拟南芥类受体蛋白激酶CRKN1在脱落酸信号转导中的功能研究

Receptor-like kinases (RLKs) have been reported to regulate many developmental and defense process, but only few members have been functionally characterized. Our previous results showed that overexpression of CRKN1, a cysteine-rich receptor-like protein kinase, improve dehydration tolerance of detached leaves. We also found these overexpression lines confer ABA hypersensitivity. So drought resistance very likely depends on the ABA pathway. In order to clarify the mechanism of CRKN1 improving drought resistance and regulating abscisic acid signaling, we plan to study the drought resistance traits and ABA related phenotype of CRKN1 overexpression lines. The researches of subcellular localization of CRKN1 protein and expression profile of CRKN1 gene will be performed. We will, in addition, illustrate how ABA regulate the expression and stability of CRKN1 and assay expression of some ABA-responsive genes in CRKN1-transgenic lines. These results will enrich your perspective on the Receptor-like kinases and ABA signaling. Besides, the study of drought resistance may be helpful to change the water use efficiency properly and enrich drought resistance gene resource in agriculture production.

已有报道证明，类受体蛋白激酶参与调控植物的多种生理发育和抗逆过程，但大部分类受体蛋白激酶的功能尚未知晓。我们通过前期实验发现，高表达富含半胱氨酸的类受体蛋白激酶CRKN1能够提高离体叶片的耐旱性。进一步研究发现，高表达株系对ABA的敏感性增强，因此推测抗旱过程很大可能依赖于ABA途径。为了阐明CRKN1基因的抗旱机理以及在ABA信号通路中的功能。我们计划研究CRKN1高表达株系的抗旱性状和ABA相关表型；CRKN1蛋白在植物体内的分布和激酶活性；ABA如何调控CRKN1的转录和蛋白稳定性；CRKN1对下游ABA响应基因的调控。这些研究能够丰富人们对类受体蛋白激酶以及复杂ABA信号转导通路的认识。另外，通过对CRKN1高表达株系抗旱性状和机理的研究，为农业生长中有目的的改变作物的水分利用提供了理论基础和抗旱基因资源。

受体蛋白激酶（receptor like kinases, RLKs）广泛参与植物的生长发育及抗逆过程，但仅有少量成员的功能被研究清楚。通过本项目，我们鉴定了两个定位于细胞膜上的受体蛋白激酶CRKN1和GRACE，并发现其参与了ABA信号转导和植物发育过程。过表达CRKN1的植株会在种子萌发和幼苗生长方面增强对ABA的敏感性，并且会增强植株的抗旱性。磷酸化组学和免疫共沉淀的结果显示，CRKN1可能是通过可逆磷酸化来调控诸多信号转导过程，包括ABA信号转导途径。我们也发现了GRACE负调控种子萌发过程，正调控细胞膨大过程。这些研究将有助于理解复杂的ABA信号通路和植物发育调控通路。