genes act as downstream regulators of APO2 in controlling meristem cell proliferation during reproductive transition, bract suppression, and panicle branch formation. Our findings indicate that APO2 acts as a master regulator of rice panicle development by regulating multiple steps in the reproductive transition through directly controlling a set of genes.
NARROW AND DWARF LEAF 1, the Ortholog of Arabidopsis ENHANCER OF SHOOT REGENERATION1/DORNRÖSCHEN, Mediates Leaf Development and Maintenance of the Shoot Apical Meristem in Oryza sativa L Peer-reviewed

Andree S Kusnandar, Jun-Ichi Itoh, Yutaka Sato, Eriko Honda, Ken-ichiro Hibara, Junko Kyozuka, Satoshi Naramoto

Plant and Cell Physiology　63　(2)　265-278　2022/02/15
Publisher: Oxford University Press (OUP)
DOI： 10.1093/pcp/pcab169 　

ISSN： 0032-0781

eISSN： 1471-9053

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Abstract The molecular basis for leaf development, a major focus in developmental biology, remains unclear in the monocotyledonous grass, rice (Oryza sativa). Here, we performed a mutant screen in rice and identified an AP2-type transcription factor family protein, NARROW AND DWARF LEAF1 (NDL1). NDL1 is the ortholog of Arabidopsis thaliana (subsequently called Arabidopsis) ENHANCER OF SHOOT REGENERATION1 (ESR1)/DORNRÖSCHEN (DRN) and mediates leaf development and maintenance of the shoot apical meristem (SAM). Loss of function of NDL1 results in bladeless leaves and SAMs that are flat, rather than dome-shaped, and lack cell proliferation activity. This loss of function also causes reduced auxin signaling. Moreover, as is the case with Arabidopsis ESR1/DRN, NDL1 plays crucial roles in shoot regeneration. Importantly, we found that NDL1 is not expressed in the SAM but is expressed in leaf primordia. We propose that NDL1 cell autonomously regulates leaf development, but non-cell autonomously regulates SAM maintenance in rice.
Origins and evolution of the dual functions of strigolactones as rhizosphere signaling molecules and plant hormones. International-journal Peer-reviewed

Junko Kyozuka, Takahito Nomura, Masaki Shimamura

Current opinion in plant biology　65　102154-102154　2022/02

DOI： 10.1016/j.pbi.2021.102154 　

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Strigolactones (SLs) play roles as a class of plant hormones and rhizosphere signaling chemicals that induce hyphal branching of arbuscular mycorrhizal fungi and seed germination of parasitic plants. Therefore, SLs have dual functions. Recent progress in genome sequencing and genetic studies of bryophytes and algae has begun to shed light on the origin and evolution of these two functions of SLs.
The bryophytes Physcomitrium patens and Marchantia polymorpha as model systems for studying evolutionary cell and developmental biology in plants. International-journal Peer-reviewed

Satoshi Naramoto, Yuki Hata, Tomomichi Fujita, Junko Kyozuka

The Plant cell　34　(1)　228-246　2021/08/30

DOI： 10.1093/plcell/koab218 　

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Bryophytes are non-vascular spore-forming plants. Unlike in flowering plants, the gametophyte (haploid) generation of bryophytes dominates the sporophyte (diploid) generation. A comparison of bryophytes with flowering plants allows us to answer some fundamental questions raised in evolutionary cell and developmental biology. The moss Physcomitrium patens was the first bryophyte with a sequenced genome. Many cell and developmental studies have been conducted in this species using gene targeting by homologous recombination. The liverwort Marchantia polymorpha has recently emerged as an excellent model system with low genomic redundancy in most of its regulatory pathways. With the development of molecular genetic tools such as efficient genome editing, both P. patens and M. polymorpha have provided many valuable insights. Here, we review these advances, with a special focus on polarity formation at the cell and tissue levels. We examine current knowledge regarding the cellular mechanisms of polarized cell elongation and cell division, including symmetric and asymmetric cell division. We also examine the role of polar auxin transport in mosses and liverworts. Finally, we discuss the future of evolutionary cell and developmental biological studies in plants.
Lipid exchanges drove the evolution of mutualism during plant terrestrialization Peer-reviewed

Mélanie K. Rich, Nicolas Vigneron, Cyril Libourel, Jean Keller, Li Xue, Mohsen Hajheidari, Guru V. Radhakrishnan, Aurélie Le Ru, Seydina Issa Diop, Giacomo Potente, Elena Conti, Danny Duijsings, Aurélie Batut, Pauline Le Faouder, Kyoichi Kodama, Junko Kyozuka, Erika Sallet, Guillaume Bécard, Marta Rodriguez-Franco, Thomas Ott, Justine Bertrand-Michel, Giles E. D. Oldroyd, Péter Szövényi, Marcel Bucher, Pierre-Marc Delaux

Science　372　(6544)　864-868　2021/05/21
Publisher: American Association for the Advancement of Science (AAAS)
DOI： 10.1126/science.abg0929 　

ISSN： 0036-8075

eISSN： 1095-9203

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Symbiosis with arbuscular mycorrhizal fungi (AMF) improves plant nutrition in most land plants, and its contribution to the colonization of land by plants has been hypothesized. Here, we identify a conserved transcriptomic response to AMF among land plants, including the activation of lipid metabolism. Using gain of function, we show the transfer of lipids from the liverwort <italic>Marchantia paleacea</italic> to AMF and its direct regulation by the transcription factor WRINKLED (WRI). Arbuscules, the nutrient-exchange structures, were not formed in loss-of-function <italic>wri</italic> mutants in <italic>M. paleacea</italic>, leading to aborted mutualism. Our results show the orthology of the symbiotic transfer of lipids across land plants and demonstrate that mutualism with arbuscular mycorrhizal fungi was present in the most recent ancestor of land plants 450 million years ago.
Major components of the KARRIKIN INSENSITIVE2-dependent signaling pathway are conserved in the liverwort Marchantia polymorpha International-journal Peer-reviewed

Yohei Mizuno, Aino Komatsu, Shota Shimazaki, Satoshi Naramoto, Keisuke Inoue, Xiaonan Xie, Kimitsune Ishizaki, Takayuki Kohchi, Junko Kyozuka

The Plant Cell　33　(7)　2395-2411　2021/04/11
Publisher: Oxford University Press (OUP)
DOI： 10.1093/plcell/koab106 　

eISSN： 1532-298X

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<title>Abstract</title> KARRIKIN INSENSITIVE2 (KAI2) was first identified as a receptor of karrikins, smoke-derived germination stimulants. KAI2 is also considered a receptor of an unidentified endogenous molecule called the KAI2-ligand (KL). Upon KAI2 activation, signals are transmitted through degradation of D53/SMXL proteins via MAX2-dependent ubiquitination. Although components in the KAI2-dependent signaling pathway, namely MpKAI2A and MpKAI2B, MpMAX2, and MpSMXL, exist in the genome of the liverwort Marchantia polymorpha, their functions remain unknown. Here, we show that early thallus growth is retarded and gemma dormancy in the dark is suppressed in Mpkai2a and Mpmax2 loss-of-function mutants. These defects are counteracted in Mpkai2a Mpsmxl and Mpmax2 Mpsmxl double mutants indicating that MpKAI2A, MpMAX2 and MpSMXL act in the same genetic pathway. Introduction of MpSMXLd53, in which a domain required for degradation is mutated, into wild-type plants mimicks Mpkai2a and Mpmax2 plants. In addition, detection of citrine fluorescence in Nicotiana benthamiana cells transiently expressing a SMXL-Citrine fusion protein requires treatment with MG132, a proteasome inhibitor. These findings imply that MpSMXL is subjected to degradation, and that degradation of MpSMXL is crucial for MpKAI2A-dependent signaling in M. polymorpha. Therefore, we claim that the basic mechanisms in the KAI2-dependent signaling pathway are conserved in M. polymorpha.
Fundamental mechanisms of the stem cell regulation in land plants: lesson from shoot apical cells in bryophytes Peer-reviewed

Yuki Hata, Junko Kyozuka

Plant Molecular Biology　2021/02/20
Publisher: Springer Science and Business Media LLC
DOI： 10.1007/s11103-021-01126-y 　

ISSN： 0167-4412

eISSN： 1573-5028
Plant stem cell research is uncovering the secrets of longevity and persistent growth Peer-reviewed

Masaaki Umeda, Momoko Ikeuchi, Masaki Ishikawa, Toshiro Ito, Ryuichi Nishihama, Junko Kyozuka, Keiko U. Torii, Akiko Satake, Gohta Goshima, Hitoshi Sakakibara

The Plant Journal　106　(2)　326-335　2021/02/03

DOI： 10.1111/tpj.15184 　

ISSN： 0960-7412

eISSN： 1365-313X
Desmethyl butenolides are optimal ligands for karrikin receptor proteins Peer-reviewed

Jiaren Yao, Adrian Scaffidi, Yongjie Meng, Kim T Melville, Aino Komatsu, Aashima Khosla, David C Nelson, Junko Kyozuka, Gavin R Flematti, Mark T Waters

New Phytologist　230　(3)　1003-1016　2021/01/21
Publisher: Wiley
DOI： 10.1111/nph.17224 　

ISSN： 0028-646X

eISSN： 1469-8137
The origin and evolution of the ALOG proteins, members of a plant-specific transcription factor family, in land plants. Invited Peer-reviewed

Satoshi Naramoto, Yuki Hata, Junko Kyozuka

Journal of plant research　133　(3)　323-329　2020/05

DOI： 10.1007/s10265-020-01171-6 　

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The Arabidopsis LSH1 and Oryza G1 (ALOG) protein is a family of plant-specific transcription factors that regulate reproductive growth in angiosperms. Despite their importance in plant development, little research has been conducted on ALOG proteins in basal land plants and the processes involved in their evolution remain largely unknown. Here, we studied the molecular evolution of ALOG family proteins. We found that ALOG proteins are absent in green algae but exist in all land plants analyzed as well as in some Charophycean algae, closest relatives of land plants. Multiple sequence alignments identified the high sequence conservation of ALOG domains in divergent plant lineages. Phylogenetic analyses also identified a distinct clade of ALOG protein member of lycophytes and bryophytes, including two of Marchantia polymorpha LATERAL ORGAN SUPPRESOR (MpLOS1 and MpLOS2) with a long branch length in MpLOS2. Consistent with this, the function of MpLOS1 was replaceable by Phycomitrella patens ALOG proteins, whereas MpLOS2 failed to replace the molecular function of MpLOS1. Moreover, the rice ALOG proteins, OsTAW1 and OsG1, were not able to replace the molecular function of MpLOS1 although we previously found that the function of OsG1 was replaceable by MpLOS1. Altogether, these findings suggest that ALOG proteins emerged before the evolution of land plants and that they exhibit functional conservation and diversification during the evolution of land plants. The finding that MpLOS1 is able to complement rice ALOG mutants but not vice versa also suggest the existence of conserved and the partly divergent functions of ALOG proteins in bryophytes and angiosperms.
Suppression of Leaf Blade Development by BLADE-ON-PETIOLE Orthologs Is a Common Strategy for Underground Rhizome Growth. International-journal Peer-reviewed

Taiyo Toriba, Hiroki Tokunaga, Kazuma Nagasawa, Fanyu Nie, Akiko Yoshida, Junko Kyozuka

Current biology : CB　30　(3)　509-516　2020/02/03

DOI： 10.1016/j.cub.2019.11.055 　

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Rhizomes are modified stems that grow horizontally underground in various perennial species, a growth habit that is advantageous for vigorous asexual proliferation. In Oryza longistaminata, a rhizomatous wild relative of cultivated rice (Oryza sativa), leaves in the aerial shoots consist of a distal leaf blade and a proximal leaf sheath [1]. Leaf blade formation is, however, suppressed in rhizome leaves. In O. sativa, BLADE-ON-PETIOLE (BOP) genes are the main regulators of proximal-distal leaf patterning [2]. During the juvenile phase of O. sativa, BOP expression is maintained at high levels by the small regulatory RNA microRNA156 (miR156), leading to formation of leaves consisting predominantly of the sheath. Here, we show that in O. longistaminata, high expression of BOPs caused by miR156 was responsible for suppression of the blade in rhizomes and that bop loss-of-function mutants produced leaves consisting of the leaf blade only. Rhizome growth in soil was also hampered in the mutants due to a severe reduction in rhizome tip stiffness. Leaf blade formation is also suppressed in the stolons of Zoysia matrella, a monocot species, and in the rhizomes of Houttuynia cordata, a dicot species, indicating that leaf blade suppression is widely conserved. We also show that strong expression of BOP homologs in both rhizome and stolon leaves rather than in aerial leaves is another conserved feature. We propose that suppression of the leaf blade by BOP is an evolutionary strategy that has been commonly recruited by both rhizomatous and stoloniferous species to establish their unique growth habit.
A conserved regulatory mechanism mediates the convergent evolution of plant shoot lateral organs. International-journal Peer-reviewed

Satoshi Naramoto, Victor Arnold Shivas Jones, Nicola Trozzi, Mayuko Sato, Kiminori Toyooka, Masaki Shimamura, Sakiko Ishida, Kazuhiko Nishitani, Kimitsune Ishizaki, Ryuichi Nishihama, Takayuki Kohchi, Liam Dolan, Junko Kyozuka

PLoS biology　17　(12)　e3000560　2019/12

DOI： 10.1371/journal.pbio.3000560 　

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Land plant shoot structures evolved a diversity of lateral organs as morphological adaptations to the terrestrial environment, with lateral organs arising independently in different lineages. Vascular plants and bryophytes (basally diverging land plants) develop lateral organs from meristems of sporophytes and gametophytes, respectively. Understanding the mechanisms of lateral organ development among divergent plant lineages is crucial for understanding the evolutionary process of morphological diversification of land plants. However, our current knowledge of lateral organ differentiation mechanisms comes almost entirely from studies of seed plants, and thus, it remains unclear how these lateral structures evolved and whether common regulatory mechanisms control the development of analogous lateral organs. Here, we performed a mutant screen in the liverwort Marchantia polymorpha, a bryophyte, which produces gametophyte axes with nonphotosynthetic scalelike lateral organs. We found that an Arabidopsis LIGHT-DEPENDENT SHORT HYPOCOTYLS 1 and Oryza G1 (ALOG) family protein, named M. polymorpha LATERAL ORGAN SUPRESSOR 1 (MpLOS1), regulates meristem maintenance and lateral organ development in Marchantia. A mutation in MpLOS1, preferentially expressed in lateral organs, induces lateral organs with misspecified identity and increased cell number and, furthermore, causes defects in apical meristem maintenance. Remarkably, MpLOS1 expression rescued the elongated spikelet phenotype of a MpLOS1 homolog in rice. This suggests that ALOG genes regulate the development of lateral organs in both gametophyte and sporophyte shoots by repressing cell divisions. We propose that the recruitment of ALOG-mediated growth repression was in part responsible for the convergent evolution of independently evolved lateral organs among highly divergent plant lineages, contributing to the morphological diversification of land plants.
BLADE-ON-PETIOLE genes are not involved in the transition from protonema to gametophore in the moss Physcomitrella patens. Peer-reviewed

