拟南芥CARK11参与ABA介导的生理功能研究

CARK11 involves in ABA-mediated physiological functions in Arabidopsis

摘要:

为了探究CARK11在ABA介导的生理进程中的具体作用，本研究以拟南芥哥伦比亚生态型（WT）、CARK11功能缺失突变体cark11和回补激酶丧失CARK11N203A（com-CARK11m）以及过表达转基因株系（OE-CARK11）为研究对象，探究CARK11在种子萌发、幼苗形态构建、主根生长与干旱响应中发挥的作用. 结果显示：相比WT，ABA促进了cark11和com-CARK11m的种子萌发、子叶变绿和主根伸长，而OE-CARK11被抑制. qRT-PCR检测RAB18和RD29a的表达量，发现过表达CARK11促进RAB18和RD29a表达；ABA处理后，这种促进作用更强. 干旱实验发现，OE-CARK11耐旱性增加，而cark11和com-CARK11m耐旱性弱于WT. 这些结果表明：CARK11作为ABA信号通路的正调控因子抑制拟南芥的种子萌发、子叶变绿和主根生长；同时在干旱胁迫中具有积极作用；另外CARK11在ABA信号途径中的功能依赖激酶活性.

Abstract:

In this study, the purpose is to explore the specific role of CARK11 in ABA-mediated physiological processes. Arabidopsis Columbia ecotype(WT), T-DNA mutant cark11, complementation of kinase-dead CARK11N203A in the background of cark11, (com-CARK11m), and overexpression transgenic lines(OE-CARK11) were used in this study to determine the roles of CARK11 during seed germination, seedling morphogenesis, primary root growth, and drought tolerance. The results showed that compared with the WT, ABA promoted seed germination, cotyledon greening, and primary root elongation in both cark11 and com-CARK11m, while OE-CARK11 was relatively inhibited. In addition, qRT-PCR data showed that overexpression of CARK11 promoted the expression of RAB18 and RD29a, which were ABA-marked genes, and this facilitation was stronger after ABA treatment. In the drought tolerance assay, the results revealed that OE-CARK11 enhanced drought tolerance, while cark11 and com-CARK11m were weaker than WT. Thus, we conclude that CARK11 acts as a positive regulator in the ABA signaling pathway and inhibits seed germination, cotyledon establishment, primary root growth and drought stress in Arabidopsis. Notably, the function of CARK11 is dependent on kinase activity in the ABA signaling pathway.