Elsevier BV Acta Medica Okayama 1674-2052 18 10 2025 The OsATG8–OsATG1–SPIN6 module: Linking nutrient sensing to OsRac1-mediated rice immunity via autophagy-independent mechanisms 1623 1625 EN Yanjun Kou State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute Yoji Kawano Institute of Plant Science and Resources, Okayama University No potential conflict of interest relevant to this article was reported.

MDPI AG Acta Medica Okayama 1422-0067 26 10 2025 Stem Cell Factors BAM1 and WOX1 Suppressing Longitudinal Cell Division of Margin Cells Evoked by Low-Concentration Auxin in Young Cotyledon of Arabidopsis 4724 EN Yuli Jiang Institute for Translational Brain Reaearch, Fudan University Jian Liang Center for Excellence in Molecular Plant Science, Chinese Academy of Sciences Chunyan Wang Center for Excellence in Molecular Plant Science, Chinese Academy of Sciences Li Tan Center for Excellence in Molecular Plant Science, Chinese Academy of Sciences Yoji Kawano Institute of Plant Science and Resources, Okayama University Shingo Nagawa Center for Excellence in Molecular Plant Science, Chinese Academy of Sciences Highly differentiated tissues and organs play essential biological functions in multicellular organisms. Coordination of organ developmental process with tissue differentiation is necessary to achieve proper development of mature organs, but mechanisms for such coordination are not well understood. We used cotyledon margin cells from Arabidopsis plant as a new model system to investigate cell elongation and cell division during organ growth and found that margin cells endured a developmental phase transition from the �gelongation�h phase to the �gelongation and division�h phase at the early stage in germinating seedlings. We also discovered that the stem cell factors BARELY ANY MERISTEM 1 (BAM1) and WUSCHEL-related homeobox1 (WOX1) are involved in the regulation of margin cell developmental phase transition. Furthermore, exogenous auxin treatment (1 nanomolar,nM) promotes cell division, especially longitudinal cell division. This promotion of cell division did not occur in bam1 and wox1 mutants. Based on these findings, we hypothesized a new �gmoderate auxin concentration�h model which emphasizes that a moderate auxin concentration is the key to triggering the developmental transition of meristematic cells. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 2095-9273 70 5 2025 A PRA-Rab trafficking machinery modulates NLR immune receptor plasma membrane microdomain anchoring and blast resistance in rice 733 747 EN Di Liang CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences Dongyong Yang CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences Tai Li Yunnan Key Laboratory of Cell Metabolism and Diseases, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Center for Life Sciences, School of Life Sciences, Yunnan University Zhe Zhu Yunnan Key Laboratory of Cell Metabolism and Diseases, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Center for Life Sciences, School of Life Sciences, Yunnan University Bingxiao Yan CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences Yang He CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences Xiaoyuan Li School of Life Science and Technology, ShanghaiTech University Keran Zhai CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences Jiyun Liu CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences Yoji Kawano Institute of Plant Science and Resources, Okayama University Yiwen Deng CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences Xu Na Wu Yunnan Key Laboratory of Cell Metabolism and Diseases, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Center for Life Sciences, School of Life Sciences, Yunnan University Junzhong Liu Yunnan Key Laboratory of Cell Metabolism and Diseases, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Center for Life Sciences, School of Life Sciences, Yunnan University Zuhua He CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences Nucleotide-binding leucine-rich repeat (NLR) receptors mediate pathogen effector-triggered immunity (ETI) in plants, and a subclass of NLRs are hypothesized to function at the plasma membrane (PM). However, how NLR traffic and PM delivery are regulated during immune responses remains largely unknown. The rice NLR PigmR confers broad-spectrum resistance to the blast fungus Magnaporthe oryzae. Here, we report that a PRA (Prenylated Rab acceptor) protein, PIBP4 (PigmR-INTERACTING and BLAST RESISTANCE PROTEIN 4), interacts with both PigmR and the active form of the Rab GTPase, OsRab5a, thereby loads a portion of PigmR on trafficking vesicles that target to PM microdomains. Microdomain-localized PigmR interacts with and activates the small GTPase OsRac1, which triggers reactive oxygen species signaling and hypersensitive response, leading to immune responses against blast infection. Thus, our study discovers a previously unknown mechanism that deploys a PRA-Rab protein delivering hub to ensure ETI, linking the membrane trafficking machinery with NLR function and immune activation in plants. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 1674-2052 15 12 2022 Improving disease resistance to rice false smut without yield penalty by manipulating the expression of effector target 1834 1837 EN Qiong Wang School of Plant Protection, Yangzhou University Yoji Kawano Institute of Plant Science and Resources, Okayama University No potential conflict of interest relevant to this article was reported.