Yuki Hata, Satoshi Naramoto, Junko Kyozuka

Journal of plant research　132　(5)　617-627　2019/09

DOI： 10.1007/s10265-019-01132-8 　

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The timing of the transition between developmental phases is a critical determinant of plant form. In the moss Physcomitrella patens, the transition from protonema to gametophore is a particularly important step as it results in a change from two-dimensional to three-dimensional growth of the plant body. It is well known that this transition is promoted by cytokinin (CK), however, the underlying mechanisms are poorly understood. Previously, it was reported that P. patens orthologs of BLADE-ON-PETIOLE (BOP) genes (PpBOPs) work downstream of CK to promote the transition to gametophore. To further understand the role of PpBOPs in the control of this transition, we performed functional analyses of PpBOP genes. We simultaneously disrupted the function of all three PpBOP genes in P. patens using CRISPR technology, however, no abnormal phenotypes were observed in the triple mutant during either the gametophytic or the sporophytic growth stages. CK treatment did not alter the phase change in the triple mutant. We conclude that PpBOP genes are unnecessary in the control of P. patens development under normal conditions. We propose that BOP genes are not involved in the control of developmental processes in bryophytes and other basal land plants, but may function in physiological processes such as in the defense response.
Cytokinin Signaling Is Essential for Organ Formation in Marchantia polymorpha. Peer-reviewed

Shiori S Aki, Tatsuya Mikami, Satoshi Naramoto, Ryuichi Nishihama, Kimitsune Ishizaki, Mikiko Kojima, Yumiko Takebayashi, Hitoshi Sakakibara, Junko Kyozuka, Takayuki Kohchi, Masaaki Umeda

Plant & cell physiology　60　(8)　1842-1854　2019/08/01

DOI： 10.1093/pcp/pcz100 　

ISSN： 0032-0781

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Cytokinins are known to regulate various physiological events in plants. Cytokinin signaling is mediated by the phosphorelay system, one of the most ancient mechanisms controlling hormonal pathways in plants. The liverwort Marchantia polymorpha possesses all components necessary for cytokinin signaling; however, whether they respond to cytokinins and how the signaling is fine-tuned remain largely unknown. Here, we report cytokinin function in Marchantia development and organ formation. Our measurement of cytokinin species revealed that cis-zeatin is the most abundant cytokinin in Marchantia. We reduced the endogenous cytokinin level by overexpressing the gene for cytokinin oxidase, MpCKX, which inactivates cytokinins, and generated overexpression and knockout lines for type-A (MpRRA) and type-B (MpRRB) response regulators to manipulate the signaling. The overexpression lines of MpCKX and MpRRA, and the knockout lines of MpRRB, shared phenotypes such as inhibition of gemma cup formation, enhanced rhizoid formation and hyponastic thallus growth. Conversely, the knockout lines of MpRRA produced more gemma cups and exhibited epinastic thallus growth. MpRRA expression was elevated by cytokinin treatment and reduced by knocking out MpRRB, suggesting that MpRRA is upregulated by the MpRRB-mediated cytokinin signaling, which is antagonized by MpRRA. Our findings indicate that when plants moved onto land they already deployed the negative feedback loop of cytokinin signaling, which has an indispensable role in organogenesis.
Developmental analysis of the early steps in strigolactone‐mediated axillary bud dormancy in rice International-journal Peer-reviewed

Le Luo, Megumu Takahashi, Hiromu Kameoka, Ruyi Qin, Toshihide Shiga, Yuri Kanno, Mitsunori Seo, Masaki Ito, Guohua Xu, Junko Kyozuka

The Plant journal : for cell and molecular biology　97　(6)　1006-1021　2019/03

DOI： 10.1111/tpj.14266 　

ISSN： 0960-7412

eISSN： 1365-313X
BLADE-ON-PETIOLE genes temporally and developmentally regulate the sheath to blade ratio of rice leaves. International-journal Peer-reviewed

Taiyo Toriba, Hiroki Tokunaga, Toshihide Shiga, Fanyu Nie, Satoshi Naramoto, Eriko Honda, Keisuke Tanaka, Teruaki Taji, Jun-Ichi Itoh, Junko Kyozuka

Nature communications　10　(1)　619-619　2019/02/06

DOI： 10.1038/s41467-019-08479-5 　

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Axis formation is a fundamental issue in developmental biology. Axis formation and patterning in plant leaves is crucial for morphology and crop productivity. Here, we reveal the basis of proximal-distal patterning in rice leaves, which consist of a proximal sheath, a distal blade, and boundary organs formed between these two regions. Analysis of the three rice homologs of the Arabidopsis BLADE-ON-PETIOLE1 (BOP1) gene indicates that OsBOPs activate proximal sheath differentiation and suppress distal blade differentiation. Temporal expression changes of OsBOPs are responsible for the developmental changes in the sheath:blade ratio. We further identify that the change in the sheath:blade ratio during the juvenile phase is controlled by the miR156/SPL pathway, which modifies the level and pattern of expression of OsBOPs. OsBOPs are also essential for differentiation of the boundary organs. We propose that OsBOPs, the main regulators of proximal-distal patterning, control temporal changes in the sheath:blade ratio of rice leaves.
Strigolactone perception and deactivation by a hydrolase receptor DWARF14. International-journal Peer-reviewed

Yoshiya Seto, Rei Yasui, Hiromu Kameoka, Muluneh Tamiru, Mengmeng Cao, Ryohei Terauchi, Akane Sakurada, Rena Hirano, Takaya Kisugi, Atsushi Hanada, Mikihisa Umehara, Eunjoo Seo, Kohki Akiyama, Jason Burke, Noriko Takeda-Kamiya, Weiqiang Li, Yoshinori Hirano, Toshio Hakoshima, Kiyoshi Mashiguchi, Joseph P Noel, Junko Kyozuka, Shinjiro Yamaguchi

Nature communications　10　(1)　191-191　2019/01/14

DOI： 10.1038/s41467-018-08124-7 　

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The perception mechanism for the strigolactone (SL) class of plant hormones has been a subject of debate because their receptor, DWARF14 (D14), is an α/β-hydrolase that can cleave SLs. Here we show via time-course analyses of SL binding and hydrolysis by Arabidopsis thaliana D14, that the level of uncleaved SL strongly correlates with the induction of the active signaling state. In addition, we show that an AtD14D218A catalytic mutant that lacks enzymatic activity is still able to complement the atd14 mutant phenotype in an SL-dependent manner. We conclude that the intact SL molecules trigger the D14 active signaling state, and we also describe that D14 deactivates bioactive SLs by the hydrolytic degradation after signal transmission. Together, these results reveal that D14 is a dual-functional receptor, responsible for both the perception and deactivation of bioactive SLs.
Comprehensive panicle phenotyping reveals that qSrn7/FZP influences higher-order branching. International-journal Peer-reviewed

Yasuko Fujishiro, Ayumi Agata, Sadayuki Ota, Ryota Ishihara, Yasumi Takeda, Takeshi Kunishima, Mayuko Ikeda, Junko Kyozuka, Tokunori Hobo, Hidemi Kitano

Scientific reports　8　(1)　12511-12511　2018/08/21

DOI： 10.1038/s41598-018-30395-9 　

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Rice grain number directly affects crop yield. Identifying alleles that improve panicle architecture would greatly aid the development of high-yield varieties. Here, we show that the quantitative trait locus qSrn7 contains rice FRIZZY PANICLE (FZP), a previously reported gene encoding an ERF transcription factor that promotes floral transition. Reduced expression of FZP in the reproductive stage increases the extent of higher order branching of the panicle, resulting in increased grain number. Genotype analysis of this gene in cultivars from the publicly available National Institute of Agrobiological Sciences (NIAS) Core Collection demonstrated that the extent of higher order branching, especially in the upper panicle, was increased in those cultivars carrying the FZP allele associated with qSrn7. Furthermore, chromosome segment substitution lines resulting from a cross between Koshihikari and Kasalath, the latter of which carries qSrn7/FZP, also showed that upper panicle higher order branching and grain yield were increased by qSrn7/FZP. Our findings indicate that qSrn7/FZP influences panicle branching pattern and is thus useful in the breeding of high-yield rice varieties.
ARF GTPase machinery at the plasma membrane regulates auxin transport-mediated plant growth. Invited Peer-reviewed

Satoshi Naramoto, Junko Kyozuka

Plant biotechnology (Tokyo, Japan)　35　(2)　155-159　2018/06/25

DOI： 10.5511/plantbiotechnology.18.0312a 　

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VAN3 is a plant ACAP-type ADP-ribosylation factor-GTPase activating protein (ARF-GAP) that regulates auxin transport-mediated plant morphogenesis such as continuous venation and lateral root development in Arabidopsis. Previous studies suggested that VAN3 localizes at the plasma membrane (PM) and intracellular structures. However, the role of PM localization in mediating the van3 mutant phenotype is not clear. Here we performed subcellular localization analysis of VAN3 and its regulators CVP2 and VAB to determine their endogenous functions. We found that GFP-tagged CVP2 and VAB preferentially localize at the PM in stably transformed plants. We determined that transgenic plants with lower expression levels of GFP- or mRFP-tagged VAN3 displayed PM localization, which was sufficient to rescue the van3 mutant. Functional VAN3-mRFP and VAB-GFP colocalized at PMs. The van3 mutant phenotype was suppressed by mutation of VAN7/GNOM, which encodes an ARF-GEF that localizes at the PM and Golgi apparatus. These combined results suggest that ARF-GTPase machinery at the PM regulates auxin transport-mediated plant growth and development.
Strigolactone Biosynthesis Genes of Rice are Required for the Punctual Entry of Arbuscular Mycorrhizal Fungi into the Roots. Peer-reviewed

Yoshihiro Kobae, Hiromu Kameoka, Yusaku Sugimura, Katsuharu Saito, Ryo Ohtomo, Toru Fujiwara, Junko Kyozuka

Plant & cell physiology　59　(3)　544-553　2018/03/01

DOI： 10.1093/pcp/pcy001 　

ISSN： 0032-0781
Insights into Land Plant Evolution Garnered from the Marchantia polymorpha Genome. International-journal Peer-reviewed

John L Bowman, Takayuki Kohchi, Katsuyuki T Yamato, Jerry Jenkins, Shengqiang Shu, Kimitsune Ishizaki, Shohei Yamaoka, Ryuichi Nishihama, Yasukazu Nakamura, Frédéric Berger, Catherine Adam, Shiori Sugamata Aki, Felix Althoff, Takashi Araki, Mario A Arteaga-Vazquez, Sureshkumar Balasubrmanian, Kerrie Barry, Diane Bauer, Christian R Boehm, Liam Briginshaw, Juan Caballero-Perez, Bruno Catarino, Feng Chen, Shota Chiyoda, Mansi Chovatia, Kevin M Davies, Mihails Delmans, Taku Demura, Tom Dierschke, Liam Dolan, Ana E Dorantes-Acosta, D Magnus Eklund, Stevie N Florent, Eduardo Flores-Sandoval, Asao Fujiyama, Hideya Fukuzawa, Bence Galik, Daniel Grimanelli, Jane Grimwood, Ueli Grossniklaus, Takahiro Hamada, Jim Haseloff, Alexander J Hetherington, Asuka Higo, Yuki Hirakawa, Hope N Hundley, Yoko Ikeda, Keisuke Inoue, Shin-Ichiro Inoue, Sakiko Ishida, Qidong Jia, Mitsuru Kakita, Takehiko Kanazawa, Yosuke Kawai, Tomokazu Kawashima, Megan Kennedy, Keita Kinose, Toshinori Kinoshita, Yuji Kohara, Eri Koide, Kenji Komatsu, Sarah Kopischke, Minoru Kubo, Junko Kyozuka, Ulf Lagercrantz, Shih-Shun Lin, Erika Lindquist, Anna M Lipzen, Chia-Wei Lu, Efraín De Luna, Robert A Martienssen, Naoki Minamino, Masaharu Mizutani, Miya Mizutani, Nobuyoshi Mochizuki, Isabel Monte, Rebecca Mosher, Hideki Nagasaki, Hirofumi Nakagami, Satoshi Naramoto, Kazuhiko Nishitani, Misato Ohtani, Takashi Okamoto, Masaki Okumura, Jeremy Phillips, Bernardo Pollak, Anke Reinders, Moritz Rövekamp, Ryosuke Sano, Shinichiro Sawa, Marc W Schmid, Makoto Shirakawa, Roberto Solano, Alexander Spunde, Noriyuki Suetsugu, Sumio Sugano, Akifumi Sugiyama, Rui Sun, Yutaka Suzuki, Mizuki Takenaka, Daisuke Takezawa, Hirokazu Tomogane, Masayuki Tsuzuki, Takashi Ueda, Masaaki Umeda, John M Ward, Yuichiro Watanabe, Kazufumi Yazaki, Ryusuke Yokoyama, Yoshihiro Yoshitake, Izumi Yotsui, Sabine Zachgo, Jeremy Schmutz

Cell　171　(2)　287-304　2017/10/05

DOI： 10.1016/j.cell.2017.09.030 　

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The evolution of land flora transformed the terrestrial environment. Land plants evolved from an ancestral charophycean alga from which they inherited developmental, biochemical, and cell biological attributes. Additional biochemical and physiological adaptations to land, and a life cycle with an alternation between multicellular haploid and diploid generations that facilitated efficient dispersal of desiccation tolerant spores, evolved in the ancestral land plant. We analyzed the genome of the liverwort Marchantia polymorpha, a member of a basal land plant lineage. Relative to charophycean algae, land plant genomes are characterized by genes encoding novel biochemical pathways, new phytohormone signaling pathways (notably auxin), expanded repertoires of signaling pathways, and increased diversity in some transcription factor families. Compared with other sequenced land plants, M. polymorpha exhibits low genetic redundancy in most regulatory pathways, with this portion of its genome resembling that predicted for the ancestral land plant. PAPERCLIP.
Letter to the Editor: Author Response - Analysis of Rhizome Development in Oryza longistaminata, a Wild Rice Species. Peer-reviewed

