Transformation Of Genetic Soybean With GmDREB1Gene And Salt Tolerance Of Transgenic Soybean Plants

When plants are under adversity of excessive salts, the plants endogenous pathwaysare activated to adjust the adaptability to salt so as to minimize the salt stress effect.Related studies indicate the pathway that response to salt stress is attributed to theinteraction of various genes. Because transcription factors confer salt resistance on plantsby triggering expression of downstream genes, relative transcription factors have long beenthe focus on salinization study. So far6types of DREB transcription factors have beenconfirmed in soybean, and studies have been proved the tolerance over drought, coldnessand salt for soybeans can be increased by overexpression of DREB genes.In this study, gene of GmDREB1driven by promoter rd29A was transformed intosoybean mediated by A.tumefaciens,9positive transgenic plants were achieved and thephysiological experiments were conducted on progeny of transgenic soybeans (T2). Theexperimental materials were treated with different salt concentration ranging from0mM to240mM. The results indicated that the transgenic plants possessed better salt tolerance incomparison to wild type soybean. When materials were treated for10days under saltconcentration of240mM, the leaves of wild type soybean became wilted and began dying.However the transgenic plants grew normally. Besides transgenic soybean performedbetter than control group referring to photosynthetic rate, proline, soluble sugar content andmembrane permeability. With treatment of salt-free, no distinction can be detected both intransgenic and non-transgenic groups, however, although photosynthetic rate of transgenicsoybean declined as salt concentration increased, it was still3times higher compare withwild type soybean. Meanwhile, membrane permeability also increased gradually which ishigher than that of control group. Under different salt concentration, abundant solublesugar and proline were accumulated, transgenic soybean thereby can be more resistant tosalt stress than wild type soybean.The experimental results suggested the injury of transgenic plants caused by salt stresswas smaller than the control group plants. It’s reasonable to believe that overexpression ofGmDREB1regulates certain downstream gene which make transgenic soybean moreresistant to salt stress. The new material produced in this study may provide new prospectfor further stress resistant research.