Expression Analysis Of Fifteen Candidate Stress-Tolerant Genes And Functional Identification Of AmDREB1 From Ammopiptanthus Mongloicus

Ammopiptanthus mongloicus is a typical plant with strong resistance to abiotic stresses in the northwest of China. It is of great significance to study on its genetic mechanism of resistance to stresses at the molecular level. In this study, ased on the digital expression profiling of A. mongloicus performed previously in cur laboratory, fifteen cold-and drought-induced genes were selected as candidate stress-toierant genes from this species. The transcriptional changes of these genes in natural conditions in the wild were analyzed by the semi quantitative RT-PCR method. In addition, the preliminary functional analyses of AmDREB1-1 and AmDREB1-2 genes were performed through their transgenic Arabidopsis. The main results are as follows:(1) Among the fifteen candidate genes, twelve genes showed significant up-regulation in their transcription levels in autumn and winter seasons in the wild conditions, including six transcription factor genes such as AmDREBl and two unknow-genes. The results indicate that the twelve genes were mainly involved in the response of A. mongloicus to its cold environment.(2) Through stress resistance identification of its over-expressing Arabidopsis lines, it was shown that AmDREB1-1 mainly plays a role in the resistance to water deficit at the seed germination stage.(3) The complete coding region cDNA of AmDREB1-2 contains 474 base pairs, and its predicted polypeptide has a single amino acid difference at the 137th (P or S) compared with AmDREBl-1. The coding region cDNA fragment of AmDREB1-2 was successfully ligased to plant over-expression vector and introduced into Arabidopsis. Through preliminary functional analysis of the T2 transgenic lines, it was shown that AmDREB1-2 also plays a role in the resistance to water deficit at the seed germination stage.