Abstract: DREB(dehydration responsive element binding protein)is a type of transcription factor commonly existing in higher plants, and involves in abiotic stress response and the process of growth and development. In this study, using Zoysia japonica var. pallida cv Jiaodong as material, the coding sequence of gene DREB2.2 was cloned, then the bioinformatics were analyzed, and the expression profile of the gene in the stress environment was detected by semi-quantitative PCR technique. Sequencing analysis indicated that DREB2.2 had 2 transcripts of long and short. The long transcript, DREB2.2-L, was 1 067 bp in length, with a premature ORF because of a 50 bp insertion sequence, and putatively encoding 65 amino acids. The short one, DREB2.2-S, was 1 017 bp in length, encoding 338 amino acids;the putative protein was 37.3 kD, pI was 4.86, and it belonged to the A-2 group of DREB subfamily, containing an AP2 conservative structure domain and nuclear localization sequence. The results of semi-quantitative PCR showed that both DREB2.2-S and DREB2.2-L were expressed in normal condition, the expressions were up-regulated under low temperature stress with the highest level at 2 h exposure, and were slightly up-regulated during the 2 h and 24 h of drought stress, but showed no response to high salt stress. In both normal and stress conditions, the mRNA amount of DREB2.2-L was slightly higher than that of DREB2.2-S.

Key words: Zoysia japonica var. pallida cv Jiaodong, transcription factor, DREB, abiotic stress.