转录因子OsZFN421调控水稻株高的作用机理研究

Plant height is one of the important agronomic traits associated with yield, photosynthetic efficiency and lodging resistance in rice. The first green revolution rose in rice field for the successful cultivation of semidwarf rice. Studies have shown that dwarf mutations are associated with metabolic or signal transduction of gibberellin (GA) and brassinosteroid (BR). With the continuous cloning of dwarfing genes, it has been found there is a complex genetic regulatory network of plant height. There are many questions that remain to be addressed. a new gene named OsZFN421 was found to control plant height. it is a transcription factor. In order to understand Its position in the genetic network of plant height development gene and their interaction regulation, provide the theoretical basis for breeding new plant type rice. We will carry out the following studies. (1) the biological function of OsZFN421;(2) the expression pattern of OsZFN421 in rice;(3) the target of OsZFN421 regulation; (4) the position of OsZFN421 in metabolic or signal transduction of gibberellin (GA) and brassinosteroid (BR). If these question are answered, the genetic network of regulation plant height in rice will be clear. a perfect molecular system in new type plant breeding will be established.

水稻株高是与产量、光合效率和抗倒性密切相关的重要农艺性状。矮秆水稻的培育成功, 引发了全球水稻生产的第一次绿色革命。研究表明矮化突变与赤霉素(GA)和油菜素类固醇(BR)代谢或信号转导有关，随着矮秆基因的不断克隆，发现影响株高调控网络比较复杂，还有很多问题有待研究。本项目通过克隆一个调控株高的转录因子OsZFN421，研究其生物学功能，并阐明其在株高发育基因遗传网络中的位置以及它们的互作调控规律，为水稻株型育种提供理论基础。具体研究内容包括：（1）OsZFN421的生物学功能；（2）OsZFN421在水稻中的表达模式；（3）OsZFN421调控的靶基因；（4）OsZFN421在赤霉素(GA)或油菜素类脂(BR)途径的位置关系。通过项目实施，对影响株高的调控网络有一个更清晰的认识，为水稻新株型育种建立一个更完善分子育种体系。

水稻株高是与产量、光合效率和抗倒性密切相关的重要农艺性状。矮秆水稻的培育成功, 引发了全球水稻生产的第一次绿色革命。本项目研究一个调控株高的半矮秆基因SD12（OsZFN421）的作用机理，sd12与抽穗期的 WT相比，株高降低了约 20 厘米，粒宽减小，千粒重减少，分蘖稍增加，节间缩短，节间细胞数量减少。SD12编码泛素化连接酶E3, UBC32 是SD12的特定 E2， UBC32的靶向敲除，结果导致水稻严重矮化， UBC32定位于细胞质和细胞核 、与SD12共定位于细胞核。SD12 、UBC32在组织中组成型表达。SD12是GA合成途径上的基因，SD12缺乏泛素修饰会影响GAs的生物合成途径，导致sd12中具有生物活性的GAs含量降低，最终导致sd12半矮化。