Analysis of the function of brassinosteroid on rice growth regulation

油菜素内酯对水稻生长的调节作用分析

基本信息

批准号：
19688001
负责人：
SAKAMOTO Tomoaki
金额：
$ 16.31万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Young Scientists (A)
财政年份：
2007
资助国家：
日本
起止时间：
2007 至 2009
项目状态：
已结题

项目摘要

The major achievement of this research is the finding that weak d2 mutations have probably been used in breeding programs that generated high-yielding cultivars. I also found an interesting phenomenon, namely that the genetic background controls the phenotypes of rice brassinosteroid-related mutants. I obtained some evidence that an insertion of mPing in the promoter of the brassinosteroid receptor gene, OsBRI1, causes this phenomenon. When I performed comprehensive gene-expression analyses of the brassinosteroid-related genes to identify the phenotype-controlling factor mentioned above, I found that auxin treatment transiently increases OsBRI1 expression. This result led to a striking finding: the auxin signal-transcription factor ARF controls the degree of brassinosteroid perception required for normal plant growth and development. I also found evidence of evolution of the genes for CYP734As, which acquired novel functions in brassinosteroid inactivation after the differentiation of monocot and dicot plants, and then increased in number in the rice genome. These genes are directly applicable for regulating the endogenous bioactive brassinosteroid content, and therefore for controlling rice developmental and physiological processes. I have isolated and characterized a novel brassinosteroid-signaling component, ELF1. This research led to an unexpected finding, namely that brassinosteroid and jasmonate signaling compete for the nuclear protein EIZ1. Although further analyses are needed, this will be a productive starting point from which to understand the extensive crosstalk between brassinosteroids and jasmonate, especially in terms of the mechanisms responsible for how plants acquire stress tolerance after brassinosteroid treatment.

这项研究的主要成就是发现弱 d2 突变可能已用于产生高产品种的育种计划。我还发现了一个有趣的现象，即遗传背景控制着水稻油菜素类固醇相关突变体的表型。我获得了一些证据，表明 mPing 插入油菜素类固醇受体基因 OsBRI1 的启动子中会导致这种现象。当我对油菜素类固醇相关基因进行全面的基因表达分析以确定上述表型控制因子时，我发现生长素处理会暂时增加 OsBRI1 的表达。这一结果带来了一个惊人的发现：生长素信号转录因子 ARF 控制正常植物生长和发育所需的油菜素类固醇感知程度。我还发现了 CYP734As 基因进化的证据，该基因在单子叶植物和双子叶植物分化后获得了油菜素类固醇失活的新功能，然后在水稻基因组中的数量增加。这些基因可直接用于调节内源生物活性油菜素类固醇含量，从而控制水稻发育和生理过程。我分离并鉴定了一种新型油菜素类固醇信号成分 ELF1。这项研究带来了一个意想不到的发现，即油菜素类固醇和茉莉酸信号传导竞争核蛋白EIZ1。尽管还需要进一步分析，但这将是了解油菜素类固醇和茉莉酸之间广泛串扰的富有成效的起点，特别是在植物在油菜素类固醇处理后如何获得胁迫耐受性的机制方面。