Junko Kyozuka

Plant & cell physiology　58　(8)　1283-1283　2017/08/01

DOI： 10.1093/pcp/pcx064 　
Regulation of Strigolactone Biosynthesis by Gibberellin Signaling. International-journal Peer-reviewed

Shinsaku Ito, Daichi Yamagami, Mikihisa Umehara, Atsushi Hanada, Satoko Yoshida, Yasuyuki Sasaki, Shunsuke Yajima, Junko Kyozuka, Miyako Ueguchi-Tanaka, Makoto Matsuoka, Ken Shirasu, Shinjiro Yamaguchi, Tadao Asami

Plant physiology　174　(2)　1250-1259　2017/06

DOI： 10.1104/pp.17.00301 　

ISSN： 0032-0889

eISSN： 1532-2548
Effects of genes increasing the number of spikelets per panicle, TAW1 and APO1, on yield and yield-related traits in rice Peer-reviewed

Akira Fukushima, Hisatoshi Ohta, Narifumi Yokogami, Naoto Tsuda, Akiko Yoshida, Junko Kyozuka, Masahiko Maekawa

Plant Production Science　20　(4)　485-489　2017

DOI： 10.1080/1343943X.2017.1365614 　

ISSN： 1343-943X

eISSN： 1349-1008
Phloem Transport of the Receptor DWARF14 Protein Is Required for Full Function of Strigolactones. International-journal Peer-reviewed

Hiromu Kameoka, Elizabeth A Dun, Mauricio Lopez-Obando, Philip B Brewer, Alexandre de Saint Germain, Catherine Rameau, Christine A Beveridge, Junko Kyozuka

Plant physiology　172　(3)　1844-1852　2016/11

DOI： 10.1104/pp.16.01212 　

ISSN： 0032-0889

eISSN： 1532-2548
Analysis of Rhizome Development in Oryza longistaminata, a Wild Rice Species. Peer-reviewed

Akiko Yoshida, Yasuhiko Terada, Taiyo Toriba, Katsumi Kose, Motoyuki Ashikari, Junko Kyozuka

Plant & cell physiology　57　(10)　2213-2220　2016/10

DOI： 10.1093/pcp/pcw138 　

ISSN： 0032-0781

eISSN： 1471-9053
Cellular and developmental function of ACAP type ARF-GAP proteins are diverged in plant cells. Peer-reviewed

Satoshi Naramoto, Tomoko Dainobu, Hiroki Tokunaga, Junko Kyozuka, Hiroo Fukuda

Plant biotechnology (Tokyo, Japan)　33　(4)　309-314　2016

DOI： 10.5511/plantbiotechnology.16.0309a 　

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Vesicle transport is crucial for various cellular functions and development of multicellular organisms. ARF-GAP is one of the key regulators of vesicle transport and is diverse family of proteins. Arabidopsis has 15 ARF-GAP proteins and four members are classified as ACAP type ARF-GAP proteins. Our previous study identified that VASCULAR NETWORK DEFECTIVE3 (VAN3), an ACAP ARF-GAP, played crucial roles in leaf vascular formation. However, it remains question how other members of plant ACAP ARF-GAPs function in cellular and developmental processes. To characterize these, we analyzed spatial expression pattern and subcellular localization of VAN3 and three other ACAPs, so called VAN3-like proteins (VALs). Expression pattern analysis revealed that they were expressed in distinctive developmental processes. Subcellular localization analysis in protoplast cells indicated that in contrast to VAN3, which localizes on trans-Golgi networks/early endosomes (TGNs/EEs), VAL1 and VAL2 were localized on ARA6-labelled endosomes, and VAL3 resided mainly in the cytoplasm. These results indicated that VAN3 and VALs are differently expressed in a tissue level and function in different intracellular compartments, in spite of their significant sequence similarities. These findings suggested functional divergence among plant ACAPs. Cellular localizations of all members of animal ACAP proteins are identical. Therefore our findings also suggested that plant evolved ACAP proteins in plant specific manner.
Hd3a promotes lateral branching in rice. International-journal Peer-reviewed

Hiroyuki Tsuji, Chika Tachibana, Shojiro Tamaki, Ken-Ichiro Taoka, Junko Kyozuka, Ko Shimamoto

The Plant journal : for cell and molecular biology　82　(2)　256-266　2015/04

DOI： 10.1111/tpj.12811 　

ISSN： 0960-7412

eISSN： 1365-313X
Downregulation of rice DWARF 14 LIKE suppress mesocotyl elongation via a strigolactone independent pathway in the dark. International-journal Peer-reviewed

Hiromu Kameoka, Junko Kyozuka

Journal of genetics and genomics　42　(3)　119-124　2015/03/20

DOI： 10.1016/j.jgg.2014.12.003 　

ISSN： 1673-8527

eISSN： 1873-5533
Lack of cytosolic glutamine synthetase1;2 in vascular tissues of axillary buds causes severe reduction in their outgrowth and disorder of metabolic balance in rice seedlings. International-journal Peer-reviewed

Miwa Ohashi, Keiki Ishiyama, Miyako Kusano, Atsushi Fukushima, Soichi Kojima, Atsushi Hanada, Keiichi Kanno, Toshihiko Hayakawa, Yoshiya Seto, Junko Kyozuka, Shinjiro Yamaguchi, Tomoyuki Yamaya

The Plant journal : for cell and molecular biology　81　(2)　347-356　2015/01

DOI： 10.1111/tpj.12731 　

ISSN： 0960-7412

eISSN： 1365-313X
SAD1, an RNA polymerase I subunit A34.5 of rice, interacts with Mediator and controls various aspects of plant development. International-journal Peer-reviewed

Weiqiang Li, Akiko Yoshida, Megumu Takahashi, Masahiko Maekawa, Mikiko Kojima, Hitoshi Sakakibara, Junko Kyozuka

The Plant journal : for cell and molecular biology　81　(2)　282-291　2015/01

DOI： 10.1111/tpj.12725 　

ISSN： 0960-7412

eISSN： 1365-313X
Strigolactone and cytokinin act antagonistically in regulating rice mesocotyl elongation in darkness. Peer-reviewed

Zhongyuan Hu, Takaki Yamauchi, Jinghua Yang, Yusuke Jikumaru, Tomoko Tsuchida-Mayama, Hiroaki Ichikawa, Itsuro Takamure, Yoshiaki Nagamura, Nobuhiro Tsutsumi, Shinjiro Yamaguchi, Junko Kyozuka, Mikio Nakazono

Plant & cell physiology　55　(1)　30-41　2014/01

DOI： 10.1093/pcp/pct150 　

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Strigolactones (SLs) are a group of phytohormones that control plant growth and development including shoot branching. Previous studies of the phenotypes of SL-related rice (Oryza sativa) dwarf (d) mutants demonstrated that SLs inhibit mesocotyl elongation by controlling cell division. Here, we found that the expression of cytokinin (CK)-responsive type-A RESPONSE REGULATOR (RR) genes was higher in d10-1 and d14-1 mutants than in the wild type. However, CK levels in mesocotyls of the d mutants were not very different from those in the wild type. On the other hand, application of a synthetic CK (kinetin) enhanced mesocotyl elongation in the d mutants and the wild type. d10-1 and d14-1 mesocotyls were more sensitive to CK than wild-type mesocotyls, suggesting that the up-regulation of the CK-responsive type-A RR genes and the higher elongation of mesocotyls in the d mutants are mainly due to the increased sensitivity of the d mutants to CK. Co-treatment with kinetin and a synthetic SL (GR24) confirmed the antagonistic functions of SL and CK on mesocotyl elongation. OsTCP5, which encodes a transcription factor belonging to the cell division-regulating TCP family, was also regulated by SL and CK and its expression was negatively correlated with mesocotyl length. These findings suggest that OsTCP5 contributes to the SL- and CK-controlled mesocotyl elongation in darkness.
Structures of D14 and D14L in the strigolactone and karrikin signaling pathways. International-journal Peer-reviewed

Megumi Kagiyama, Yoshinori Hirano, Tomoyuki Mori, Sun-Yong Kim, Junko Kyozuka, Yoshiya Seto, Shinjiro Yamaguchi, Toshio Hakoshima

Genes to cells : devoted to molecular & cellular mechanisms　18　(2)　147-160　2013/02

DOI： 10.1111/gtc.12025 　

ISSN： 1356-9597 1365-2443
TAWAWA1, a regulator of rice inflorescence architecture, functions through the suppression of meristem phase transition. International-journal Peer-reviewed

Akiko Yoshida, Masafumi Sasao, Naoko Yasuno, Kyoko Takagi, Yasufumi Daimon, Ruihong Chen, Ryo Yamazaki, Hiroki Tokunaga, Yoshinori Kitaguchi, Yutaka Sato, Yoshiaki Nagamura, Tomokazu Ushijima, Toshihiro Kumamaru, Shigeru Iida, Masahiko Maekawa, Junko Kyozuka

Proceedings of the National Academy of Sciences of the United States of America　110　(2)　767-772　2013/01/08

DOI： 10.1073/pnas.1216151110 　

ISSN： 0027-8424
The D3 F-box protein is a key component in host strigolactone responses essential for arbuscular mycorrhizal symbiosis. International-journal Peer-reviewed

Satoko Yoshida, Hiromu Kameoka, Misaki Tempo, Kohki Akiyama, Mikihisa Umehara, Shinjiro Yamaguchi, Hideo Hayashi, Junko Kyozuka, Ken Shirasu

The New phytologist　196　(4)　1208-1216　2012/12

DOI： 10.1111/j.1469-8137.2012.04339.x 　

ISSN： 0028-646X
Control of tiller growth of rice by OsSPL14 and Strigolactones, which work in two independent pathways. Peer-reviewed

Le Luo, Weiqiang Li, Kotaro Miura, Motoyuki Ashikari, Junko Kyozuka

Plant & cell physiology　53　(10)　1793-1801　2012/10

DOI： 10.1093/pcp/pcs122 　

ISSN： 0032-0781
Strigolactone Positively Controls Crown Root Elongation in Rice Peer-reviewed

Tomotsugu Arite, Hiromu Kameoka, Junko Kyozuka

J. Plant Growth Regul　31　(2)　165-172　2012/06

DOI： 10.1007/s00344-011-9228-6 　

ISSN： 0721-7595
Inflorescence meristem identity in rice is specified by overlapping functions of three AP1/FUL-like MADS box genes and PAP2, a SEPALLATA MADS box gene. International-journal Peer-reviewed

Kaoru Kobayashi, Naoko Yasuno, Yutaka Sato, Masahiro Yoda, Ryo Yamazaki, Mayumi Kimizu, Hitoshi Yoshida, Yoshiaki Nagamura, Junko Kyozuka

The Plant cell　24　(5)　1848-1859　2012/05

DOI： 10.1105/tpc.112.097105 　

ISSN： 1040-4651
The bHLH Rac Immunity1 (RAI1) Is Activated by OsRac1 via OsMAPK3 and OsMAPK6 in Rice Immunity. Peer-reviewed

Sung-Hyun Kim, Tetsuo Oikawa, Junko Kyozuka, Hann Ling Wong, Kenji Umemura, Mitsuko Kishi-Kaboshi, Akira Takahashi, Yoji Kawano, Tsutomu Kawasaki, Ko Shimamoto

Plant & cell physiology　53　(4)　740-754　2012/04

DOI： 10.1093/pcp/pcs033 　

ISSN： 0032-0781
Low-affinity cation transporter (OsLCT1) regulates cadmium transport into rice grains. International-journal Peer-reviewed

Shimpei Uraguchi, Takehiro Kamiya, Takuya Sakamoto, Koji Kasai, Yutaka Sato, Yoshiaki Nagamura, Akiko Yoshida, Junko Kyozuka, Satoru Ishikawa, Toru Fujiwara

Proceedings of the National Academy of Sciences of the United States of America　108　(52)　20959-20964　2011/12/27

DOI： 10.1073/pnas.1116531109 　

ISSN： 0027-8424
LAX PANICLE2 of rice encodes a novel nuclear protein and regulates the formation of axillary meristems. International-journal Peer-reviewed

Hiroaki Tabuchi, Yu Zhang, Susumu Hattori, Minami Omae, Sae Shimizu-Sato, Tetsuo Oikawa, Qian Qian, Minoru Nishimura, Hidemi Kitano, He Xie, Xiaohua Fang, Hitoshi Yoshida, Junko Kyozuka, Fan Chen, Yutaka Sato

The Plant cell　23　(9)　3276-3287　2011/09

DOI： 10.1105/tpc.111.088765 　

ISSN： 1040-4651
New branching inhibitors and their potential as strigolactone mimics in rice. International-journal Peer-reviewed

Kosuke Fukui, Shinsaku Ito, Kotomi Ueno, Shinjiro Yamaguchi, Junko Kyozuka, Tadao Asami

Bioorganic & medicinal chemistry letters　21　(16)　4905-4908　2011/08/15

DOI： 10.1016/j.bmcl.2011.06.019 　

ISSN： 0960-894X
FINE CULM1 (FC1) works downstream of strigolactones to inhibit the outgrowth of axillary buds in rice. Peer-reviewed

Kosuke Minakuchi, Hiromu Kameoka, Naoko Yasuno, Mikihisa Umehara, Le Luo, Kaoru Kobayashi, Atsushi Hanada, Kotomi Ueno, Tadao Asami, Shinjiro Yamaguchi, Junko Kyozuka

Plant & cell physiology　51　(7)　1127-1135　2010/07

DOI： 10.1093/pcp/pcq083 　

ISSN： 0032-0781
A new lead chemical for strigolactone biosynthesis inhibitors. Peer-reviewed

Shinsaku Ito, Nobutaka Kitahata, Mikihisa Umehara, Atsushi Hanada, Atsutaka Kato, Kotomi Ueno, Kiyoshi Mashiguchi, Junko Kyozuka, Koichi Yoneyama, Shinjiro Yamaguchi, Tadao Asami

Plant & cell physiology　51　(7)　1143-1150　2010/07

DOI： 10.1093/pcp/pcq077 　

ISSN： 0032-0781
Strigolactones negatively regulate mesocotyl elongation in rice during germination and growth in darkness. Peer-reviewed

Zhongyuan Hu, Haifang Yan, Jinghua Yang, Shinjiro Yamaguchi, Masahiko Maekawa, Itsuro Takamure, Nobuhiro Tsutsumi, Junko Kyozuka, Mikio Nakazono

