拟南芥PPR蛋白SOAR1调控种子萌发的机制研究

我们在对拟南芥脱落酸受体ABAR的研究中，利用正向遗传学技术，筛选到了ABAR抑制子突变体soar1-1D，分子检测表明SOAR1编码一个PPR蛋白。进一步证据表明SOAR1是细胞质和细胞核中双重定位，并且是作用于ABAR下游、ABI5上游、参与ABA信号调控的种子萌发和幼苗生长过程的核心负调节子。赤霉素和脱落酸拮抗作用会影响种子萌发，因此我们初步研究SOAR1在赤霉素上的表型，发现SOAR1参与了赤霉素信号转导。那么SOAR1是如何调控两种激素信号转导过程，进而影响种子萌发？结合我们目前初步的研究进展，即一是酵母双杂交筛选得到SOAR1互作分子DELLA蛋白，二是通过SOAR1突变体转录本测序获得的两种激素信号转导重要调节子转录水平变化的证据，我们拟通过本项目的研究方案，揭示SOAR1在两种激素信号所调控的种子萌发过程中的作用。

To investigate the mechanism of ABA receptor ABAR mediating ABA signaling in Arabidopsis, we used forward genetical method to screen suppressors of ABAR-overexpressors from the population of the ABAR-overexpression lines and got a mutant named soar1-1D. SOAR1 is a cytosol-nucleus dual-localized pentatricopeptide repeat (PPR) protein, which regualtes seed germiantion and seedling growth and funcions downstream of ABAR and upstream of ABI5. Previous evidence shows that GA and ABA could affect seed germination.So we explore the function of SOAR1 in GA signaling and find it participate in GA signal transduction. How does SOAR1 affect seed germination by regulating ABA and GA signal transduction? Combined the known evidence, which is from the results of Yeast Two Hybrid and RNA sequencing, we plan to illustrate the function of SOAR1 mediating ABA and GA signaling during seed germination. These results will be helpful to elucidate the versitile functions of PPR proteins and make a new guide for the research of hormonal crosstalk.