Oxford University Press (OUP) Acta Medica Okayama 0022-0957 74 3 2022 The secreted immune response peptide 1 functions as a phytocytokine in rice immunity 1059 1073 EN Pingyu Wang Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University Huimin Jia Shanghai Center for Plant Stress Biology and Center of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences Ting Guo Shanghai Center for Plant Stress Biology and Center of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences Yuanyuan Zhang Shanghai Center for Plant Stress Biology and Center of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences Wanqing Wang Institute of Plant Science and Resources, Okayama University Hideki Nishimura Institute of Plant Science and Resources, Okayama University Zhengguo Li Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University Yoji Kawano Shanghai Center for Plant Stress Biology and Center of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences Small signalling peptides play important roles in various plant processes, but information regarding their involvement in plant immunity is limited. We previously identified a novel small secreted protein in rice, called immune response peptide 1 (IRP1). Here, we studied the function of IRP1 in rice immunity. Rice plants overexpressing IRP1 enhanced resistance to the virulent rice blast fungus. Application of synthetic IRP1 to rice suspension cells triggered the expression of IRP1 itself and the defence gene phenylalanine ammonia-lyase 1 (PAL1). RNA-seq results revealed that 84% of genes up-regulated by IRP1, including 13 OsWRKY transcription factors, were also induced by a microbe-associated molecular pattern (MAMP), chitin, indicating that IRP1 and chitin share a similar signalling pathway. Co-treatment with chitin and IRP1 elevated the expression level of PAL1 and OsWRKYs in an additive manner. The increased chitin concentration arrested the induction of IRP1 and PAL1 expression by IRP1, but did not affect IRP1-triggered mitogen-activated protein kinases (MAPKs) activation. Collectively, our findings indicate that IRP1 functions as a phytocytokine in rice immunity regulating MAPKs and OsWRKYs that can amplify chitin and other signalling pathways, and provide new insights into how MAMPs and phytocytokines cooperatively regulate rice immunity. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 0140-7791 45 2022 Three highly conserved hydrophobic residues in the predicted ƒ¿2�]helix of rice NLR protein Pit contribute to its localization and immune induction 1876 1890 EN Qiong Wang School of Horticulture and Plant Protection Yangzhou University Yangzhou China Yuying Li CAS Center for Excellence in Molecular Plant Sciences, Shanghai Center for Plant Stress Biology Chinese Academy of Sciences Shanghai China Ken�]ichi Kosami CAS Center for Excellence in Molecular Plant Sciences, Shanghai Center for Plant Stress Biology Chinese Academy of Sciences Shanghai China Chaochao Liu School of Biotechnology Jiangsu University of Science and Technology Zhenjiang China Jing Li CAS Center for Excellence in Molecular Plant Sciences, Shanghai Center for Plant Stress Biology Chinese Academy of Sciences Shanghai China Dan Zhang School of Horticulture and Plant Protection Yangzhou University Yangzhou China Daisuke Miki CAS Center for Excellence in Molecular Plant Sciences, Shanghai Center for Plant Stress Biology Chinese Academy of Sciences Shanghai China Yoji Kawano Institute of Plant Science and Resources, Okayama University Nucleotide-binding leucine-rich repeat (NLR) proteins work as crucial intracellular immune receptors. N-terminal domains of NLRs fall into two groups, coiled-coil (CC) and Toll-interleukin 1 receptor domains, which play critical roles in signal transduction and disease resistance. However, the activation mechanisms of NLRs, and how their N-termini function in immune induction, remain largely unknown. Here, we revealed that the CC domain of a rice NLR Pit contributes to self-association. The Pit CC domain possesses three conserved hydrophobic residues that are known to be involved in oligomer formation in two NLRs, barley MLA10 and Arabidopsis RPM1. Interestingly, the function of these residues in Pit differs from that in MLA10 and RPM1. Although three hydrophobic residues are important for Pit-induced disease resistance against rice blast fungus, they do not participate in self-association or binding to downstream signalling molecules. By homology modelling of Pit using the Arabidopsis ZAR1 structure, we tried to clarify the role of three conserved hydrophobic residues and found that they are located in the predicted ƒ¿2-helix of the Pit CC domain and involved in the plasma membrane localization. Our findings provide novel insights for understanding the mechanisms of NLR activation as well as the relationship between subcellular localization and immune induction. No potential conflict of interest relevant to this article was reported.