Plant & cell physiology　51　(7)　1136-1142　2010/07

DOI： 10.1093/pcp/pcq075 　

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Strigolactones (SLs) are newly discovered plant hormones that regulate plant growth and development including shoot branching. They also stimulate symbiosis with arbuscular mycorrhizal fungi. Rice has at least three genes that are involved in SL synthesis (D10, D17/HTD1 and D27) and at least two genes that are involved in SL signaling (D3) and SL signaling or downstream metabolism (D14/D88/HTD2). We observed that mesocotyl elongation in darkness was greater in rice mutants defective in these genes than in the wild type. Exogenous application of a synthetic SL analog, GR24, rescued the phenotype of mesocotyl elongation in the SL-deficient mutants, d10-1, d17-1 and d27-1, in a dose-dependent manner, but did not affect mesocotyl lengths of the SL-insensitive mutants, d3-1 and d14-1. No significant differences in cell length were found between the d mutants and the wild type, except for some cells on the lower half of the d3-1 mesocotyl that were shortened. On the other hand, the number of cells in the mesocotyls was 3- to 6-fold greater in the d mutants than in the wild type. Treatment with GR24 reduced the number of cells in the d10-1 mesocotyl to the wild-type level, but did not affect the number of cells in the d3-1 and d14-1 mesocotyls. These findings indicate that SLs negatively regulate cell division, but not cell elongation, in the mesocotyl during germination and growth of rice in darkness.
PANICLE PHYTOMER2 (PAP2), encoding a SEPALLATA subfamily MADS-box protein, positively controls spikelet meristem identity in rice. Peer-reviewed

Kaoru Kobayashi, Masahiko Maekawa, Akio Miyao, Hirohiko Hirochika, Junko Kyozuka

Plant & cell physiology　51　(1)　47-57　2010/01

DOI： 10.1093/pcp/pcp166 　

ISSN： 0032-0781
Signal peptide peptidases are expressed in the shoot apex of rice, localized to the endoplasmic reticulum. International-journal Peer-reviewed

Tomoko Tamura, Masaharu Kuroda, Tetsuo Oikawa, Junko Kyozuka, Kaede Terauchi, Yoshiro Ishimaru, Keiko Abe, Tomiko Asakura

Plant cell reports　28　(11)　1615-1621　2009/11

DOI： 10.1007/s00299-009-0760-9 　

ISSN： 0721-7714
d14, a strigolactone-insensitive mutant of rice, shows an accelerated outgrowth of tillers. Peer-reviewed

Tomotsugu Arite, Mikihisa Umehara, Shinji Ishikawa, Atsushi Hanada, Masahiko Maekawa, Shinjiro Yamaguchi, Junko Kyozuka

Plant & cell physiology　50　(8)　1416-1424　2009/08

DOI： 10.1093/pcp/pcp091 　

ISSN： 0032-0781
Expression level of ABERRANT PANICLE ORGANIZATION1 determines rice inflorescence form through control of cell proliferation in the meristem. International-journal Peer-reviewed

Kyoko Ikeda-Kawakatsu, Naoko Yasuno, Tetsuo Oikawa, Shigeru Iida, Yasuo Nagato, Masahiko Maekawa, Junko Kyozuka

Plant physiology　150　(2)　736-747　2009/06

DOI： 10.1104/pp.109.136739 　

ISSN： 0032-0889
Short panicle1 encodes a putative PTR family transporter and determines rice panicle size. International-journal Peer-reviewed

Shengben Li, Qian Qian, Zhiming Fu, Dali Zeng, Xiangbing Meng, Junko Kyozuka, Masahiko Maekawa, Xudong Zhu, Jian Zhang, Jiayang Li, Yonghong Wang

The Plant journal : for cell and molecular biology　58　(4)　592-605　2009/05

DOI： 10.1111/j.1365-313X.2009.03799.x 　

ISSN： 0960-7412
Two-Step Regulation of LAX PANICLE1 Protein Accumulation in Axillary Meristem Formation in Rice. International-journal Peer-reviewed

Tetsuo Oikawa, Junko Kyozuka

The Plant cell　21　(4)　1095-1108　2009/04

DOI： 10.1105/tpc.108.065425 　

ISSN： 1040-4651
Inhibition of shoot branching by new terpenoid plant hormones. International-journal Peer-reviewed

Mikihisa Umehara, Atsushi Hanada, Satoko Yoshida, Kohki Akiyama, Tomotsugu Arite, Noriko Takeda-Kamiya, Hiroshi Magome, Yuji Kamiya, Ken Shirasu, Koichi Yoneyama, Junko Kyozuka, Shinjiro Yamaguchi

Nature　455　(7210)　195-200　2008/09/11

DOI： 10.1038/nature07272 　

ISSN： 0028-0836
Gain-of-function phenotypes of chemically synthetic CLAVATA3/ESR-related (CLE) peptides in Arabidopsis thaliana and Oryza sativa (Plant and Cell Physiology 48 12, (1821-1825)) Peer-reviewed

Atsuko Kinoshita, Yasukazu Nakamura, Erika Sasaki, Junko Kyozuka, Hiroo Fukuda, Shinichiro Sawa

Plant & cell physiology　49　(6)　999-999　2008

DOI： 10.1093/pcp/pcn071 　
Rice ABERRANT PANICLE ORGANIZATION 1, encoding an F-box protein, regulates meristem fate. International-journal Peer-reviewed

Kyoko Ikeda, Momoyo Ito, Nobuhiro Nagasawa, Junko Kyozuka, Yasuo Nagato

The Plant journal : for cell and molecular biology　51　(6)　1030-1040　2007/09

DOI： 10.1111/j.1365-313X.2007.03200.x 　

ISSN： 0960-7412
DWARF10, an RMS1/MAX4/DAD1 ortholog, controls lateral bud outgrowth in rice. International-journal Peer-reviewed

Tomotsugu Arite, Hirotaka Iwata, Kenji Ohshima, Masahiko Maekawa, Masatoshi Nakajima, Mikiko Kojima, Hitoshi Sakakibara, Junko Kyozuka

The Plant journal : for cell and molecular biology　51　(6)　1019-1029　2007/09

DOI： 10.1111/j.1365-313X.2007.03210.x 　

ISSN： 0960-7412
Rice tillering dwarf mutant dwarf3 has increased leaf longevity during darkness-induced senescence or hydrogen peroxide-induced cell death. Peer-reviewed

Haifang Yan, Hiroaki Saika, Masahiko Maekawa, Itsuro Takamure, Nobuhiro Tsutsumi, Junko Kyozuka, Mikio Nakazono

Genes & genetic systems　82　(4)　361-366　2007/08

DOI： 10.1266/ggs.82.361 　

ISSN： 1341-7568

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Senescence or cell death in plant leaves is known to be inducible by darkness or H(2)O(2). When the Arabidopsis gene MAX2/ORE9 is disrupted, leaf senescence or cell death in response to the above stimuli is delayed. Because the rice (Oryza sativa L.) gene DWARF3 (D3) is orthologous to MAX2/ORE9, we wished to know whether disruption of D3 also results in increased longevity in leaves. We found that darkness-induced senescence or H(2)O(2)-induced cell death in the third leaf [as measured by chlorophyll degradation, membrane ion leakage and expression of senescence-associated genes (SAGs)] in a d3 rice mutant was delayed by 1-3 d compared to that in its reference line Shiokari. Moreover, the mRNA levels of D3, HTD1 and D10, which are orthologs of Arabidopsis MAX2/ORE9, MAX3 and MAX4, respectively, increased during cell death. These results suggest that D3 protein in rice, like MAX2/ORE9 in Arabidopsis, is involved in leaf senescence or cell death.
Characterization of OsPID, the rice ortholog of PINOID, and its possible involvement in the control of polar auxin transport. Peer-reviewed

Yutaka Morita, Junko Kyozuka

Plant & cell physiology　48　(3)　540-549　2007/03

DOI： 10.1093/pcp/pcm024 　

ISSN： 0032-0781
Direct control of shoot meristem activity by a cytokinin-activating enzyme. International-journal Peer-reviewed

Takashi Kurakawa, Nanae Ueda, Masahiko Maekawa, Kaoru Kobayashi, Mikiko Kojima, Yasuo Nagato, Hitoshi Sakakibara, Junko Kyozuka

Nature　445　(7128)　652-655　2007/02/08

DOI： 10.1038/nature05504 　

ISSN： 0028-0836

eISSN： 1476-4687
Analyses of ABERRANT PANICLE ORGANIZATION 1 (APO1) gene regulating the spikelet number in rice. Peer-reviewed

Kyoko Ikeda, Nobuhiro Nagasawa, Mornoyo Itoh, Junko Kyozuka, Yasuo Nagato

Plant & cell physiology　48　S52-S52　2007

ISSN： 0032-0781
Genome-wide analysis of spatial and temporal gene expression in rice panicle development. International-journal Peer-reviewed

Ikuyo Furutani, Shin Sukegawa, Junko Kyozuka

The Plant journal : for cell and molecular biology　46　(3)　503-511　2006/05

DOI： 10.1111/j.1365-313X.2006.02703.x 　

ISSN： 0960-7412
Suppression of tiller bud activity in tillering dwarf mutants of rice. Peer-reviewed

Shinji Ishikawa, Masahiko Maekawa, Tomotsugu Arite, Kazumitsu Onishi, Itsuro Takamure, Junko Kyozuka

Plant & cell physiology　46　(1)　79-86　2005/01

DOI： 10.1093/pcp/pci022 　

ISSN： 0032-0781
The role of barren stalk1 in the architecture of maize. International-journal Peer-reviewed

Andrea Gallavotti, Qiong Zhao, Junko Kyozuka, Robert B Meeley, Matthew K Ritter, John F Doebley, M Enrico Pè, Robert J Schmidt

Nature　432　(7017)　630-635　2004/12/02

DOI： 10.1038/nature03148 　

ISSN： 0028-0836

eISSN： 1476-4687
Identification of rice PIN homologs Peer-reviewed

Yutaka Morita, Junko Kyozuka

Rice Genetics Newsletter　21　87-88　2004
Lonely guy is a new regulator of meristem maintenance in rice. Peer-reviewed

Rice Genetics Newsletter　21　81-82　2004
Partial conservation of LFY function between rice and Arabidopsis. Peer-reviewed

Atsushi Chujo, Ze Zhang, Hirohisa Kishino, Ko Shimamoto, Junko Kyozuka

Plant & cell physiology　44　(12)　1311-1319　2003/12

DOI： 10.1093/pcp/pcg155 　

ISSN： 0032-0781
LAX and SPA: major regulators of shoot branching in rice. International-journal Peer-reviewed

Keishi Komatsu, Masahiko Maekawa, Shin Ujiie, Yuzuki Satake, Ikuyo Furutani, Hironobu Okamoto, Ko Shimamoto, Junko Kyozuka

Proceedings of the National Academy of Sciences of the United States of America　100　(20)　11765-11770　2003/09/30

DOI： 10.1073/pnas.1932414100 　

ISSN： 0027-8424
Two-step regulation and continuous retrotransposition of the rice LINE-type retrotransposon Karma. International-journal Peer-reviewed

Mai Komatsu, Ko Shimamoto, Junko Kyozuka

The Plant cell　15　(8)　1934-1944　2003/08

DOI： 10.1105/tpc.011809 　

ISSN： 1040-4651
FRIZZY PANICLE is required to prevent the formation of axillary meristems and to establish floral meristem identity in rice spikelets. International-journal Peer-reviewed

Mai Komatsu, Atsushi Chujo, Yasuo Nagato, Ko Shimamoto, Junko Kyozuka

Development (Cambridge, England)　130　(16)　3841-3850　2003/08

DOI： 10.1242/dev.00564 　

ISSN： 0950-1991
Overexpression of RCN1 and RCN2, rice TERMINAL FLOWER 1/CENTRORADIALIS homologs, confers delay of phase transition and altered panicle morphology in rice. International-journal Peer-reviewed

Mayu Nakagawa, Ko Shimamoto, Junko Kyozuka

The Plant journal : for cell and molecular biology　29　(6)　743-750　2002/03

DOI： 10.1046/j.1365-313X.2002.01255.x 　

ISSN： 0960-7412
Ectopic expression of OsMADS3, a rice ortholog of AGAMOUS, caused a homeotic transformation of lodicules to stamens in transgenic rice plants. Peer-reviewed

Junko Kyozuka, Ko Shimamoto

Plant & cell physiology　43　(1)　130-135　2002/01

DOI： 10.1093/pcp/pcf010 　

ISSN： 0032-0781
A Ca(2+)-dependent protein kinase that endows rice plants with cold- and salt-stress tolerance functions in vascular bundles. Peer-reviewed

Yusuke Saijo, Natsuko Kinoshita, Keiki Ishiyama, Shingo Hata, Junko Kyozuka, Toshihiko Hayakawa, Teiji Nakamura, Ko Shimamoto, Tomoyuki Yamaya, Katsura Izui

Plant & cell physiology　42　(11)　1228-1233　2001/11

DOI： 10.1093/pcp/pce158 　

ISSN： 0032-0781
The LAX1 and FRIZZY PANICLE 2 genes determine the inflorescence architecture of rice by controlling rachis-branch and spikelet development. International-journal Peer-reviewed

Mai Komatsu, Masahiko Maekawa, Ko Shimamoto, Junko Kyozuka

Developmental biology　231　(2)　364-373　2001/03/15

DOI： 10.1006/dbio.2000.9988 　

ISSN： 0012-1606
Over-expression of a single Ca2+-dependent protein kinase confers both cold and salt/drought tolerance on rice plants. International-journal Peer-reviewed

Yusuke Saijo, Shingo Hata, Junko Kyozuka, Ko Shimamoto, Katsura Izui

The Plant journal : for cell and molecular biology　23　(3)　319-327　2000/08

DOI： 10.1046/j.1365-313X.2000.00787.x 　

ISSN： 0960-7412
Insect- and herbicide-resistant transgenic eucalypts Peer-reviewed

R.L. Harcourt, J. Kyozuka, R.B. Floyd, K.S. Bateman, H. Tanaka, V. Decroocq, D.J. Llewellyn, X. Zhu, W.J. Peacock, E.S. Dennis

Molecular Breeding　6　(3)　307-315　2000/06
Publisher: Springer Science and Business Media LLC
DOI： 10.1023/a:1009676214328 　

ISSN： 1380-3743
Spatially and temporally regulated expression of rice MADS box genes with similarity to Arabidopsis class A, B and C genes. Peer-reviewed

Junko Kyozuka, Takeshi Kobayashi, Masakazu Morita, Ko Shimamoto

Plant & cell physiology　41　(6)　710-718　2000/06

ISSN： 0032-0781
Ac as a tool for the functional genomics of rice. International-journal Peer-reviewed

