Characterization of three Arabidopsis AP2/EREBP family transcription factors involved in ABA sensitivity, freeze and salt tolerance

作     者：MEI WenQian LEI Juan Xu Yu WEI Gang ZHU YuXian 

作者机构：National Laboratory of Protein Engineering and Plant Genetic Engineering College of Life Sciences Peking University Beijing 100871 China 

出 版 物：《Chinese Science Bulletin》 (CHINESE SCIENCE BULLETIN)

年 卷 期：2007年第52卷第13期

页      面：1746-1753页

核心收录：

学科分类：0710[理学-生物学] 071001[理学-植物学] 07[理学] 

基　　金：the National Natural Science Foundation of China (Grant No.30221120261) 

主　　题：阿布属 灵敏度 土壤冻结 盐碱地 

摘      要：AP2/EREBP transcription factors (TFs) play very important roles in plant development, hormonal regulation and stress response. Upon genome-wide cDNA cloning, phylogenetic and expression pattern analyses of this plant specific TF family, we found that three of the members including At1g71450, At1g50680 and At5g13910, were likely involved in responses to ABA, cold and salt. Complementary DNAs containing putative full-length ORFs of these three TFs were obtained and fused individually to the GAL4 DNA-binding domains. All the 3 genes functioned effectively as trans-activators using yeast one-hybrid assays. RT-PCR experiments showed that the At1g71450 gene was induced by ABA and low temperature; the At1g50680 gene was responsive to quite a few stress conditions, but especially to freezing temperature; and the At5g13910 gene was induced by high salt treatment, drought and ethyl-ene. By searching the ABRC T-DNA insertion mutant stocks, we obtained knockout lines for these TFs. Homozygous ko1 (At1g71450) plants showed a hypersensitive response to ABA during seed germina-tion and also in stomata movement. Homozygous ko2 (At1g50680) plants showed a significant reduc-tion in plant freezing tolerance compared to the wild type after chilling treatment. Homozygous ko3 (At5g13910) were less tolerant to high salinity than wild type plants. Our data suggest that At1g71450 is a negative regulator in ABA signaling, while At1g50680 and At5g13910 are positive regulators in cold and salt stress responses, respectively.