Oxford University Press (OUP) Acta Medica Okayama 0032-0781 62 11 2021 The Small GTPase OsRac1 Forms Two Distinct Immune Receptor Complexes Containing the PRR OsCERK1 and the NLR Pit 1662 1675 EN Akira Akamatsu Department of Biosciences, Kwansei Gakuin University Masayuki Fujiwara Graduate School of Biological Sciences, Nara Institute of Science and Technology Satoshi Hamada Graduate School of Biological Sciences, Nara Institute of Science and Technology Megumi Wakabayashi Graduate School of Biological Sciences, Nara Institute of Science and Technology Ai Yao Graduate School of Biological Sciences, Nara Institute of Science and Technology Qiong Wang Department of Horticulture and Plant Protection Ken-ichi Kosami CAS Center for Excellence in Molecular Plant Sciences, Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences Thu Thi Dang Graduate School of Biological Sciences, Nara Institute of Science and Technology Takako Kaneko-Kawano College of Pharmaceutical Sciences, Ritsumeikan University Fumi Fukada Institute of Plant Science and Resources Ko Shimamoto Graduate School of Biological Sciences, Nara Institute of Science and Technology Yoji Kawano Institute of Plant Science and Resources, Okayama University Plants employ two different types of immune receptors, cell surface pattern recognition receptors (PRRs) and intracellular nucleotide-binding and leucine-rich repeat-containing proteins (NLRs), to cope with pathogen invasion. Both immune receptors often share similar downstream components and responses but it remains unknown whether a PRR and an NLR assemble into the same protein complex or two distinct receptor complexes. We have previously found that the small GTPase OsRac1 plays key roles in the signaling of OsCERK1, a PRR for fungal chitin, and of Pit, an NLR for rice blast fungus, and associates directly and indirectly with both of these immune receptors. In this study, using biochemical and bioimaging approaches, we revealed that OsRac1 formed two distinct receptor complexes with OsCERK1 and with Pit. Supporting this result, OsCERK1 and Pit utilized different transport systems for anchorage to the plasma membrane (PM). Activation of OsCERK1 and Pit led to OsRac1 activation and, concomitantly, OsRac1 shifted from a small to a large protein complex fraction. We also found that the chaperone Hsp90 contributed to the proper transport of Pit to the PM and the immune induction of Pit. These findings illuminate how the PRR OsCERK1 and the NLR Pit orchestrate rice immunity through the small GTPase OsRac1. No potential conflict of interest relevant to this article was reported.

