拟南芥CARK5激酶响应脱落酸信号的研究

Response of CARK5 kinase to ABA signaling in Arabidopsis

摘要:

为了研究拟南芥脱落酸（Abscisic acid，ABA）受体的翻译后修饰，本研究以能够磷酸化ABA受体的激酶CARK5作为研究对象，通过构建了转基因株系来检测CARK5在ABA信号途径中的功能.结果显示： CARK5能够促进ABA介导的抑制种子萌发、幼苗的形态建成以及主根的生长，但是过表达激酶失活型CARK5m（CARK5N250A）则跟突变体cark5表型类似.拟南芥中过表达CARK5增强植株抗旱性；ABA处理后，ABA响应标记基因RAB18表达量增加.这些结果说明，CARK5通过可以磷酸化ABA受体，正调控ABA信号通路.

Abstract:

In order to explore the post-translational modification of Arabidopsis abscisic acid (ABA) receptor, this study constructed overexpressing CARK5 and kinase-dead CARK5m (CARK5N250A) in the wild type and T-DNA mutant cark5 plants by genetic and physiological assays, to analyze the functions of CARK5 in ABA signaling. The results showed that CARK5 can promote ABA-mediated inhibition of seed germination, seedling cotyledon and primary root elongation, but the overexpression kinase-inactive CARK5m (CARK5N250A) has a similar phenotype to the mutant cark5. In addition, overexpressing CARK5 enhanced plant drought resistance and ABA-marked gene RAB18 expression. Taken together, these data suggest that CARK5 positively regulates the ABA signaling pathway by phosphorylation of ABA receptors.