转录因子OsGATA16调控水稻耐冷的分子机制研究

Low temperature damage is one of the most important factors limiting rice production and planting range. In order to guarantee the high and stable rice yield in high-latitude areas, it is of great significance to carry out research on cold-tolerant mechanism, dig out cold-tolerant genes and breed cold-tolerant rice varieties. OsGATA16, a transcription factor of GATA family, was obtained by screening the cold tolerance of transgenic rice library with overexpression of transcription factors previously. Overexpression of OsGATA16 in rice can significantly improve the cold tolerance of rice seedling. OsGATA16 is a typical transcription factor located in the nucleus. It can be significantly induced by cold stress at the transcription level, and transcriptional activity analysis shows that OsGATA16 has transcriptional inhibition activity. Therefore, this application intends to conduct in-depth functional studies on OsGATA16 on the basis of previous studies. We intend to identify the downstream regulatory genes of OsGATA16 through RNA-seq combined with ChIP-seq analysis, and identify OsGATA16 interacting proteins by yeast two hybridization and immunoprecipitation-mass spectrometry (IP-MS). Through the above studies, the regulation network of OsGATA16 in response to low temperature stress in rice was analyzed, which can also provide new ideas and new materials for rice low temperature tolerance breeding.

低温冷害是限制水稻生产及种植范围的重要因素之一，挖掘水稻耐冷基因，开展水稻耐冷机制研究，培育耐冷水稻品种对于确保高纬度地区的水稻高产稳产具有重要意义。本实验室前期通过对转录因子过量表达转基因水稻文库耐冷性筛选，获得了一个GATA家族转录因子OsGATA16，水稻中过量表达OsGATA16可以显著提高水稻苗期耐冷性。OsGATA16是定位于细胞核，在转录水平受到冷胁迫显著诱导，转录活性分析发现其具有转录抑制活性。本申请拟在已有研究基础上，深入开展OsGATA16功能研究，通过RNA-seq和ChIP-seq分析鉴定OsGATA16的下游调控基因，同时利用酵母双杂交和免疫共沉淀-质谱技术（IP-MS）筛选OsGATA16互作蛋白。通过以上研究，解析OsGATA16在水稻低温胁迫应答中的调控网络，为水稻耐低温育种提供新思路和新材料。

低温冷害是限制水稻生产及种植范围的重要因素之一，挖掘水稻耐冷基因，开展水稻耐冷机制研究，培育耐冷水稻品种对于确保高纬度地区的水稻高产稳产具有重要意义。本项目前期通过对转录因子过量表达转基因水稻文库耐冷性筛选，获得了一个GATA家族转录因子OsGATA16，水稻中过量表达OsGATA16可以显著提高水稻苗期耐冷性。OsGATA16定位于细胞核，在转录水平受到冷胁迫显著诱导，转录活性分析发现其具有转录抑制活性，并且能够抑制OsWRKY45表达。本项目通过对OsGATA16过量表达转基因水稻株系开展转录组学分析，系统筛选了OsGATA16下游调控基因及信号通路，发现OsGATA16过表达株系上调基因中显著富集了参与非生物逆境调控的转录因子，而下调基因中显著富集了生物逆境响应基因；通过对OsGATA16基因开展单倍型分析，发现在启动子、UTR、内含子以及外显子区域共有11个SNP，可以划分为5个单倍型，其中第2种和第3种单倍型中主要是籼稻品种，第1、4、5种单倍型基本上是由粳稻组成，而且单倍型2和3的耐冷性显著低于单倍型1、4和5，进一步挑选了粳稻和籼稻各8个品种在苗期进行冷处理，发现OsGATA16在粳稻中的表达量显著高于籼稻品种；通过酵母双杂交筛选到1个互作蛋白OsVOZ1，已被报道参与调控水稻稻瘟病抗性。因此，OsGATA16可能参与了水稻非生物逆境和生物逆境抗性之间的平衡。下一步对OsGATA16的单倍型进行更深入的功能分析，挖掘优异单倍型，可应用于水稻耐逆分子育种改良。