[Growth-promoting effect and triptolide production regulation of endophytic bacteria from Tripterygium wilfordii].

A total of twenty-three endophytic bacteria were isolated from Tripterygium wilfordii, among which three strains were selected for further studying based on their capabilities of growth-promotion and wheat germination. All three isolated strains could produce phytohormone and siderophore, and LG3 and LJ10 strains were capable of dissolving phosphorus. Additionally, LG3 and LY4 strains were both proved to have nitrogen-fixing function and 1-aminocyclopropane-1carboxy-late deaminase activity. Bacterial 16S rDNA sequence identification and homology analysis suggested that LG3 and LY4 strains belonged to the Enterobacter and LJ10 belonged to the Pantoea. The results of reinoculation experiment demonstrated that three endophytic bacteria could not only promote the growth of Tripterygium wilfordii, but also improve the triptolide contents of different organs significantly.