Functional Analysis Of TaGAPCp1/2 Gene And Their Promoters Under Abiotic Stress In Chinese Spring Wheat

GAPCp are ubiquitous proteins that play pivotal roles in plant metabolism and involved to stress.However,the precise role of GAPCp in wheat against abiotic stresses is not completely understood.Here we isolated,identified and characterized the TaGAPCp1/2 gene and their promoter from wheat Chinese Spring for further investigation.Their expression profiles were analyzed by RT-q PCR.Subcellular localization assay was performed,and a fluorometric assay was conducted for quantitative determination of GUS activity.The results are as follows:1.TaGAPCp1/2 gene were cloned and their full-length were 1166 bp and 1246 bp respectively.TaGAPCp1 gene exhibits higher sequence identity to TaGAPCp2.2.Subcellular localization results demonstrated that TaGAPCp1/2 are plastoprotein.3.Expression profiles of TaGAPCp1/2 gene revealed that they showed remarkable tissue specificity and expresses constantly throughout the plant developmental stages.Relative expression of TaGAPCp1/2 gene showed a different response to various stresses.They were induced remarkably by water-deficit and salinity stress,and slightly responded to ABA hormone treatment in leaf.Exposed to osmotic stress,ABA and H₂O₂,the expression of TaGAPCp1/2 gene were changed significantly.4.Wheat seedlings were pretreated with tungstate for 6 h followed by PEG treatment.The results clearly showed that TaGAPCp1/2 was down-regulated at 6 h after the treatment with PEG and ABA.Pretreatment with inhibitors or scavenger of H₂O₂didn’t inhibite the up-regulation of TaGAPCp1/2 in the PEG6000-treated wheat seedlings.5.The 1950 bp or 1921 bp of corresponding upstream regulatory region of TaGAPCp1/2 gene was obtained by PCR.According to the analysis of Plant CARE Promoter Prediction databases,all the putative cis-acting elements can be classified into three groups:defense and stress-responsive elements（DSREs）,hormone-responsive elements（HREs）and light-responsive elements（LREs）.GUS activity analysis showed that TaGAPCp1/2 promoter could drive the expression of GUS gene and was significantly induced by water-deficit.