Biodiv Sci ›› 2021, Vol. 29 ›› Issue (9): 1236-1244.DOI: 10.17520/biods.2021034

• Original Papers: Microbial Diversity • Previous Articles     Next Articles

Diversity of endophytic bacteria in five types of tissues of Hippophae tibetana

Aimei Zhang(), Yiran Yin, Weibao Kong, Xuetai Zhu, Yingli Yang   

  1. College of Life Sciences, Northwest Normal University, Lanzhou 730070
  • Received:2021-01-25 Accepted:2021-04-22 Online:2021-09-20 Published:2021-05-28
  • Contact: Aimei Zhang

Abstract:

Aims: Hippophae tibetana is a special kind of actinorhizal plants distributed in severe cold and high altitude areas. Frankia spp. can infect its roots and form nodules, which enhances its ecological adaptability due to symbiotic nitrogen fixation and other effects. Besides Frankia spp., there are other endophytic bacteria in the root nodules of H. tibetana. Frankia spp. can distribute not only nodules but also other tissues. By analyzing the community structure and diversity of endophytic bacteria in different tissues, the clonization and possible migration of Frankia in different tissues were discussed.
Methods: High-throughput sequencing of the V5‒V7 region of 16S rRNA gene was used to study the diversity of Frankia spp. and other endophytic bacteria in root nodules, stems, branches, leaves, and seeds of H. tibetana,.
Results: The results showed that the richness and diversity indices of the community in the root nodules of H. tibetana were the highest, while the richness of endophytic bacterial community in seeds were the lowest, and diversity indices in the stems were the lowest. The diversity of endophytic bacterial communities in five types of tissues of H. tibetana was different. Proteobacteria were the dominant phylum of the endophytic bacterial communities of five tissue types, Frankia was the dominant genus in root nodules, while Friedmanniella was the dominant genus in stems, and Stenotrophomonas was the dominant genus in branches, leaves, and seeds. The results also showed that Frankia could not only colonize in root nodules of H. tibetana, but also distributed in other tissues. There were different “species” of Frankia in the same tissue type of H. tibetana, and the same “species” of Frankia were also distributed in different tissues. In addition, functional endophytic bacteria existed in five tissue types of H. tibetana, which can fix nitrogen, promote the growth inhibit pathogens of host plants. Endophytic bacteria with nitrogen fixation function were mainly distributed in nodules, while those with growth-promoting and bacteriostatic functions were mainly distributed in branches and leaves of H. tibetana.
Conclusion: There were rich diversity of endophytic bacteria in five tissue types of H. tibetana, but the community structure and dominant population of each tissue were different, and different tissues could also colonize endophytic bacteria with multiple functions.

Key words: Hippophae tibetana, tissues, endophytic bacteria, diversity, Frankia spp., functional strain