Function Analysis Of AtSnRK2.4 And AtMYB21 In Arabidopsis Thaliana

Sucrose non-fermenting-1(SNF1)-related protein kinase 2(SnRK2)are serine/threonine-specific protein kinase which exists only in plant.SnRK2 plays major roles in signaling transduction and in response to environmental stress such as salt and drought,as well as some essential physiology processes.And some researches have suggested that SnRK was a promoter in the Phosphorylation process of proteins.R2R3-MYB transcription factors play an important role in multiple biological processes,such as development,metabolism and responses to stresses.Many efforts have been devoted to the characterization and functional analysis of plant R2R3-MYB transcription factors.AtSnRK2.4,a SnRK2 protein kinase family member in Arabidopsis thaliana.In the before study,We used AtSnRK2.4 as bait,using a yeast two-hybrid system to screen for the interacting protein.Here,AtMYB21 containing 226 amino acids,one of R2R3-MYB transcription factors in Arabidopsis,identifying interaction between two proteins,was finally identified as a interacting partner of AtSnRK2.4 through a yeast two-hybrid assay.It laid a foundation for exploring the resilience mechanism.In this study,we cloned AtSnRK2.4 and AtMYB21 genes.We have tested that AtSnRK2.4 as a promoter in the Phosphorylation process of AtMYB21 proteins using Phos-tag SDS-PAGE and Western blot methods in vivo.Using GFP fluorescence labeling technology,the fluorescence signals of AtSnRK2.4-GFP and AtMYB21-GFP were similar to the GFP signals and were presented in cytosol into onion epidermal cells.And real-time quantitative PCR was conducted to analysis of the expression of A tSnRK2.4 and AtMYB21 gene at mRNA level.Expression of AtSnRK2.4 and AtMYB21 gene were induced by salt,ABA and Mannitol,and changed with the time extending,which suggested that there were some response relationship between the expression of AtSnRK2.4 and AtMYB21 gene and environment(Salt,ABA and drought)stress.In the mutants assays,we analyzed the phenotype,such as the root length,fresh weight and seed germination of plants.And these dates indicated that AtSnRK2.4 and AtMYB21 regulated the tolerance to mutiple abiotic and oxidative stresses.It laid a foundation for further studying molecular mechanism of AtSnRK2.4 and AtMYB21 gene in response to adverse environment such as salt and drought.