Cloning Of Transcription Factor DREB1 Gene And Expression In Soybean And Alfalfa

Soybean and alfalfa are important economic crops in China. It is an efficiency way that using transgenic technique produces special genetic modification to improve alfalfa and soybean traits. Regulation gene expression related to ion metabolism, organic substance accumulation and transcription factor is a key factor to improve salt-tolerant in alfalfa and soybean. Cultured salt-tolerant alfalfa and soybean will supply an important measure to utilize and improve salt-alkali soil.There are a number of transcription factors, and the DREB series play an important role in the stress tolerance of plants. They could activate the expression of a series of stress-tolerance genes, such as rd29A, cor15a and rd17 etc., and they could also increase the contents of proline and sucrose to improve the stress-tolerant ability. The rd29A promoter gene of Arabidopsis and DREB1 gene of soybean were cloned in this study and the gene sequences were almost the same with those from the GenBank containing the necessary functional parts. And recombinant salt-inductive expression vector with rd29A promoter and DREB1 gene was constructed and then transformed into soybean and alfalfa by Agrobacterium-mediated. Some positive transgenetic plants have been obtained until now. To confirm DREB1 function, the DREB1 was over-expressed in Arabidopsis. The 6 transgenic T1 plants showed higher salt tolerance than wild type in containing NaCl medium. The result indicated that the vector harboring rD29A promoter and DREB1 gene will improve transformed alfalfa and soybean.salt tolerance. In this study, soybean, Jilin 35, was taken as experimental material. About 128 explants were infected using embryonic tip transformation system, and 61 resistant shoots were obtained through antibiotic screening. 39 plants were survived after engrafting resistant shoots on rootstock. The survival rate was 63.9%. PCR assay showed that 7 plants were positive. And transformation efficiency reached up to 17.9%.Alfalfa, GZL-1, was transformed using leaf transformation system. About 242 resistant calluses were obtained after infected 1425 explants. Transformation efficiency reached up to 16.9%. At present, about 20 plants were transplanted into soil. PCR assay indicated that the gene of interest was integrated into all plants genome.This paper provided the experimental evidence for studying the expression and control of the transcription factors in soybean and alfalfa and the basic materials and technology for selection of stress-tolerant soybean and alfalfa.