Overexpression Of A ZmSnRK2.12 Gene And Conferring To Drought Tolerance In Arabidopsis Thaliana

Maize is one of the most major economic crops in the world,drought stress is a major constraint factor for maize production.The sucrose non-fermenting-1 related protein kinase 2 (SnRK2) is a a class of serine/threonine family of protein kinases associated with abiotic stress signal transduction in plants and abscisic acid (ABA)-dependent plant development.In our study, We found 7 and 14 members in the SnRK1/2 gene family respectively. Phylogeny, conserved motifs and promoters of maize SnRK1/2 have been analyzed. All of the 21 SnRK genes were identified in zea mays and clustered into groupsⅠ,Ⅱ,andⅢ. Quantitative real-time PCR was used to analyze the expression patterns in B73. Most of the SnRK2 members were induced by one or more abiotic stresses. Under different stress, all SnRK2 genes were up-regulated and peaked at different times. Based on the digital gene expression profiles in H21and Ye478 both in control and drought stress, statistical analysis of genes with expression in SnRK1/2 family indicate that:the numbers of SnRK2 genes with up-regulated expression in H21 and Ye478 are 8 and 9 respectively, in which 6 members in common, like SnRK2.12; the numbers with down-regulated expression are 5 and 4 respectively, and 2 was down-regulated observably in common.To investigate the role of ZmSnRK2.12 under stresses, an overexpression vector pDMC83-ZmSnRK2.12 was constructed, The full-length cDNA of ZmSnRK2.12 was 1,684 bp with an open reading frame (ORF) of 1,096 nucleotides, which encoded 364 amino acids with a predicted molecular mass of 41.8 kDa.The overexpression vector was introduced into Agrobacterium tumefaciens strain GV3101 via the freeze-thaw method and transformed into Arabidopsis thaliana using floral dipping. PCR analysis indicated the SnRK2.12 gene was integrated into the genome of Arabidopsis, and western blot analysis demonstrated the ZmSnRK2.12 protein was expressed in C83 transgenic Arabidopsis.Collectively, all the results indicated that overexpression of ZmSnRK2.12 gene in transgenic arabidopsis enhanced tolerance to drought stresses.