Expression And Functional Analysis Of A Novel AaDREB1 Transcription Factor From Adonis Amurensis

Plant growth and productivity is greatly affected by low temperature, drought and high-salt. DREB transcription factor is a dehydration responsive element (DRE) binding protein. It can specifically interact with the dehydration-responsive element/C-repeat (DRE/CRT) cis-acting element contained in the promoter contain many stress-inducible genes, therefore, it controls the expression of many stress-inducible genes in plant and increases strong tolerance to low temperature, drought and high-salt. DREB transcription factor plays an important role in the expression of many stress-inducible genes in plant, so it thus shows a very broad application future in aspect of increasing strong tolerance to stress. In this paper, the organ-specific expression patterns of AaDREB1 (GenBank accession number:AF441123) and the expression of AaDREB1 under different stresses was analyzed by semi-quantitative RT-PCR. One-Hybrid System was constructed to analyze the in vitro interaction of AaDREB1 and the DRE element. Also, the plant expression vectors of AaDREB1 gene were constructed and transferred to Arabidopsis and rice separately by Agrobacterium-mediated methods, then analyzed the phenotype of transgenic Arabidopsis and rice under different stresses. The main results are as follows:(1) Semi-quantitative RT-PCR results indicated that AaDREBl was constitutively expressed in almost all of the tissues and organs examined, including the leaves, roots, stems and flowers, AaDREB1 gene can also be induced by high-salt, drought, cold stress, and ABA application.(2) A yeast one-hybrid assay demonstrated that AaDREBl gene encodes a transcription activator and specifically binds to DRE/CRT and activated the expression of the reporter gene.(3) Overexpression of AaDREBl gene in Arabidopsis led to enhanced tolerance to high-salt, drought and low-temperature.(4) Under high-salt stress treatment, Survival rates and chlorophyll contents Statistical analysis of transgenic and wild-type rice showed that overexpression of AaDREB1 improved high-salt tolerance of transgenic rice plants.(5) Survival rates and soluble sugar contents statistical analysis of transgenic rice were increased comparing with wild-type rice, which revealed that overexpression of AaDREBl improved drought tolerance of transgenic rice in the condition of drought stress treatment.(6) Compared to wild-type rice, survival rates and protine concentrations statistical analysis of transgenic rice showed that overexpression of AaDREB1 in rice improved freezing stress tolerance after low-temperature stress treatment.