HSFA1家族转录因子在植物热激形态建成中的作用机理研究

升高的环境温度会诱导植物会产生两种不同的响应：以PIF4为核心转录因子的高温形态建成（约28度）和以HSFA1s为核心转录因子的热激响应（37度以上）。 目前植物高温研究领域一般都把这两种高温响应当成两个不同的生物学过程，分开进行研究。申请人前期通过RNAseq发现：28度高温处理20分钟以上能够诱导HSFA1s下游靶基因的表达； HSFA1s表达缺失突变体hsfa1-cq对28度诱导的下胚轴伸长完全不敏感；28度时hsfa1-cq中PIF4的表达水平也远远低于野生型，说明HSFA1s可能也在植物高温形态建成过程中发挥重要调节作用。本项目将综合利用分子生物学、遗传学和蛋白质组学研究方法，深入探究HSFA1s在调节植物高温形态建成中的作用和作用的分子机理。我们的研究结果将揭示一个在28度和37度高温条件下植物中保守的响应机制，刷新我们对植物感受和应对环境高温的认识，具有非常重要的科学意义。

When the environmental temperature rises above the optimum growth temperature, it will induce two different thermos-responses in plants: a thermomorphogenesis response (generally around 28 degree for Arabidopsis) governed by the PIF4 family transcription factors, and a heat shock response (generally around 37 degree or higher) governed by HSFA1s family transcription factors. In the current field of plant thermos-responsive study, these two responses are generally treated as two different biological processes, and are studied separated from each other accordingly. Our preliminary RNAseq data showed that treating plants with 28 degree for 20 min is enough to induce the expression of a number of HSFA1s downstream targets. Additionally, we have shown that the hsfa1-cq quadruple mutant, in which the expression of all HSFA1s family transcription factors are knocked out, is completely insensitive to 28 degree induced hypocotyl elongation; and the 28 degree induced expression of PIF4 is also greatly reduced in the hsfa1-cq mutant. Together, these results suggest that HSFA1s family transcription factors might play critical roles in regulating plant thermos-morphogenesis process. In this proposed study, we plan to use a combination of proteomic, molecular biology and genetic methods to decode the molecular mechanism by which HSFA1s regulating plant thermo-morphogenesis process. Our study will reveal a conserved plant thermo-responsive mechanism no matter if the plants encounter a 28 degree or a 37 degree high temperature, and bring new insight into our understanding about the molecular mechanism by which plant sense and respond to raised environmental temperature, which should be a milestone in the field.