Abstract:

Abstract: In this study, homology-based cloning was used to clone hemoglobin gene of lba and nodulation gene of nodD. The two genes were ordered joined into downstream of lac promoter and connected by the DNA recombinant technique to constructed expression vector pTR-P_lac-nodD-lba marked by luxAB gene. The vector was transformed into Sinorhizobium fredii with the method of triparental hybridization to construct genetic engineering strain. Western blot indicated the genes we used can express normally. Strains were inoculated soybean seedlings in order to get nitrogenase activity. The result showed engineering strains can improve the nitrogenase activity and the engineering strain with tandem genes can enhance nitrogenase activity 4% and 15.1%, respectively, by contrast with engineering strain with lba or nodD gene.

Key words: Nodulation gene nodD, Glycine max leghemoglobin gene lba, Sinorhizobium fredii, Triparental hybridization