H. Enoki, T. Izawa, M. Kawahara, M. Komatsu, S. Koh, J. Kyozuka, K. Shimamoto

The Plant journal : for cell and molecular biology　19　(5)　605-613　1999/09

ISSN： 0960-7412

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To examine whether the maize autonomous transposable element Ac can be used for the functional analysis of the rice genome, we used Southern blot analysis to analyze the behaviour of Ac in 559 rice plants of four transgenic families through three successive generations. All families showed highly active transposition of Ac, and 103 plants (18.4%) contained newly transposed Ac insertions. In nine of the 12 independent transpositions analyzed, their germinal transmission was detected. Partial sequencing of 99 Ac-flanking sequences revealed that 21 clones exhibited significant similarities with protein-coding genes in databases and four of them matched rice cDNA sequences. These results indicate preferential Ac transposition into protein-coding rice genes. To examine the feasibility of PCR-based screening of gene knockouts in rice Ac plants, we prepared bulked genomic DNA from the leaves of approximately 6000 rice Ac plants and pooled the DNA according to a three-dimensional matrix. Of 14 randomly selected genes, two gene knockouts were identified, and one encoding a rice cytochrome P450 (CYP86) gene was shown to be stably inherited to the progeny. Together, these results suggest that Ac can be efficiently used for the functional analysis of the rice genome.
A TM3-like MADS-box gene from Eucalyptus expressed in both vegetative and reproductive tissues. International-journal Peer-reviewed

V. Decroocq, X. Zhu, M. Kauffman, J. Kyozuka, W. J. Peacock, E. S. Dennis, D. J. Llewellyn

Gene　228　(1-2)　155-160　1999/03/04

ISSN： 0378-1119

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MADS-box genes in plants are a diverse class of transcription factors that are involved in regulating developmental processes, particularly meristem and organ identity during floral development. They are characterized by a highly conserved MADS-box domain of 59 amino acids that binds to specific DNA sequences. We report the characterization of a cDNA clone, ETL (Eucalyptus TM3 Like), from Eucalyptus globulus subspecies bicostata encoding a putative transcription factor of the MADS-box class that is strongly expressed in both vegetative and floral tissues, suggesting that it regulates processes other than floral development. The clone was isolated from a floral bud cDNA library with a probe generated from Eucalyptus genomic DNA by PCR using degenerate primers to the MADS-box of the floral regulatory gene APETALA 1. The ETL cDNA clone encodes a putative protein of 206 amino acids that contains an N-terminal MADS-box and a helical domain of approx. 60 amino acids predicted to form a coiled-coil (K-box). These structural features are characteristic of plant MADS-box proteins. The MADS-box domain contains all the signature residues of a class of MADS-box genes typified by the tomato gene TM3 and overall, ETL shows 56% amino acid identity to TM3. Like TM3, the ETL gene is expressed in both vegetative and reproductive organs, predominantly in root and shoot meristems and organ primordia, as well as in developing male and female floral organs.
Down-regulation of RFL, the FLO/LFY homolog of rice, accompanied with panicle branch initiation. International-journal Peer-reviewed

J. Kyozuka, S. Konishi, K. Nemoto, T. Izawa, K. Shimamoto

Proceedings of the National Academy of Sciences of the United States of America　95　(5)　1979-1982　1998/03/03

ISSN： 0027-8424

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FLORICAULA (FLO) of Antirrhinum and LEAFY (FLY) of Arabidopsis regulate the formation of floral meristems. To examine whether same mechanisms control floral development in distantly related species such as grasses, we isolated RFL, FLO-LFY homolog of rice, and examined its expression and function. Northern analysis showed that RFL is expressed predominantly in very young panicle but not in mature florets, mature leaves, or roots. In situ hybridization revealed that RFL RNA was expressed in epidermal cells in young leaves at vegetative growth stage. After the transition to reproductive stage, RFL RNA was detected in all layers of very young panicle including the apical meristem, but absent in the incipient primary branches. As development of branches proceeds, RFL RNA accumulation localized in the developing branches except for the apical meristems of the branches and secondary branch primordia. Expression pattern of RFL raised a possibility that, unlike FLO and LFY, RFL might be involved in panicle branching. Transgenic Arabidopsis plants constitutively expressing RFL from the cauliflower mosaic virus 35S promoter were produced to test whether 35S-RFL would cause similar phenotype as observed in 35S-LFY plants. In 35S-RFL plants, transformation of inflorescence meristem to floral meristem was rarely observed. Instead, development of cotyledons, rosette leaves, petals, and stamens was severely affected, demonstrating that RFL function is distinct from that of LFY. Our results suggest that mechanisms controlling floral development in rice might be diverged from that of Arabidopsis and Antirrhinum.
Eucalyptus has functional equivalents of the Arabidopsis AP1 gene. International-journal Peer-reviewed

J. Kyozuka, R. Harcourt, W. J. Peacock, E. S. Dennis

Plant molecular biology　35　(5)　573-584　1997/11

ISSN： 0167-4412

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Two Eucalyptus homologues of the Arabidopsis floral homeotic gene AP1 (EAP1 and EAP2) show 60-65% homology to AP1. EAP1 and EAP2 are expressed predominantly in flower buds. EAP2 produces two different polypeptides arising from differential splicing at an intron, the shorter EAP2 protein diverging from the longer sequence after amino acid 197 and having a translation stop after residue 206. This truncated protein includes both MADS- and K-box amino acid sequences. Ectopic expression of the EAP1 or either of the two EAP2 polypeptides in Arabidopsis driven by the 35S promoter produces effects similar to the corresponding AP1 construct, causing plants to flower earlier, have shorter bolts and resemble the terminal flower mutant (tfl).
The promoters of two carboxylases in a C4 plant (maize) direct cell-specific, light-regulated expression in a C3 plant (rice). International-journal Peer-reviewed

M. Matsuoka, J. Kyozuka, K. Shimamoto, Y. Kano-Murakami

The Plant journal : for cell and molecular biology　6　(3)　311-319　1994/09

ISSN： 0960-7412

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C4 plants have two carboxylases which function in photosynthesis. One, phosphoenolpyruvate carboxylase (PEPC) is localized in mesophyll cells, and the other, ribulose bisphosphate carboxylase (RuBPC) is found in bundle sheath cells. In contrast, C3 plants have only one photosynthetic carboxylase, RuBPC, which is localized in mesophyll cells. The expression of PEPC in C3 mesophyll cells is quite low relative to PEPC expression in C4 mesophyll cells. Two chimeric genes have been constructed consisting of the structural gene encoding beta-glucuronidase (GUS) controlled by two promoters from C4 (maize) photosynthetic genes: (i) the PEPC gene (pepc) and (ii) the small subunit of RuBPC (rbcS). These constructs were introduced into a C3 cereal, rice. Both chimeric genes were expressed almost exclusively in mesophyll cells in the leaf blades and leaf sheaths at high levels, and no or very little activity was observed in other cells. The expression of both genes was also regulated by light. These observations indicate that the regulation systems which direct cell-specific and light-inducible expression of pepc and rbcS in C4 plants are also present in C3 plants. Nevertheless, expression of endogenous pepc in C3 plants is very low in C3 mesophyll cells, and the cell specificity of rbcS expression in C3 plants differs from that in C4 plants. Rice nuclear extracts were assayed for DNA-binding protein(s) which interact with a cis-regulatory element in the pepc promoter. Gel-retardation assays indicate that a nuclear protein with similar DNA-binding specificity to a maize nuclear protein is present in rice.(ABSTRACT TRUNCATED AT 250 WORDS)
Promoter elements required for developmental expression of the maize Adh1 gene in transgenic rice. International-journal Peer-reviewed

J. Kyozuka, M. Olive, W. J. Peacock, E. S. Dennis, K. Shimamoto

The Plant cell　6　(6)　799-810　1994/06

ISSN： 1040-4651

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To define the regions of the maize alcohol dehydrogenase 1 (Adh1) promoter that confer tissue-specific expression, a series of 5' promoter deletions and substitution mutations were linked to the Escherichia coli beta-glucuronidase A (uidA) reporter gene and introduced into rice plants. A region between -140 and -99 not only conferred anaerobically inducible expression in the roots of transgenic plants but was also required for expression in the root cap, embryo, and in endosperm under aerobic conditions. GC-rich (GC-1, GC-2, and GC-3) or GT-rich (GT-1 and GT-2) sequence motifs in this region were necessary for expression in these tissues, as they were in anaerobic expression. Expression in the root cap under aerobic conditions required all the GC- and GT-rich motifs. The GT-1, GC-1, GC-2, and GC-3 motifs, and to a lesser extent the GT-2 motif, were also required for anaerobic responsiveness in rice roots. All elements except the GC-3 motif were needed for endosperm-specific expression. The GC-2 motif and perhaps the GT-1 motif appeared to be the only elements required for high-level expression in the embryos of rice seeds. Promoter regions important for shoot-, embryo-, and pollen-specific expression were proximal to -99, and nucleotides required for shoot-specific expression occurred between positions -72 and -43. Pollen-specific expression required a sequence element outside the promoter region, between +54 and +106 of the untranslated leader, as well as a silencer element in the promoter between -72 and -43.
Insect resistant rice generated by introduction of a modified delta-endotoxin gene of Bacillus thuringiensis. International-journal Peer-reviewed

H. Fujimoto, K. Itoh, M. Yamamoto, J. Kyozuka, K. Shimamoto

Bio/technology (Nature Publishing Company)　11　(10)　1151-1155　1993/10

ISSN： 0733-222X

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As a first step towards development of insect resistant rice we have introduced a truncated delta-endotoxin gene, cryIA(b) of Bacillus thuringiensis (B.t.) which has specific biological activity against lepidopteran insects into a japonica rice. To highly express the cryIA(b) gene in rice the coding sequence was extensively modified based on the codon usage of rice genes. Transgenic plants efficiently expressed the modified cryIA(b) gene at both mRNA and protein levels. Bioassays using R2 generation plants with two major rice insect pests, striped stemborer (Chilo suppressalis) and leaffolder (Cnaphalocrosis medinalis), indicated that transgenic rice plants expressing the CryIA(b) protein are more resistant to these pests than untransformed control plants. Our results suggest that the B.t. endotoxin genes will be useful for the rational development of new rice varieties resistant to major insect pests.
Light-regulated and cell-specific expression of tomato rbcS-gusA and rice rbcS-gusA fusion genes in transgenic rice. International-journal Peer-reviewed

J. Kyozuka, D. McElroy, T. Hayakawa, Y. Xie, R Wu, K. Shimamoto

Plant physiology　102　(3)　991-1000　1993/07

ISSN： 0032-0889

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A previously isolated rice (Oryza sativa) rbcS gene was further characterized. This analysis revealed specific sequences in the 5' regulatory region of the rice rbcS gene that are conserved in rbcS genes of other monocotyledonous species. In transgenic rice plants, we examined the expression of the beta-glucuronidase (gusA) reporter gene directed by the 2.8-kb promoter region of the rice rbcS gene. To examine differences in the regulation of monocotyledonous and dicotyledonous rbcS promoters, the activity of a tomato rbcS promoter was also investigated in transgenic rice plants. Our results indicated that both rice and tomato rbcS promoters confer mesophyll-specific expression of the gusA reporter gene in transgenic rice plants and that this expression is induced by light. However, the expression level of the rice rbcS-gusA gene was higher than that of the tomato rbcS-gusA gene, suggesting the presence of quantitative differences in the activity of these particular monocotyledonous and dicotyledonous rbcS promoters in transgenic rice. Histochemical analysis of rbcS-gusA gene expression showed that the observed light induction was only found in mesophyll cells. Furthermore, it was demonstrated that the light regulation of rice rbcS-gusA gene expression was primarily at the level of mRNA accumulation. We show that the rice rbcS gene promoter should be useful for expression of agronomically important genes for genetic engineering of monocotyledonous species.
Processing followed by complete editing of an altered mitochondrial atp6 RNA restores fertility of cytoplasmic male sterile rice. International-journal Peer-reviewed

M. Iwabuchi, J. Kyozuka, K. Shimamoto

The EMBO journal　12　(4)　1437-1446　1993/04

ISSN： 0261-4189

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Two atp6 genes were found in the mitochondrial genome of cytoplasmic male sterile (CMS) rice carrying the [cms-bo] cytoplasm. One (N-atp6) was identical to the normal cytoplasmic gene, while the second (B-atp6) was identified as a candidate CMS gene by Southern analysis of the mitochondrial genome of CMS cybrid rice. The coding sequence of B-atp6 was identical to the normal N-atp6 gene but its 3'-flanking sequence was different starting at 49 bases downstream from the stop codon. Northern analysis showed that B-atp6 is transcribed into a 2.0 kb RNA in the absence of the Rf-1 gene, whereas two discontinuous RNAs, of approximately 1.5 and 0.45 kb, were detected in the presence of the Rf-1 gene. Determination of the 3' and 5' ends of these RNAs suggested that the two discontinuous RNAs were generated from the 2.0 kb RNA by RNA processing at sites within the B-atp6-specific sequences by the action of the Rf-1 gene. Sequence analysis of cDNA clones derived from the N-atp6 RNA and the processed and unprocessed RNAs of B-atp6 indicated that the processed B-atp6 RNAs were edited as efficiently as the N-atp6, whereas unedited and partially edited RNAs were detected among unprocessed RNAs. RNA processing by Rf-1 thus influences the sequential post-transcriptional editing of the B-atp6 RNAs. Because the unprocessed RNAs of B-atp6 are possibly translated into altered polypeptides, our results suggest that interaction of RNA processing and editing plays a role in controlling CMS expression and the restoration of fertility in rice.
The presequence of a precursor to the delta-subunit of sweet potato mitochondrial F1ATPase is not sufficient for the transport of beta-glucuronidase (GUS) into mitochondria of tobacco, rice and yeast cells. Peer-reviewed

