Transformation Of Tobacco With MfDREB1and MfDREB1s Gene From Medicago Falcate

In this study, two Medicago falcate DREB1transcription factor family genes, MfDREBl and MfDREBls, were transformed to tobacco and T1generation of transgenic plants had been obtained, which were further used to explore MfDREBl and MfDREBls cold resistance biology function.Using plant binary expression vector pPZP221as the basic frame, we used both constitutive promoter CaMV35S and stress inducible promoter rd29A to construct two kinds of target genes plant expression vectors, which were transformed to tobacco by Agrobacterium-mediated methods. We also generated transgenic tobacco carrying pPZP221(35S:NOS) or pPZP221(rd29A:NOS) as control plants. Based on the plant selectable marker screening, the obtained To generation plants were detected by PCR method to test whether target genes integrated into the tobacco genome. T1generation was acquired by the To plants self-pollination. Parts of T1plants were cold treated with1℃for25days after gentamicin selection, then we examined the expression levels of downstream gene NtERD10A by semi-quantitative PCR method.Results of this study are as follows:(1)78lines of MfDREBl and MfDREBls transgenic tobaccos had been obtained:23lines of35S:MfDREB1;14lines of rd29A:MfDREB1;22lines of35S:MfDREB1s and19lines of rd29A:MfDREB1s.(2)38lines of control plants had been obtained:16lines of35S:NOS;22lines of rd29A:NOS.(3) Semi-quantitative PCR analysis showed that stress-related gene NtERD10A expression levels in35S:MfDREB1and35S:MfDREB1s transgenic plants were higher than that in control plants under cold stress. During recovery process from cold stress, we observed that freezing injury of control plants was severe than that of transgenic plants. These results suggest that MfDREBl and MfDREB1s may act as a transcription factors to induce stress-related genes expression, thereby improving plants tolerance to cold stress.