Nature Portfolio Acta Medica Okayama 2045-2322 11 1 2021 NB-LRR-encoding genes conferring susceptibility to organophosphate pesticides in sorghum 19828 EN Zihuan Jing Institute of Plant Science and Resources, Okayama University Fiona W. Wacera Institute of Plant Science and Resources, Okayama University Tsuneaki Takami Institute of Plant Science and Resources, Okayama University Hideki Takanashi Graduate School of Agricultural and Life Sciences, The University of Tokyo Fumi Fukada Institute of Plant Science and Resources, Okayama University Yoji Kawano Institute of Plant Science and Resources, Okayama University Hiromi Kajiya-Kanegae Research Center for Agricultural Information Technology, National Agriculture and Food Research Organization Hiroyoshi Iwata Graduate School of Agricultural and Life Sciences, The University of Tokyo Nobuhiro Tsutsumi Graduate School of Agricultural and Life Sciences, The University of Tokyo Wataru Sakamoto Institute of Plant Science and Resources, Okayama University Organophosphate is the commonly used pesticide to control pest outbreak, such as those by aphids in many crops. Despite its wide use, however, necrotic lesion and/or cell death following the application of organophosphate pesticides has been reported to occur in several species. To understand this phenomenon, called organophosphate pesticide sensitivity (OPS) in sorghum, we conducted QTL analysis in a recombinant inbred line derived from the Japanese cultivar NOG, which exhibits OPS. Mapping OPS in this population identified a prominent QTL on chromosome 5, which corresponded to Organophosphate-Sensitive Reaction (OSR) reported previously in other mapping populations. The OSR locus included a cluster of three genes potentially encoding nucleotide-binding leucine-rich repeat (NB-LRR, NLR) proteins, among which NLR-C was considered to be responsible for OPS in a dominant fashion. NLR-C was functional in NOG, whereas the other resistant parent, BTx623, had a null mutation caused by the deletion of promoter sequences. Our finding of OSR as a dominant trait is important not only in understanding the diversified role of NB-LRR proteins in cereals but also in securing sorghum breeding free from OPS. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 1467-7644 18 2 2019 Identification of endogenous small peptides involved in rice immunity through transcriptomics- and proteomics-based screening 415 428 EN Pingyu Wang Shanghai Center for Plant Stress Biology, Center of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences Shaolun Yao Shanghai Center for Plant Stress Biology, Center of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences Ken-ichi Kosami Shanghai Center for Plant Stress Biology, Center of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences Ting Guo Shanghai Center for Plant Stress Biology, Center of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences Jing Li Shanghai Center for Plant Stress Biology, Center of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences Yuanyuan Zhang Shanghai Center for Plant Stress Biology, Center of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences Yoichiro Fukao Department of Bioinformatics, Ritsumeikan University Takako Kaneko-Kawano College of Pharmaceutical Sciences, Ritsumeikan University Heng Zhang Shanghai Center for Plant Stress Biology, Center of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences Yi-Min She Shanghai Center for Plant Stress Biology, Center of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences Pengcheng Wang Shanghai Center for Plant Stress Biology, Center of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences Weiman Xing Biomolecular Structure and Design, Shanghai Center for Plant Stress Biology Kousuke Hanada Department of Bioscience and Bioinformatics, Kyushu Institute of Technology Renyi Liu Center for Agroforestry Mega Data Science and FAFU-UCR Joint Center for Horticultural Biology and Metabolomics, Haixia Institute of Science and Technology,Fujian Agriculture and Forestry University Yoji Kawano Institute of Plant Science and Resources, Okayama University Small signalling peptides, generated from larger protein precursors, are important components to orchestrate various plant processes such as development and immune responses. However, small signalling peptides involved in plant immunity remain largely unknown. Here, we developed a pipeline using transcriptomics- and proteomics-based screening to identify putative precursors of small signalling peptides: small secreted proteins (SSPs) in rice, induced by rice blast fungus Magnaporthe oryzae and its elicitor, chitin. We identified 236 SSPs including members of two known small signalling peptide families, namely rapid alkalinization factors and phytosulfokines, as well as many other protein families that are known to be involved in immunity, such as proteinase inhibitors and pathogenesis-related protein families. We also isolated 52 unannotated SSPs and among them, we found one gene which we named immune response peptide (IRP) that appeared to encode the precursor of a small signalling peptide regulating rice immunity. In rice suspension cells, the expression of IRP was induced by bacterial peptidoglycan and fungal chitin. Overexpression of IRP enhanced the expression of a defence gene, PAL1 and induced the activation of the MAPKs in rice suspension cells. Moreover, the IRP protein level increased in suspension cell medium after chitin treatment. Collectively, we established a simple and efficient pipeline to discover SSP candidates that probably play important roles in rice immunity and identified 52 unannotated SSPs that may be useful for further elucidation of rice immunity. Our method can be applied to identify SSPs that are involved not only in immunity but also in other plant functions. No potential conflict of interest relevant to this article was reported.