苜蓿根瘤菌转SmnifA基因研究初报

Study of Transfer of Sm-nifA Gene into Rhizobium Meliloti

外源固氮调节基因nifA的导入对根瘤菌的结瘤固氮效率有较明显的促进作用。首先构建带有SmnifA基因的重组质粒,再利用三亲本杂交技术将重组质粒转移至苜蓿根瘤菌XM-1中,得到组成型表达SmnifA基因的菌株,侵染苜蓿后,植株鲜重、干重、含氮量、结瘤数、固氮酶活等指标均优于原始出发菌。

Transferring of reulate gene nifA of N-fixation gene can promote the efficiency of nodulating and N-fixing of the nodula.The recombinant plasmid which has Sm nifA gene was constrcted at first. Then the recombinant plasmid was transferred into the Rhizobium meliloti XM-1 by triparental hybridize.The strain which can express Sm nifA combinantly was used to inoculate the medicago.The result showed that the guidelines of recombinant such as weight,N,nodula,activity of enzyme were higher than XM-1.