T. Kimura, S. Takeda, J. Kyozuka, T. Asahi, K. Shimamoto, K. Nakamura

Plant & cell physiology　34　(2)　345-355　1993/03

ISSN： 0032-0781

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A precursor to the delta-subunit of sweet potato mitochondrial F1ATPase (pre-F1 delta) has an amino-terminal (N-terminal) presequence of 45 amino acid residues and its N-terminal 18 residues may form an amphiphilic alpha-helix, which is typical of mitochondrial targeting signals [Kimura et al. (1990) J. Biol. Chem. 265: 6079]. Fusion genes consisting of sequences that encoded the 25 (DG25), 46 (DG46) and 73 (DG73) N-terminal amino acids from pre-F1 delta fused to the N-terminus of the coding sequence of bacterial beta-glucuronidase (GUS) were placed downstream of the 35S promoter of cauliflower mosaic virus and used to transform suspension-cultured tobacco cells, rice calli and tobacco plants. Fusion genes were also placed downstream of the yeast GAL10 promoter and introduced into Saccharomyces cerevisiae cells. In these transformed cells, only the DG73 GUS-fusion protein was transported into mitochondria and subjected to proteolytic cleavage of the presequence. Neither transport to mitochondria nor processing of the presequence of the DG46 GUS-fusion protein, which contained the entire presequence and the processing site, occurred in either plant or yeast cells. These results indicate that the presequence of pre-F1 delta is not sufficient for the transport of the GUS protein into mitochondria in tobacco, rice and yeast cells. The requirement for the longer polypeptide from pre-F1 delta in the transport of the GUS protein into mitochondria could be due either to the lack of sufficient information for mitochondrial targeting within the presequence or to the nature of the passenger protein, GUS, used in this study.
Anaerobic induction and tissue-specific expression of maize Adh1 promoter in transgenic rice plants and their progeny. International-journal Peer-reviewed

J. Kyozuka, H. Fujimoto, T. Izawa, K. Shimamoto

Molecular & general genetics : MGG　228　(1-2)　40-48　1991/08

ISSN： 0026-8925

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In order to analyze expression of the maize alcohol dehydrogenase 1 gene (Adh1), its promoter was fused with the gusA reporter gene and introduced into rice by protoplast transformation. Histochemical analysis of transgenic plants and their progeny showed that the maize Adh1 promoter is constitutively expressed in root caps, anthers, anther filaments, pollen, scutellum, endosperm and shoot and root meristem of the embryo. Induction of expression by the Adh1 promoter was examined using seedlings derived from selfed progeny of the transgenic plants. The results showed that expression of the Adh1 promoter was strongly induced (up to 81-fold) in roots of seedlings after 24 h of anaerobic treatment, concomitant with an increase in the level of gusA mRNA. 2,4-D also induced Adh1 promoter-directed expression of gusA to a similar extent. In contrast, little induction by anaerobic treatment was detected in transformed calli, leaves or roots of primary transformants or shoots of seedlings. A detailed examination of seedling roots during anaerobic treatment revealed that the induction started first at the meristem and after 3 h there was strong induction in the elongation zone which is located 1-2 mm above the meristem; the induction then progressed upward from this region. Our results suggest that transgenic rice plants carrying the gusA reporter gene fused with promoters are useful for the study of anaerobic regulation of genes derived from graminaceous species.
Enhancement of foreign gene expression by a dicot intron in rice but not in tobacco is correlated with an increased level of mRNA and an efficient splicing of the intron. International-journal Peer-reviewed

A. Tanaka, S. Mita, S. Ohta, J. Kyozuka, K. Shimamoto, K. Nakamura

Nucleic acids research　18　(23)　6767-6770　1990/12/11

ISSN： 0305-1048

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The first intron of castor bean catalase gene, cat-1 was placed in the N-terminal region of the coding sequence of the beta-glucuronidase gene (gusA) and the intron-containing gusA was used with the cauliflower mosaic virus (CaMV) 35S promoter. Using this plasmid, pIG221, the effect of the intron on expression of beta-glucuronidase (GUS) activity was examined in transgenic rice calli and plants (a monocotyledon), and transgenic tobacco plants (a dicotyledon). The intron-containing plasmid increased the level of GUS enzyme activity 10 to 40-fold and 80 to 90-fold compared with the intronless plasmid, pBI221, in transgenic rice protoplasts and transgenic rice tissues, respectively. In contrast, the presence of the intron hardly influenced the expression of the GUS activity in transgenic tobacco plants. Northern blot analysis showed that the catalase intron was efficiently spliced in rice cells while transgenic tobacco plants contained both spliced and unspliced gusA transcripts in equal amounts. Furthermore, the level of the mature gusA transcript in transformed rice calli was greatly increased in the presence of the intron. The catalase intron was removed at the same splice junctions in transgenic rice and tobacco plants. These findings indicate that the stimulating effect of the intron on GUS expression is correlated with an efficient splicing of pre-mRNA and an increased level of mature mRNA.
Molecular changes in protoplast-derived rice plants. International-journal Peer-reviewed

P. T. Brown, J. Kyozuka, Y. Sukekiyo, Y. Kimura, K. Shimamoto, H. Lörz

Molecular & general genetics : MGG　223　(2)　324-328　1990/09

ISSN： 0026-8925

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To determine whether regeneration of rice plants from protoplast culture induces DNA polymorphisms, progeny plants from direct regenerants of such cultures were examined for restriction fragment length polymorphisms (RFLP analysis). Significantly increased levels of DNA polymorphism were found compared with those in non-tissue culture control plants. Analysis with gene sequences representative of different functional domains, revealed that such polymorphisms are apparently widespread and not associated with any particular region. Analysis by comparative digestion with both methylation-sensitive and insensitive restriction enzymes revealed that methylation changes cannot be regarded as a major factor in the induction of these DNA polymorphisms.
Production of Cytoplasmic Male Sterile Rice (Oryza Sativa L.) by Cell Fusion Peer-reviewed

Junko Kyozuka, Takeo Kaneda, Ko Shimamoto

Bio/technology (Nature Publishing Company)　7　(11)　1171-1174　1989/11
Publisher: Springer Science and Business Media LLC
DOI： 10.1038/nbt1189-1171 　

ISSN： 1087-0156

eISSN： 1546-1696
Yielding ability and phenotypic traits in the selfed progeny of protoplast-derived rice plants. Peer-reviewed

Hisakazu Ogura, Junko Kyozuka, Yasuyuki Hayashi, Ko Shimamoto

Japanese J. Breed　39　(1)　47-56　1989/03
Publisher: Japanese Society of Breeding
DOI： 10.1270/jsbbs1951.39.47 　

ISSN： 0536-3683
Plant regeneration from protoplasts of indica rice: genotypic differences in culture response. International-journal Peer-reviewed

J. Kyozuka, E. Otoo, K. Shimamoto

TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik　76　(6)　887-890　1988/12

DOI： 10.1007/BF00273677 　

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Fourteen varieties of indica rice (Oryza saliva L.) were examined for their capacity for plant regeneration from protoplasts using the nurse culture methods developed for japonica rice. Calli induced from germinating seeds were grouped into two types: type I, white and compact; type II, yellow and friable. In four varieties producing type II callus, colony formation (2%-4.5%) and plant regeneration (2%-35%) were observed. The inability to develop suspension cultures was a major obstacle in regenerating plants from protoplasts of the remaining rice varieties studied.
Hybrids of rice (Oryza sativa L.) and wild Oryza species obtained by cell fusion Peer-reviewed

Yasuyuki Hayashi, Junko Kyozuka, Ko Shimamoto

Molecular & general genetics : MGG　214　(1)　6-10　1988/09
Publisher: Springer Science and Business Media LLC
DOI： 10.1007/bf00340171 　

ISSN： 0026-8925

eISSN： 1432-1874
Plantlet regeneration from somatic hybrids of rice (Oryza sativa L.) and barnyard grass (Echinochloa oryzicola Vasing) Peer-reviewed

Rie Terada, Junko Kyozuka, Soryu Nishibayashi, Ko Shimamoto

Molecular & general genetics : MGG　210　(1)　39-43　1987/11
Publisher: Springer Science and Business Media LLC
DOI： 10.1007/bf00337756 　

ISSN： 0026-8925

eISSN： 1432-1874
Field performance and cytology of protoplast-derived rice (Oryza sativa): high yield and low degree of variation of four japonica cultivars. International-journal Peer-reviewed

H. Ogura, J. Kyozuka, Y. Hayashi, T. Koba, K. Shimamoto

TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik　74　(5)　670-676　1987/09

DOI： 10.1007/BF00288869 　

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Protoplast-derived rice plants of four Japanese cultivars, Nipponbare, Fujisaka 5, Norin 14 and Iwaimochi were individually cultivated in a submerged paddy field. They exhibited more stems, which resulted in more panicles than respective control plants. Other characteristics of protoplast-derived plants were (compared with controls): a slightly shorter or similar culm length, fewer spikelets per panicle, slightly lower seed fertility and similar or lighter 1,000 kernel weight. Grain yield of protoplast-derived plants was more than that of respective control plants in four cultivars. The cause of the higher yield of protoplast-derived plants seems to be mainly due to increased panicle number. Among 126 protoplast-derived plants, 1 triploid, 10 tetraploids and 1 aneuploid were found. Furthermore, 11 variants with low seed fertility showing no gross chromosomal anomalies and one plant with abnormal panicles were found. In total, about 80% of protoplastderived plants showed normal characters. The present results are encouraging for the possibility of rice breeding using protoplasts.
High frequency plant regeneration from rice protoplasts by novel nurse culture methods Peer-reviewed

Junko Kyozuka, Yasuyuki Hayashi, Ko Shimamoto

Molecular & general genetics : MGG　206　(3)　408-413　1987/03
Publisher: Springer Science and Business Media LLC
DOI： 10.1007/bf00428879 　

ISSN： 0026-8925

eISSN： 1432-1874

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Misc. 32

Spatial regulation of strigolactone function. International-journal Peer-reviewed

Hiromu Kameoka, Junko Kyozuka

Journal of experimental botany　69　(9)　2255-2264　2018/04/23
Publisher: Oxford University Press ({OUP})
DOI： 10.1093/jxb/erx434 　

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Strigolactones are plant hormones that control many aspects of plant development and environmental responses. Despite recent and rapid progress in the biochemical and molecular understanding of strigolactone biosynthesis, transport, and signaling, our knowledge about where strigolactones are produced and where they act is fragmented. In this review, we summarize current knowledge about these aspects of strigolactones, obtained from mutant phenotypes, grafting experiments, gene expression patterns, and protein localization studies. We also discuss the potential of new imaging technologies to reveal the spatial regulation of strigolactone function.
The Naming of Names: Guidelines for Gene Nomenclature in Marchantia. Peer-reviewed

John L Bowman, Takashi Araki, Mario A Arteaga-Vazquez, Frederic Berger, Liam Dolan, Jim Haseloff, Kimitsune Ishizaki, Junko Kyozuka, Shih-Shun Lin, Hideki Nagasaki, Hirofumi Nakagami, Keiji Nakajima, Yasukazu Nakamura, Kyoko Ohashi-Ito, Shinichiro Sawa, Masaki Shimamura, Roberto Solano, Hirokazu Tsukaya, Takashi Ueda, Yuichiro Watanabe, Katsuyuki T Yamato, Sabine Zachgo, Takayuki Kohchi

Plant & cell physiology　57　(2)　257-61　2016/02

DOI： 10.1093/pcp/pcv193 　

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While Marchantia polymorpha has been utilized as a model system to investigate fundamental biological questions for over almost two centuries, there is renewed interest in M. polymorpha as a model genetic organism in the genomics era. Here we outline community guidelines for M. polymorpha gene and transgene nomenclature, and we anticipate that these guidelines will promote consistency and reduce both redundancy and confusion in the scientific literature.
Editorial overview: cell signalling and gene regulation: another step up the beaten path. International-journal

Xiangdong Fu, Junko Kyozuka

Current opinion in plant biology　21　iv-vi-VI　2014/10

DOI： 10.1016/j.pbi.2014.10.001 　

ISSN： 1369-5266

eISSN： 1879-0356
Control of grass inflorescence form by the fine-tuning of meristem phase change. International-journal

Junko Kyozuka, Hiroki Tokunaga, Akiko Yoshida

Current opinion in plant biology　17　110-115　2014/02

DOI： 10.1016/j.pbi.2013.11.010 　

ISSN： 1369-5266

eISSN： 1879-0356
Recent advances in strigolactone research: chemical and biological aspects.

Yoshiya Seto, Hiromu Kameoka, Shinjiro Yamaguchi, Junko Kyozuka

Plant & cell physiology　53　(11)　1843-1853　2012/11

DOI： 10.1093/pcp/pcs142 　

ISSN： 0032-0781
Control of plant morphogenesis by plant hormones

Cell technology　30　(2)　132-136　2011
Publisher: 学研メディカル秀潤社
ISSN： 0287-3796
Branching hormone is busy both underground and overground.

Shinjiro Yamaguchi, Junko Kyozuka

Plant & cell physiology　51　(7)　1091-1094　2010/07

DOI： 10.1093/pcp/pcq088 　

ISSN： 0032-0781
New genes in the strigolactone-related shoot branching pathway. International-journal

Christine Anne Beveridge, Junko Kyozuka

Current opinion in plant biology　13　(1)　34-39　2010/02

DOI： 10.1016/j.pbi.2009.10.003 　

ISSN： 1369-5266
イネ科植物の分枝パターンの決定

Plant Morphology　19　29-37　2008
Control of shoot and root meristem function by cytokinin. International-journal

Junko Kyozuka

Current opinion in plant biology　10　(5)　442-446　2007/10

DOI： 10.1016/j.pbi.2007.08.010 　

ISSN： 1369-5266
[Cytokinin biosynthesis and novel activating pathway].

Hitoshi Sakakibara, Junko Kyozuka

Tanpakushitsu kakusan koso. Protein, nucleic acid, enzyme　52　(11)　1322-1329　2007/09

ISSN： 0039-9450
サイトカイニン活性化遺伝子の発見

経塚淳子, 榊原均

化学と生物　45　(9)　602-603　2007
LOG encodes a novel cytokinin activating enzyme that directly controls meristern activity in rice

Nanae Ueda, Mikiko Kojima, Takashi Kurakawa, Masahiko Maekawa, Kaoru Kobayashi, Yasuo Nagato, Junko Kyozuka, Hitoshi Sakakibara

Plant & cell physiology　48　S118-S118　2007

ISSN： 0032-0781
Apical dominance in rice

Tomotsugu Arite, Hirotaka Iwata, Kenji Oshima, Masatoshi Nakajima, Hitoshi Sakakibara, Mikiko Kojima, Masahiko Maekawa, Junko Kyozuka

Plant & cell physiology　48　S81-S81　2007

ISSN： 0032-0781
分枝形成による植物のかたちづくり

経塚淳子

蛋白質・核酸・酵素　51　38-47　2006
The analysis of LOG, a new regulator of shoot apical meristem activity in rice.

T. Kurakawa, M. Maekawa, H. Sakakibara, M. Kojima, H Sato, S Yamaki, Y Nagato, J Kyozuka

Plant & cell physiology　47　S76-S76　2006

ISSN： 0032-0781
Bunketsu-waito, one of tillering dwarf, is controlled by a single recessive gene in rice (Oryza sativa L.).

