苦荞转录因子FtDREB6基因克隆及其抗旱功能鉴定

Cloning of A Transcription Factor Gene FtDREB6 in Tartary Buckwheat(Fagopyrum tataricum)and Identification of Its Function in Drought Resistance

AP2/ERF转录因子家族在植物逆境胁迫中发挥重要作用,本研究以品苦1号为材料,从中克隆得到FtDREB6基因,该基因CDS全长615 bp,编码204个氨基酸,编码蛋白分子量为22.7 kDa,等电点为4.96。在Tair网站上将其与拟南芥进行同源比对,发现其与拟南芥AtERF043同源性较高。转录激活活性分析表明,FtDREB6全长没有自激活活性。利用农杆菌介导法将FtDREB6基因转入拟南芥,过表达FtDREB6基因显著提高转基因拟南芥的抗旱性。将FtDREB6基因转入发根农杆菌A4,侵染苦荞外植体诱导毛状根,在甘露醇处理下,过表达毛状根的SOD和CAT活性显著高于对照组,且MDA含量显著低于对照组。以上结果表明,FtDREB6参与苦荞干旱胁迫反应,为进一步研究苦荞抗旱分子机制提供了参考。

AP2/ERF transcription factor family members have been identified to play important roles in abiotic stress responses.In this study,the full-length coding sequence of the FtDREB6 gene was cloned with a length of 615 bp,which encodes for 204 amino acids residues,with a molecular weight of 22.7 kDa and an isoelectric point of 4.96 from tartary buckwheat(Fagopyrum tataricum(L.)Gaertn.)cultivar Pinku 1.The sequence of FtDREB6 represented higher homology with Arabidopsis thaliana(L.)Heynh.AtERF043 by the sequence alignment on TAIR website.FtDREB6 gene was showed without the transcription activity by transactivation analysis.Moreover,by transforming the coding sequence of FtDREB6 into A.thaliana by Agrobacterium-mediated transformation approach,transgenic FtDREB6-overexpressing plants showed significant increase on the drought resistance.The expression vector containing FtDREB6 gene was transformed into Agrobacterium rhizogenes(Riker et al.)Conn A4,which was subjected to infect explant for inducing the hairy roots.Under D-Mannitol treatment,the superoxide dismutase activity and catalase activity in overexpressing hairy roots were significantly higher than that of the control,and the content of malondialdehyde was significantly lower than the control.These results indicated that FtDREB6 was involved in responses to drought stress,which provided a reference for future deciphering the molecular mechanism for drought tolerance in tartary buckwheat.