title: Jasmonic acid regulates spikelet development in rice.
abstract: The spikelet is the basal unit of inflorescence in grasses, and its formation is crucial for reproductive success and cereal yield. Here, we report a previously unknown role of the plant hormone jasmonic acid (JA) in determining rice (Oryza sativa) spikelet morphogenesis. The extra glume 1 (eg1) and eg2 mutants exhibit altered spikelet morphology with changed floral organ identity and number, as well as defective floral meristem determinacy. We show that EG1 is a plastid-targeted lipase that participates in JA biosynthesis, and EG2/OsJAZ1 is a JA signalling repressor that interacts with a putative JA receptor, OsCOI1b, to trigger OsJAZ1's degradation during spikelet development. OsJAZ1 also interacts with OsMYC2, a transcription factor in the JA signalling pathway, and represses OsMYC2's role in activating OsMADS1, an E-class gene crucial to the spikelet development. This work discovers a key regulatory mechanism of grass spikelet development and suggests that the role of JA in reproduction has diversified during the flowering plant evolution.
authors.affiliation: 1] State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China [2].
authors.forename: Qiang
authors.initials: Q
authors.lastname: Cai
authors.affiliation: 1] State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China [2].
authors.forename: Zheng
authors.initials: Z
authors.lastname: Yuan
authors.affiliation: State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Mingjiao
authors.initials: M
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Changsong
authors.initials: C
authors.lastname: Yin
authors.affiliation: State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Zhijing
authors.initials: Z
authors.lastname: Luo
authors.affiliation: Jiangsu Key Laboratory for Eco-Agricultural Biotechnology around Hongze Lake, Huaiyin Normal University, Huian, Jiangsu, 223300, China.
authors.forename: Xiangxiang
authors.initials: X
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Wanqi
authors.initials: W
authors.lastname: Liang
authors.affiliation: Department of Energy Plant Research Laboratory, Michigan State University, East Lansing Michigan, 48824, USA.
authors.forename: Jianping
authors.initials: J
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Dabing
authors.initials: D
authors.lastname: Zhang
mesh_terms: D001483:Base Sequence; D003517:Cyclopentanes / Q000378:metabolism / Q000494:pharmacology*; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D015151:Immunoblotting; D017403:In Situ Hybridization; D056626:Inflorescence / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D009154:Mutation; D012275:Oryza / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D054883:Oxylipins / Q000378:metabolism / Q000494:pharmacology*; D063245:Plant Development / Q000187:drug effects / Q000235:genetics; D010937:Plant Growth Regulators / Q000378:metabolism / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D011485:Protein Binding; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020798:Two-Hybrid System Techniques
chemical_list: D003517:Cyclopentanes; D054883:Oxylipins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D049452:Green Fluorescent Proteins; C011006:jasmonic acid