Characteristic And Functional Identification Of Stress-resisitent Related Transcription Factor Genes, GmDREB5 And GmERF1, From Soybean (Glycine Max)

AP2/EREBP transcription factors exist in all kinds of plants, such as Arabidopsis, maize, tomato, tobacco and rice et al., and regulate the expression of many genes in plant. In AP2/EREBP family, DREB and ERF transcription factors play important roles in response to biotic and abiotic stresses. In our lab, new DREB and ERF genes, GmDREB5 and GmERF1, were successfully cloned from Glycine max. The results of electrophoretic mobility shift assay (EMSA) indicated that GmDREB5 protein specifically bound to DRE (Dehydration-Responsive Element) and GmERF1 protein specifically bound to ERE (Ethylene-Responsive element or GCC-box element) and DRE in vitro; The results of transcriptional activate assay indicated that GmDREB5 protein specifically bound to DRE and activated the expression of report gene LacZ in yeast cells, which showed GmDREB5 protein had transactivation activity. The results of transient expression assay in tobacco indicated that GmERF1 protein specifically bound to DRE and activated the expression of report gene GUS, which illuminated GmERF1 protein had transactivation activity in plant cell; The results of Northern blot indicated that expression of GmDREB5 gene was induced by dehydration and high salt stresses obviously, and was not induced by cold stresses and ABA treatment, and expression of GmERF1 was induced by dehydration, high salt stresses and ABA treatment, but was not induced by cold stress; GmDREB5 and GmERF1 were transformed into tobacco using the agrobacterium-mediated transformation. We obtained 37 lines of CaMV35S∷GmDREB5 transgenic plants and 35 lines of CaMV35S∷GmERF1 transgenic plants and 29 lines of rd29A∷GmERF1 transgenic plants. The function analysis of transgenic tobacco showed that overexpression of GmDREB5 gene improved tolerance to dehydration and high salt stresses and overexpression of GmERF1 gene improved resistent against the bacterial pathogen Pseudomonas solanacearum. In this thesis, characteristic and function of GmDREB5 and GmERF1 genes were studied at detail. The results showed that GmDREB5 and GmERF1 genes have characteristic of DREB and ERF transcription factors and expression of these two genes in transgenic plant could improve tolerant to abiotic stresses and resistant against the bacterial pathogen, which is advantage for our to study the molecular mechanism of these two transcription factors regulating the signal network of response to environmental stresses in plant, and provide a new genes to improve crop tolerance to adverse environmental conditions.