Response of CARK5 kinase to ABA signaling in Arabidopsis

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.