受体激酶SERKs调控拟南芥根表皮细胞命运决定的分子机理

Somatic embryogenesis receptor-like kinases (SERKs) function as co-receptors in various plant cell signaling processes controlling development and defense. Reverse genetics was employed to investigate the functions of SERKs. A triple mutant, serk1 serk2 bak1, exhibits a shorter root phenotype with exaggerated root hairs compared to wild type. GL2, a marker gene labeling non-hair cells in the epidermis of wild-type roots, shows irregular expression pattern in the bak1 single mutant, resembling the phenotype of a scm mutant. Physical interaction between SCM and SERKs has been detected by a yeast-two-hybrid assay. Based on the preliminary results, we propose to test whether SERKs form a protein complex with SCM to mediate root epidermal cell fate determination, to screen and characterize downstream components involved in SERKs-SCM mediated root epidermal cell differentiation, and to elucidate the early signaling events regulating root epidermal cell fate determination in Arabidopsis.

体细胞胚胎发生类受体激酶SERKs是近年来植物受体激酶研究领域的一组热点蛋白，它们作为共受体参与植物的生长发育和免疫反应等诸多过程。我们在通过反向遗传学构建SERK多突变体的过程中，发现serk1 serk2 bak1三突变体表现出根缩短而根毛极度增多的表型。GUS染色及显微观察发现bak1单突变体中GL2（非根毛细胞的标记基因）的表达模式发生了严重紊乱，与已知的参与根表皮细胞命运决定的另一个受体激酶SCM突变后的表型类似。酵母双杂交实验发现SERKs与SCM具有物理上的相互作用。本项目将在已有的工作基础上，研究SERKs与SCM是否在植物体内形成受体-共受体复合物，共同调控拟南芥根表皮细胞的分化；并筛选与SERKs和SCM互作的蛋白，寻找在受体复合物下游发挥功能参与根表皮细胞命运决定的新因子，从而揭示SCM-SERKs介导的拟南芥根表皮细胞分化的早期信号转导过程。

体细胞胚胎发生类受体激酶SERKs是近年来植物受体激酶研究领域的一组热点蛋白，它们作为共受体参与植物的生长发育和免疫反应等诸多过程。我们在通过反向遗传学构建serk多突变体的过程中，发现serk1-8 serk2-1 bak1-4三突变体表现出根缩短而根毛极度增多的表型，GUS染色及显微观察发现serk突变体中GL2（非根毛细胞的标记基因）的表达模式发生了严重紊乱，即serk突变体根表皮细胞分化命运发生了紊乱，通过遗传回补实验证明其根表皮细胞命运发生紊乱是由于SERKs缺失造成的。结合遗传学、生理生化和转录组学等技术手段证明SERKs作为一组共受体蛋白激酶，既可以通过BR信号与BRI1一起调控拟南芥根表皮细胞命运，又可以与受体激酶SCM互作一起决定拟南芥根表皮细胞命运，即以依赖于和独立于BR信号传导两种方式发挥功能。