水稻OsSGS3与OsHEN1调控small RNAs合成及其对抗病性的调节

植物免疫受small RNAs的广泛调控，但在模式作物水稻中如何调控small RNAs介导的抗病性还没有深入研究。本实验室前期工作发现SGS3参与逆境响应的siRNAs合成和记忆。在水稻中发现OsSGS3与OsHEN1 RNAi的株系具有广谱抗病性。两者在siRNA合成上具有上下游关系，而OsHEN1还参与了miRNAs的合成。本项目将在此基础上，进一步研究OsSGS3与OsHEN1调控small RNAs合成途径及其对水稻抗病性的调节。研究内容包括：（1）剖析OsSGS3与OsHEN1蛋白参与调控的小RNA途径；（2）揭示OsSGS3和OsHEN1调节水稻抗病性的分子机制；（3）建立一个以OsHEN1-siRNAs/miRNAs为主干的水稻广谱抗病的信号网络。本项目的开展将有助于建立新的水稻广谱抗病研究体系，有助于发掘新的抗病靶点，且具有重要的抗病分子育种的应用潜力。

Small RNAs are big contributors to plant immunity, however, how small RNAs are regulated in plant disease resistance is still largely unknown in rice. Previoulsy, SGS3 has been found to be involved in the biogenesis of siRNAs and the memory of stress responses in Arabidopsis. Both OsSGS3 and OsHEN1 RNAi plants showed broad-spectrum disease resistance. It’s known that OsHEN1 acts upstream of OsSGS3 in the biosynthesis of siRNAs. Besides, OsHEN1 regulates miRNAs biogenesis as well. To elucidate the mechanism of OsSGS3 and OsHEN1-mediated immunity and to identify its interaction parterners, here in this program, we will further focus on the following aspects to expolore how OsSGS3 and OsHEN1 regulate small RNAs biogenesis and disease resistance in rice; and study (1) the small RNA pathways regulated by OsSGS3 and OsHEN1; (2) the molecular mechanism of OsSGS3 and OsHEN1 in regulation of disease resistance in rice; (3) the signal network of broad-spectrum disease resistance mediated by OsHEN1 and siRNAs/miRNAs . This study will provide clues for our understanding of how small RNAs involved in the broad resistance of plant against pathogens, expect to establish a new broad-spectrum resistant rice research system, identify new targets of disease resistance, and finally benefit the moluculr breeading in agriculture.