Functional Analyses Of DREB Transcription Factor Genes From Soybean (Glycine Max), And Isolation And Identification Of Its Interacting Proteins

DREB transcription factors exist in all kinds of plants, and regulate the expression of many stress-related genes and play important roles in response to abiotic stresses in plants.In this study, the functional analysis of transgenic plants showed that overexpression of GmDREB5 improved tolerance to drought stress and the overexpression of GmDREB3 gene in transgenic Arabidopsis enhanced tolerance to cold stress. The drought tolerance analyses of transgenic wheat indicated overexpression of GmDREB1,GmDREB3 and GhDREB genes improved tolerance to drought stress, and transgenic wheat lines showed different drought resistance. The results of PCR identification indicated that transferred DREB genes had been inherited stably to next generation and played important roles in improving drought resistance of transgenic wheat plants, which was very important for improving drought resistance of Chinaese primary wheat varieties and improving other crops using these DREB genes.It was reported that DREB transcription factor regulate expression of several downstream genes, which enhanced plant tolerance to various stresses and the activity of DREB was regulated by other interaction proteins in translational level. Therefore, screening of novel DREB interaction proteins is the foundation to clarify the regulating mechanism of DREB transcription factors. In this research, cDNA library of sybean seedling drought treated for 5 h was constructed for screening using yeast two hybrid system. After strict screening, 580 potential interacting proteins of GmDREB5 were isolated. Then, after re-identified using various methods, some interacting protein were proven containing GmGβ1,GmTPR1,GmE2,GmLC1 and GmPSI, which showed strong interaction with GmDREB5 protein. The expression analysis of these interaction proteins indicated that those expressions were all induced by drought, low temperature, high salt and ABA but expression rhythm were different. The homology analysis indicated that amino acid sequence of those interaction proteins has similarity with known proteins in other plants, suggesting that those proteins were novel proteins in soybean. The pull-down and western blot assay confirmed the interaction between GmDREB5 and GmE2. The isolation of GmDREB5 interacting proteins was important foundation to clarify the regulating mechanism of DREB transcription factors in translational level.