Cloning And Functional Analysis Of Transcription Factor RdreB1 Gene In Rice(Oryza Sativa L.)

Plant grows in an inconstant environment that frequently imposes constrains on growth and development. They respond and adapt to stress to survive environmental stress conditions. Drought, high salinity and low temperature are commonly adverse environmental conditions that affect the growth of plants and the productivity of crops. All of these environmental stresses are called water stress. A variety of genes have been reported to respond water stress in various species, and the functions for many of the proteins they encode have been predicted from sequence homology with known proteins. Genes induced during water-stress conditions are thought to function not only in protecting cells from water deficit by the production of important metabolic proteins but also in the regulation of genes for signal transduction in the water-stress response. There are two pathways involved in the water-stress response, ABA-dependent pathway and ABA-independent pathway. The transcription factor RdreB1 of Oryza Sativa discussed this article is involved in the ABA-independent pathway, it specifically binds to a 9-bp conserved sequence, TACCGACAT, termed the dehydration-responsive element(DRE) in the promoter region of rd29A gene. The RdreBl gene plays an important role in the induction of expression of stress-induced genes in water-stressed environment.Using cis-element rd29A3cis as a bait, we isolated the transcription factor RdeBl that specifically binds to the bait sequence in a cDNA library of Oryza Saliva by yeast one-hybrid system. Analysis of sequence homology with known genes indicated that this transcription factor with 219 amino acids, which has a conserved DNA binding domain present in a large family of EREBP/AP2 and contains a basic region in its N-terminal region that might function as a nuclear localization signal and an acidic C-terminal region that might act as an activation domain for transcription, belonged to EREBP/AP2 transcription factors.The results of RT-PCR analysis for Oryza Sativa IR36 suffered by various treatments indicated that the mRNA of gene RdreBl was induced effectively by drought and low temperature.Through a simplified method for Agrobacterium-mediated transformation of Arabidopsis thaliana Columibia-floral dip, we successfully got transgenic plants which can grow well in drought and low-temperature stress.