Breeding Science　55　(2)　193-196　2005

DOI： 10.1270/jsbbs.55.193 　
イネの分げつを制御する遺伝子

経塚淳子

遺伝　57　(6)　19-21　2003/11
Publisher: 裳華房
ISSN： 0387-0022
Rice as a model for comparative genomics of plants. International-journal

Ko Shimamoto, Junko Kyozuka

Annual review of plant biology　53　399-419　2002

ISSN： 1543-5008

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Rapid progress in rice genomics is making it possible to undertake detailed structural and functional comparisons of genes involved in various biological processes among rice and other plant species, such as Arabidopsis. In this review, we summarize the current status of rice genomics. We then select two important areas of research, reproductive development and defense signaling, and compare the functions of rice and orthologous genes in other species involved in these processes. The analysis revealed that apparently orthologous genes can also display divergent functions. Changes in functions and regulation of orthologous genes may represent a basis for diversity among plant species. Such comparative genomics in other plant species will provide important information for future work on the evolution of higher plants.
The LAX PANICLE (LAX) gene of rice is required for axillary meristem initiation in the inflorescence

J Kyozuka, K Komatsu, N Okamoto, M Maekawa, K Shimamoto

Plant & cell physiology　43　S8-S8　2002

ISSN： 0032-0781
Turning floral organs into leaves, leaves into floral organs. International-journal

K Goto, J Kyozuka, J L Bowman

Current opinion in genetics & development　11　(4)　449-456　2001/08

DOI： 10.1016/S0959-437X(00)00216-1 　

ISSN： 0959-437X
植物の生殖、胚発生と結実

経塚淳子

植物分子生理学入門　73-80　1999
Role of RFL, the FLO/LFY homolog of rice (Oryza sativa L.) in panicle development

Junko Kyozuka, Emi Kurokawa, Satoshi Abe, Reiko Matsumura, Masahiko Maekawa, Ko Shimamoto

Flowering Newsletters　26　11-18　1998/11
Flower development of rice.

Junko Kyozuka

Molecular biology of rice　101-118　1998
Publisher: Springer-Verlag Tokyo
Gene silencing in transgenic plants

SHIMAMOTO Ko, MORINO Kazuko, KANNO Tatsuo, KYOZUKA Junko, NAITO Satoshi, ITOH Kimiko

育種学最近の進歩　39　18-21　1997/10
Isolation and characterization of flowering genes from rice

KYOZUKA Junko, MORITA M., KONISHI Saeko, IZAWA T., KOBAYASHI T., NAKAGAWA M., SHIMAMOTO K.

38　39-42　1996
Rice transformation: Methods and application.

Junko Kyozuka, Ko Shimamoto

Transforamtion of plants and soil microorganisms.　53-64　1995
Publisher: Camridge University Press, Cambridge.
植物遺伝子の組織特異的発現を決定するシス因子

経塚淳子

細胞工学別冊、植物細胞工学シリーズ１　107-117　1994
[Analysis of gene expression in cereal species].

J Kyozuka, K Shimamoto

Tanpakushitsu kakusan koso. Protein, nucleic acid, enzyme　37　(7)　1287-1291　1992/05

ISSN： 0039-9450
Transformation and regeneration of rice protoplasts.

Junko Kyozuka, Ko Shimamoto

Plant Tissue Culture Manual　B2　1-17　1991
Publisher: Kluwer Academic Publisher, Netherlands.
[Gene transfer in rice].

J Kyozuka, K Shimamoto

Tanpakushitsu kakusan koso. Protein, nucleic acid, enzyme　34　(14)　1873-1878　1989/11

ISSN： 0039-9450
Regeneration of plants from rice protoplasts.

J. Kyozuka, K. Shimamoto, H. Ogura

Biotechnology in Agriculture and Forestry　8　109-123　1989
Publisher: Springer-Verlag, Berlin Heidelberg.

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Books and Other Publications 6

遺伝のしくみ

経塚淳子

新星出版社　2008

ISBN: 9784405106703
シマウマの縞蝶の模様 : エボデボ革命が解き明かす生物デザインの起源

経塚淳子, 渡辺政隆

光文社　2007/04

ISBN: 9784334961978
モデル植物の実験プロトコール : イネ・シロイヌナズナ・ミヤコグサ編

小松契史, 根本圭介, 経塚淳子

秀潤社　2005

ISBN: 4879622869
新編農学大事典

経塚淳子

養賢堂　2004/03

ISBN: 4842503548
植物の形づくり : 遺伝子から見た分子メカニズム

経塚淳子

共立出版　2003/07

ISBN: 4320056043
植物の形を決める分子機構 : 形態形成を支配する遺伝子のはたらきに迫る

経塚淳子

秀潤社　2000/01

ISBN: 4879622133

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Presentations 15

Strigolactone biosynthesis required for Arbuscular mycorrhizae symbiosis in bryophytes Invited

Shota Shimazaki, Yohei Mizuno, Tomomi Nakagawa, Aino Komatsu, Kiyoshi Mashiguchi, Shinjiro Yamaguchi, Junko Kyozuka

日本植物学会第83回大会　2019/09/15
SL biosynthesis and perception in basal land plants

2018/11/02
KAI2シグナル伝達経路はゼニゴケの形態形成を制御する

水野陽平, 楢本悟史, 小松愛乃, 島崎翔太, 児玉恭一, 石崎公庸, 経塚淳子

日本植物学会　2018/09
Control of leaf and inflorescence morphology by temporal regulation of same genes International-presentation

Junko Kyozuka

Developing Crops of the Future　2016/04/19
メリステム相転換を制御するイネTAWAWA1遺伝子に関する進化発生生物学的解析

楢本悟史, 徳永浩樹, 塚本成幸, 高見英幸, 嶋村正樹, 吉田明希子, 石崎公庸, 西浜竜一, 河内孝之, 経塚淳子

日本分子生物学会年会プログラム・要旨集(Web)　2016
The secret of an underground life - Development of Olyza longistaminata rhizome International-presentation

Junko Kyozuka

Towards Increased Plant Productivity through Understanding of Environmental Responses and Epigenetic Regulation　2015/11/24
Towards a molecular understanding of inflorescence structure determination International-presentation

Junko Kyozuka

ComBio2015　2015/09/29
Marchantia and rice, a new combination to understand the basis of plant development International-presentation

Junko Kyozuka

Marchantia Workshop 2014　2014/12/08
Genome-wide analysis of developmental phase change in rice tiller buds International-presentation

Junko Kyozuka

XII France-Japan Workshop on Plant Science　2014/10/28
Meristem Activity, Inflorescence Form and Yield of Rice International-presentation

Junko Kyozuka

25th International Conference on Arabidopsis Research　2014/07/31
Genome-wide analysis of developmental phase change in rice tiller buds International-presentation

Junko Kyozuka

Cold Spring Harbor Asia Conferences: Genome assisted biology of crops and molecular model plant systems　2014/04/24
イネの穂形成過程におけるトランスクリプトーム解析

大門靖史, 佐藤豊, 安野奈緒子, 小林薫, 依田勝寛, 長村吉晃, 経塚淳子

日本植物生理学会年会要旨集　2013/03/14
Florigen Hd3a protein acts as a mobile branching signal in rice.

TSUJI HIROYUKI, TACHIBANA CHINATSU, TAMAKI SHOJIRO, TAOKA KEN'ICHIRO, KYOZUKA JUNKO, SHIMAMOTO KO

日本植物生理学会年会要旨集　2012/03/09
Strigolactone biosynthesis regulator

Ito Shinsaku, Umehara Mikihisa, Hanada Atsushi, Yoshida Satoko, Kyozuka Junko, Ueguchi-Tanaka Miyako, Matsuoka Makoto, Shirasu Ken, Yamaguchi Shinjiro, Asami Tadao

植物化学調節学会研究発表記録集　2010/10/01

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Parasitic weeds are responsible for large-scale crop devastation all over the world. Parasitic weeds initiate germination by recognizing the secondary metabolites, strigolactones, which are derived from carotenoid and secreted from the roots of the host crops. Strigolactones are also rhizosphere signaling for the symbiotic arbuscular mycorrhizal fungi, and recently, it has been reported that strigolactones and their metabolites act as a novel plant hormone in shoot branching. For the control of parasitic weeds, utilizing the strigolactone biosynthesis inhibitor is one of the promising ways....
Inhibition of shoot branching by strigolactones

Umehara Mikihisa, Hanada Atsushi, Yoshida Satoko, Akiyama Kohki, Arite Tomotsugu, Takeda-Kamiya Noriko, Magome Hiroshi, Kamiya Yuji, Shirasu Ken, Yoneyama Koichi, Kyozuka Junko, Yamaguchi Shinjiro

植物化学調節学会研究発表記録集　2008/10/06

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Shoot branching is an important factor that determines the plant architecture. Two classes of hormones, auxin and cytokinin, have long been known to play key roles in controlling shoot branching. Previous studies using a series of mutants with enhanced shoot branching suggested the existence of a third class of hormone(s), but it has not been chemically identified. Because some of these branching mutants are defective in a carotenoid cleavage dioxygenase (CCD), this new hormone is thought to be synthesized from carotenoids. Strigolactones are a class of terpenoids that were previously found...

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Research Projects 19

ストリゴラクトンを介した植物の環境情報と成長を統御するシステムの原型と進化

経塚淳子, 野村崇人, 山口信次郎, 嶋村正樹, 秋山康紀, 瀬戸義哉, 亀岡啓

Offer Organization: 日本学術振興会

System: 科学研究費助成事業基盤研究(S)

Category: 基盤研究(S)

Institution: 東北大学

2020/08/31 - 2025/03/31
Principles of pluripotent stem cells underlying plant vitality

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)

Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)

Institution: Nara Institute of Science and Technology

2017/06/30 - 2022/03/31
植物幹細胞の多能性を維持するメカニズムの解明

経塚淳子, 豊岡公徳

Offer Organization: 日本学術振興会

System: 科学研究費助成事業新学術領域研究(研究領域提案型)

Category: 新学術領域研究(研究領域提案型)

Institution: 東北大学

2017/06/30 - 2022/03/31
冷害に強い作物を作出するための新規技術基盤の開発

経塚淳子

Offer Organization: 日本学術振興会

System: 科学研究費助成事業挑戦的研究(萌芽)

Category: 挑戦的研究(萌芽)

Institution: 東北大学

2018/06/29 - 2021/03/31
Transport of environmental signals between shoots

Kyozuka Junko, NARAMOTO Satosi, SHIGA Hidetosi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research

Category: Grant-in-Aid for Challenging Exploratory Research

Institution: Tohoku University

2016/04/01 - 2018/03/31

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Plants use variable molecules, such as phyto-hormone, proteins, peptides, as signaling molecules to transmit environmental information. It is crucial for plants to optimize their growth. The basic mechanisms underlying signaling pathways of plant hormones progressed rapidly in the last a few decades, however, the their actual modes in plants grown under natural conditions are poorly understood. In this study, as a first step, we asked whether the signals are transmitted between shoots.
Developement of 4D MRI microscopy for monitoring growth process of rhizome axillary bud

TERADA Yasuhiko, Kose Katsumi, Kyoduka Jyunko, Yoshida Akiko

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

Category: Grant-in-Aid for Scientific Research (C)

Institution: University of Tsukuba

2015/04/01 - 2018/03/31

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We have developed a 4D MRI microimaging system that enables to monitor the grow process of a plant sample, and gained insights into the growth mechanism of the meristem of a rhizome and its environmental response. We designed and implemented the radiofrequency and gradient coils for a cut sample of an axillary bud to obtain information on the morphology, NMR spectrum, and relaxation times at high speed. We also observed and analyzed the grow process of the meristem of the axillary bud.
Integrated Analysis of Strategies for Plant Survival and Growth in Response to Global Environmental Changes

JIAN FENG Ma, KINOSHITA Toshinori, NAITO Satoshi, YAMAYA Tomoyuki, SHINOZAKI Kazuko, SUGIMOTO Keiko, OKI Taikan, SATAKE Akiko, UMEDA Masaaki, ASHIKARI Motoyuki, KYOZUKA Junko

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)

Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)

Institution: Okayama University

2010/04/01 - 2016/03/31
Analysis of molecular mechanisms controlling shoot branching

KYOZUKA Junko

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)

Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)

Institution: The University of Tokyo

2010/04/01 - 2015/03/31

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Dormancy of the axillary buds and shoot branching in the inflorescence were analyzed at a molecular level. First, an experimental system to analyze the bud dormancy was established. By using this system, it was found that cell divisions were stopped in the whole area of the buds when they go to the dormancy state. On the other hand, cell division restarts when buds start to grow. Microarray analysis using laser dissected buds showed a possibility that ABA, Jasmonic acids and plant specific class of cell cycle inhibitors work downstream of Strigolactonn to control bud dormancy.
Analysis of molecular mechanisms controlling shoot branching

JUNKO Kyozuka

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

Category: Grant-in-Aid for Scientific Research (A)

Institution: The University of Tokyo

2010/04/01 - 2014/03/31

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The number of grains produced per inflorescence is a critical determinant of yield in rice. During inflorescence development, meristems grow as a branch to generate further meristems which each terminates as a grain-producing spikelet. In the dominant gain-of-function mutant taw1-D, a delay in spikelet specification causes prolonged branch formation, resulting in increased grain production. We show that the taw1-D2 allele mediates more than a 40% rise in yield per plant in a commercial rice cultivar. In contrast, reduction of TAW1 activity accelerates spikelet formation resulting in a decrease in grain number. TAW1, encoding a nuclear protein of an unknown function, shows intense expression in panicle branch meristems, which then disappears from incipient spikelet meristems. It appears that TAW1 regulates the panicle architecture through suppression of spikelet meristem identity. We thus propose TAW1 as a novel molecular link between grain number and meristem phase change in rice.
イネ花序形成においてメリステムの相転換を調節する分子機構

経塚淳子

Offer Organization: 日本学術振興会

System: 科学研究費助成事業特定領域研究

Category: 特定領域研究

Institution: 東京大学

2009 - 2010

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本研究では、イネの花序形成においてメリステムの相転換を制御する遺伝子ネットワークに関する知見を得ることを目的とした。シロイヌナズナUFOのオーソログABERRANT PANICLE ORGANIZATION1 (AP01)は、UF0とは逆に、花メリステムへの転換を抑制し(Ikeda et al. 2007)、この効果はAP01発現量に依存する。また、生殖成長転換時に起こるメリステムサイズの急激な増加もAP01に依存する。これらから、AP01が、メリステムでの細胞増殖の制御を介して花メリステムへの相転換を抑制すると考え、解析を進めることにした。今年度は、RCN(イネTFL1)がAP01の下流で働き、メリステムでの細胞増殖を促進することを示した。また、RFL(イネFLORICA/LFY)がAP01と相互作用すること、AP01機能にはRFLが必須であることを確認した。AP01、RFLは生殖成長転換直後にSAM全体で発現を開始する。同様の発現パターンを示す遺伝子群に関する情報を得て、それらの機能解析を開始した。イネの花芽運命決定遺伝子を単離し、これがOsMADS34とよばれるSEPファミリー遺伝子をコードすることを明らかにした。 LOGのSAM先端での発現に必要なシス配列は翻訳開始点より上流5kbまでには存在せず、翻訳開始点と第3イントロンの間に存在することを明らかにした。
植物が周囲の混雑度を感知し、伝えるしくみの解析

