Jasmonic acid regulates spikelet development in rice
Jasmonic acid regulates spikelet development in rice
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茉莉酸调节水稻小穗发育
DOI：
10.1038/ncomms4476
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发表时间：
2014-03-01
影响因子：
16.6
通讯作者：
Zhang, Dabing
中科院分区：
文献类型：
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作者：
Cai, Qiang;Yuan, Zheng;Zhang, Dabing
小穗是禾本科植物花序的基本单位，其形成对于繁殖成功和谷物产量至关重要。在此，我们报道了植物激素茉莉酸（JA）在决定水稻（Oryza sativa）小穗形态发生方面此前未知的作用。额外颖壳1（eg1）和eg2突变体表现出小穗形态改变，花器官的特性和数量发生变化，以及花分生组织决定性存在缺陷。我们表明EG1是一种定位于质体的脂肪酶，参与茉莉酸的生物合成，而EG2/OsJAZ1是一种茉莉酸信号转导抑制因子，它与一种假定的茉莉酸受体OsCOI1b相互作用，在小穗发育过程中引发OsJAZ1的降解。OsJAZ1还与OsMYC2（茉莉酸信号通路中的一种转录因子）相互作用，并抑制OsMYC2在激活OsMADS1（一种对小穗发育至关重要的E类基因）中的作用。这项工作揭示了禾本科植物小穗发育的一个关键调控机制，并表明茉莉酸在繁殖中的作用在开花植物进化过程中已经多样化。
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. Theextra glume 1(eg1) andeg2mutants 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 activatingOsMADS1, 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.