Biotechnology Bulletin ›› 2022, Vol. 38 ›› Issue (9): 237-247.doi: 10.13560/j.cnki.biotech.bull.1985.2021-1577

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Colonization on the Peanuts of Two Plant-growth Promoting Rhizobacteria Strains and Effects on the Bacterial Community Structure of Rhizosphere

LI Ying(), LONG Chang-mei, JIANG Biao, HAN Li-zhen()   

  1. College of Life Science/Institute of Agro-bioengineering,Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountain Region(Ministry of Education),Collaborative Innovation Center for Mountain Ecology & Agro-Bioengineering(CICMEAB),Guizhou Univeristy,Guiyang 550025
  • Received:2021-12-21 Online:2022-09-26 Published:2022-10-11
  • Contact: HAN Li-zhen E-mail:1363393909@qq.com;lzhan1@gzu.edu.cn

Abstract:

This work aims to investigate the growth-promoting mechanism of two plant growth-promoting rhizobacteria(PGPR)strains,Tsukamurella tyrosinosolvens P9 and Burkholderia pyrrocinia P10 on peanut. The two strains were labeled with GFP and rifampicin,respectively,and colonization dynamics of 2 strains in peanut tissues were studied,combined with scanning electron microscopy. Bacterial diversity of rhizosphere soil inoculated with 2 strains was analyzed by 16S rRNA whole-length sequencing. It showed that rifampicin-labeled strains P9 and P10 had good genetic stability,and their growth and growth-promoting characteristics were consistent with original strains,respectively. Two GFP-labeled strains colonized in the root tip and meristematic region of peanut. Rifampicin-labeled strains were stabilized in the roots and stems of peanut plants,and the colonization number remained 104 CFU/g after 30 d of inoculation. In addition,the bacterial communities in inoculation groups of P9 and P10 and mixed strains were more similar than those in the un-inoculated control group. In three inoculation groups,the relative abundance of Flavihumibacter and unidentified_Rhizobiaceae increased significantly,and that of Bacillus and Streptomyces increased in different degrees compared with CK,while the abundance of Lysobacter,Achromobacter and Pseudoxanthomonas decreased. The two PGPR strains could not only directly colonize in peanut tissues,but also indirectly affect soil bacterial community structure to promote the growth of peanut. The inoculation of mixed strains had better growth promotion effect on peanut. The results clearly elucidate the growth-promoting mechanism of the two PGPR strains,and provide scientific basis for the further application of the strains.

Key words: Tsukamurella tyrosinosolvens, Burkholderia pyrrocinia, peanut, colonization, bacterial community structure