経塚淳子

Offer Organization: 日本学術振興会

System: 科学研究費助成事業挑戦的萌芽研究

Category: 挑戦的萌芽研究

Institution: 東京大学

2008 - 2009

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植物は密植されると小さく育ち、逆に、広い場所に1本だけ植えれば大きく育つ。この現象の説明として、密植すると個体間で養分の競合が起こる、あるいは光がさえぎられる、などが挙げられるが、これらの説明に確固とした科学的裏付けがあるわけではない。そこで、植物は何らかの個体間コミュニュケーションの方法を備えており、それを用いて自分が置かれた環境の混雑具合を感知し、その情報に基づき成長程度を制御しているのではないかと考え、予備的解析を開始した。今年度は、腋芽の伸長を制御する新規ホルモンであるストリゴラクトンに関する解析を進めた。特に、分げつが過剰に成長する2つの変異体d14、fc1を解析した。これらの異常はストリゴラクトンにより相補されず、また、変異体でもストリゴラクトンは合成されていた。D14はαβ水酸化酵素スーパーファミリーに属するタンパク質をコードしており、ストリゴラクトンの受容体である可能性が示唆された。FC1遺伝子は2003年にすでに報告されている。本研究では、FC1がストリゴラクトンの下流で働くことを明らかにした。
メリステムの活性維持、相転換におけるサイトカイニンの役割

経塚淳子

Offer Organization: 日本学術振興会

System: 科学研究費助成事業特定領域研究

Category: 特定領域研究

Institution: 東京大学

2008 - 2008

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・APO1はシロイヌナズナUFOのオーソログで、Fボックスタンパク質をコードする(lkeda et. al.2007)。ところが、APO1の機能はUFOやそのオーソログとは逆であり、APO1は花メリステムへの転換を抑制する。劣性apo1変異体、APO1発現量が増加した優性変異体(apo1-D)および過剰発現体の解析から、花メリステムへの転換の抑制がAPO1の発現量に依存することを明らかにした。イネでは、生殖成長期に急激にメリステムのサイズが増加するが、このサイズ増加と細胞数増加程度が、APO1発現量に依存することがわかった。このことから、APO1はメリステムでの細胞増殖に関わる機能を果たすこと、また細胞増殖とメリステムの相転換の関係が示唆された。APO1の下流で働く遺伝子の単離に向けて、誘導型APO1 : GRをイネに導入し、解析に用いる系統を選抜した。・log変異体では胚発生初期からSAMが小さいことを観察し、胚発生時のSAM形成においてサイトカイニンが必要であることを示した。さらに、LOGを構成的に過剰発現すると胚発生時に複数のSAMが分化することを見出した。この現象を詳細に観察したところ、SAM分化が開始する受精後3日目には、過剰発現体と野生型の間で胚の大きさには差はみられないが、過剰発現体ではOSH1(未分化細胞マーカー)発現領域が拡大していた。したがって、サイトカイニンがメリステム形成を直接的に促進するという可能性が示唆された。
Analysis of molecular mechanisms controlling axillary meristem formation and development

KYOZUKA Junko

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: The University of Tokyo

2006 - 2008
腋芽形成を決定するLAXの分子機能の解明

経塚淳子

Offer Organization: 日本学術振興会

System: 科学研究費助成事業特定領域研究

Category: 特定領域研究

Institution: 東京大学

2005 - 2006

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今年度の成果 LAXの細胞非自律的な働き lax変異体では腋生分裂組織が作られないことから、LAXの機能は腋生分裂組織が形成される部位で発揮されると予想されたが、予想に反してLAX mRNAは腋芽の向軸側の境界で層状に発現した。LAXタンパク質の局在を調べたところ、LAXタンパク質の局在はmRNAが観察される領域から腋生分裂組織方向にずれていることがわかった。したがって、LAXタンパク質は方向性を持って細胞間を異動していることが示唆された。茎頂分裂組織の維持に必要なLONELY GUY (LOG)の解析 log変異体では花芽分裂組織が正常に維持されず、花器官数が減少する。また、形成される花芽の数も少なく、小さな穂を形成する。理研植物科学センターの榊原均博士との共同研究により、LOG遺伝子はサイトカイニン合成の最終ステップである、ヌクレオチド型サイトカイニンからのヌクレオチドの離脱を触媒する酵素をコードすることが明らかになった。LOGは茎頂分裂組織の先端部分の非常に限られた領域で発現する。したがって、植物体中では茎頂分裂組織を維持するために局所的にサイトカイニンを活性化する機構が働いていることが示された。将来の展望イネでは、穂に形成される花芽の数は、穂の枝の先端の花序分裂組織が花芽に転換するタイミングによって決まる。今後は、LAXや、LOG遺伝子の機能に関してさらなる解析を行うことにより、サイトカイニンと分裂組織の相転換のかかわりについて新たな知見が得られるものと期待される。
イネ穂の形態を決定する分子機構の解析

経塚淳子

Offer Organization: 日本学術振興会

System: 科学研究費助成事業特定領域研究

Category: 特定領域研究

Institution: 東京大学

2003 - 2004

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私たちが解析しているLAXはイネの腋芽分裂組織形成に必須の遺伝子であり、lax変異体では穂の分枝形成および花芽形成が著しく抑制される。LAX遺伝子はHLHドメインを持つ転写調節因子をコードし、LAX mRNAは腋芽形成時にSAMと腋芽形成予定領域との境界部で層状の発現を示す。今年度の成果 1.LAX遺伝子の解析・分子マーカーを用いたLAX機能の解析 LAXは分裂組織の開始ではなく、維持に関与することが示唆された。・LAXの下流因子の単離マイクロアレイ解析によりLAXにより発現が誘導される遺伝子65個を同定した・LAX2量体パートナーの単離 LAXとヘテロ2量体を形成するbHLH遺伝子を同定した。 2.イネ穂形成時に発現する遺伝子の網羅的解析穂の分枝形成時に発現が変化する遺伝子378個を同定した。穂の発生開始直後には少数の転写因子の発現の上昇が顕著であり、それ以降はさまざまな機能の多数の遺伝子の発現が上昇・下降した。これらの、発現パターンをin situ hybridization法により詳細に解析した。これらの情報は発生や成長に伴う遺伝子発現の変化を解析するための遺伝子マーカーとしても貴重である。興味深いことに、これらのうち2クローン(103、109、ともに転写因子)はLAXとほぼ同じ発現パターンを示した。特に、103遺伝子の発現はlax変異体で消失しLAXの誘導により著しく上昇したことから103はLAXの下流因子であると考えられた。一方、109の発現はlax変異体でもLAX発現誘導によっても変化せず、109はLAXの上流あるいはLAXとは独立に機能していると考えられた。
イネ穂の形態を決定する分子機構の解析

経塚淳子

Offer Organization: 日本学術振興会

System: 科学研究費助成事業特定領域研究

Category: 特定領域研究

Institution: 東京大学

2002 - 2002

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LAX遺伝子の解析これまで穂の分枝形成を決定する遺伝子としてLAXの単離・解析を進めてきた。イネ生殖成長においては、一次枝梗、二次枝梗、側性穎花が新たな分枝、すなわち腋芽(axillary meristem)として形成される。lax変異体ではこれらすべての形成が抑制される。今年度は新たにreduced branching (reb)変異体の解析を開始した。reb変異体では一次枝梗、二次枝梗、側性穎花の数が減少する。また、lax、rebともに栄養成長期の腋芽である分げつ形成は正常であるのに対して、lax reb二重変異体では、分げつも含めて、すべての腋芽形成が抑制された。これらのことから、1)イネの腋芽形成(分げつ形成、穂の枝梗形成、側性穎花形成)はその分化運命に関わらず共通の遺伝的プログラムにより制御されており、2)LAXおよびREBはこの過程に関わる重要な遺伝子であることが明らかになった。 LAX遺伝子の単離は昨年度中に終了していた。今年度はその発現パターンの詳細な解析を行った。この結果から、LAXは腋芽形成にともないSAMと新たな分裂組織形成領域の境界で層状に発現することが明らかになった。また、分げつ形成においても同様のLAX発現パターンが認められた。しかしながら、胚発生時のSAM形成においてはLAX発現は見られなかった。laxreb二重変異体でもSAMは正常に形成される。したがって、腋芽形成は胚発生時のSAM形成とは独立のプログラムにより制御されていると考えられた。
イネ穂の分枝を決定する分子機構の解析

渡辺淳子

Offer Organization: 日本学術振興会

System: 科学研究費助成事業特定領域研究(A)

Category: 特定領域研究(A)

Institution: 奈良先端科学技術大学院大学

2001 - 2001

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LAX遺伝子の単離 719個体を用いた精密マッピングにより、LAX遺伝子座を約80kbの領域に絞り込んだ。強い表現形を示すlax-2アリルではこの領域中に36kb以上の欠失が認められた。36kb中に予想される遺伝子に関してlax-1アリルの塩基配列を決定したところ、そのうちのひとつについてのみ変異が認められたため、これがLAX遺伝子であると考えた。LAXタンパク質は222アミノ酸からなり、bHLHドメインを持つ転写因子であると予想された。また、bHLHドメイン以外には保存された配列は見い出されず、また、シロイヌナズナゲノム中には相同遺伝子が見つからなかった。lax-1アリルでは、ORF中にLTRタイプのレトロトランスポゾン様配列が挿入しており、その結果、148番目のアミノ酸以降に3アミノ酸が挿入され、終止コドンが生じていた。In situハイブリダイゼーション法によりLAXmRNA発現部位を決定した。LAXは茎頂分裂組織と器官分化予定領域の境界で特異的に発現していた。この発現は器官分化の開始にともない消失した。 FZP遺伝子の単離 53個体の変異体の解析により、FZP遺伝子座を第7染色体上の266kbの領域に絞り込んだ。さらに、精密なマッピングを行うために、この266kb領域に12個のdCAPSマーカーを作成した。また、約800個体のF2集団を育成中であり、この集団中のfzp変異個体を精密マッピングに用いる。
イネ穂の分枝を決定する分子機構の解析

経塚淳子

Offer Organization: 日本学術振興会

System: 科学研究費助成事業特定領域研究(A)

Category: 特定領域研究(A)

Institution: 奈良先端科学技術大学院大学

2000 - 2000

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本研究では、イネの分枝パターン決定に主要な役割を果たすと考えられるLAX遺伝子および小花梗形成に必須の遺伝子であるFZP(F__-riz__-zy P__-anicle)を単離する。これら遺伝子の解析は、イネ育種のみではなく、植物の形態形成の基礎研究という観点からも重要である。本年度は以下の成果が得られた。 LAX遺伝子の単離・lax1-2変異体が分離するF2集団を育成した。・169個体の変異体の連鎖解析から、LAX遺伝子が第1染色体長腕部140.2CMと142.2CMの間に存在することが明らかとなった。これらの変異体のうち、140.2CMのマーカーにおいて組み換えが見られるものは9個体、142.2CMのマーカーでは2個体であった。また、141.6CMのマーカーでは組み換え個体は得られなかった。・さらに約500個体の突然変異体を用いた連鎖解析を開始した。・LAX近傍の遺伝子配列情報をもとに、141.6CM周辺のdCAPSマーカーの作成を進めている。 FZP遺伝子の単離・トランスポゾンの挿入により引き起こされたfzp変異体2系統(fzp2-M、fzp2-K)において、ゲノムへの挿入と表現型が完全に連鎖していることを3世代、67個体で確認した。・トウモロコシ由来AC挿入個体(fzp2-M)から、Acフランキング配列を単離した。・fzp2-K系統ではfzp2-MにおいてAcが挿入されている部位から22bp離れた場所に、LINEタイプのレトロトランスポゾンが挿入されていた。・FZP2遺伝子は新規な遺伝子であると予想された。
Analysis of molecular mechanisms involved in the evolution of plant morphology

KYOZUKA Junko

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

Category: Grant-in-Aid for Scientific Research (C)

Institution: NARA INSTITUTE OF SCIENCE AND TECHNOLOGY

1997 - 2000

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The floral morphology of grass species is distinct from typical dicot plants. In order to achieve a better understanding of the molccular basis for this diversion, we isolated RAP1A, RAP1B and RAG, putative rice homologs for the Arabidopsis class A gene APETALA1(AP1) and class C gene AGAMOUS(AG), respectively. Expression patterns of RAP1A.RAG, and OsMADS2, a rice homolog of the class B gene, were analyzed by in situ hybridization. RAP1A mRNA was expressed in the apical region of the floral meristem at an early stage of spikelet development, and then its expression was localized in developing lemma, palea and lodicules. OsMADS2 transcript was first observed in the region where stamen primordia are formed. Soon after, OsMADS2 mRNA appeared in the lodicule primordia as well as stamen primordia and this RNA accumulation pattern persisted till late stages of floral development. The expression of RAG was observed in stamens and pistils of wild type young spikelets. These RNA accumulation patterns are mostly similar to those of Arabidopsis class A, B, C genes supporting the notion that the ABC model may be extended to rice. In order to clarify the evolutionary relationship between grass sterile organs, such as lodicules, the lemma and the palea, and the dicot floral organs, we expressed RAG, a rice (Oryza sativa L.) AGAMOUS(AG) ortholog, in rice plants under the control of an Actin I promoter.As a consequence of the ectopic expression of the RAG, lodicules were homeotically transformed into stamens. In total, the transformation of lodicules to staminoid organs was observed in 18 out of 26 independent transgenic lines. In contrast to the almost complete transformation occurred in lodicules, none of the transgenic plants exhibited any morphological alterations in the palea or the lemma. Our results confirmed the prediction that the lodicule is an equivalent of a dicot petal and that the ABC model can be applied to rice at least for organ specification in lodicules and stamens. On the other hand, the absence of morphological alterations in the palea or the lemma raised the possibility that the simple application of the ABC model to structures outside the lodicules may not be valid.

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