Abstract: The SnRK2 family genes, which are key regulators of plant resistance to abiotic stresses in the ABA pathway, encode a class of serine/threonine protein kinases in plants. Based on the conservative cDNA sequences of SnRK2 members, a full-length cDNA sequence of SnRK2, named as BjSnRK2C, was cloned from Brassica juncea by RT-PCR and SON-PCR methods. The sequencing results showed that the length of full-length cDNA (GenBank accession No. MF983711)was 1 380 bp containing a 3'-UTR of 137 bp, a 5'-UTR of 214 bp, and a complete open reading frame of 1 029 bp with 342 amino acids. The putative molecular weight and theory isoelectric point of the BjSnRK2C protein were 38.2 ku and 5.61, respectively. The BjSnRK2C was a hydrophilic protein with 30 phosphorylation sites, contained two significant transmembrane domains, contained no signal peptide, and might played a physiological role in the cytoplasm. The secondary structure of the BjSnRK2C protein contained 130 α-helixes, 126 random coils, 59 extended strands, and 27 β-turns. The BjSnRK2C protein contained a serine/threonine enzyme activity domain and an ATP binding site, and was at the same evolutionary branch with AtSnRK2.8 from Arabidopsis. The three-dimensional structure of the BjSnRK2C protein kinase was very similar to that of AtSnRK2.8 protein kinase from Arabidopsis, suggesting that they had similar functions. The C terminal of the BjSnRK2C protein kinase contained only the domain Ⅰ, and lacked the domain Ⅱ, suggesting that the BjSnRK2C gene was probably independent of ABA regulatory pathway in abiotic stress process, which will lay a theoretical foundation for further studying the BjSnRK2C gene function.

Key words: Brassica juncea, BjSnRK2C gene, Cloning, Bioinformatics

CLC Number: 

• S649