利用标记基因lacZ研究根瘤菌对烟草发根的侵染

Study on Rhizobia Infections to Tobacco Hairy Roots by Using Reporter Gene lacZ

摘要:

用发根农杆菌菌株LBA1314采用叶盘法对烟草进行转化,诱导烟草发根。将标记基因nifHDK-lacZ、nifH-lacZ、hemA-lacZ通过三亲交配法导入根瘤菌,然后接种烟草发根。β-半乳糖苷酶组织化学染色和徒手切片观察表明,野生型根瘤菌可以感染烟草发根,回接试验证明侵染烟草发根的细菌是根瘤菌

Abstract:

Tobacco hairy roots were induced by A.rhizogenes strain LBA1314 using leaf disc transformation.The plasmids haboring the reporter gene lacZ fused to the promoters of hemA,nifHDK,and nifH respectively,were transformed into rhizobia by triparental mating and the conjugated rhizobia were inoculated into tobacco hairy roots.The results indicated that the histochemical staining of β-galactosidase and a cross-section of tobacco hairy roots showed that the rhizobia could infect or enter into the non-legume tobacco hairy roots.The bacteria isolated and purified from the colonized roots,which were stained again for β-galactosidase activity,were reinoculated into legume pea for nodulation.It was showed that the bacterias in the formed nodules with blue color after β-galactosidase staining were the pea rhizobia with lacZ reporter gene.