生物多样性 ›› 2021, Vol. 29 ›› Issue (9): 1236-1244.DOI: 10.17520/biods.2021034

• 研究报告:微生物多样性 • 上一篇    下一篇

西藏沙棘5种不同组织内生细菌多样性

张爱梅(), 殷一然, 孔维宝, 朱学泰, 杨颖丽   

  1. 西北师范大学生命科学学院, 兰州 730070
  • 收稿日期:2021-01-25 接受日期:2021-04-22 出版日期:2021-09-20 发布日期:2021-05-28
  • 通讯作者: 张爱梅
  • 作者简介:* E-mail: zhangaimei@nwnu.edu.cn
  • 基金资助:
    国家自然科学基金(31360005);甘肃省重点研发计划(20YF3FA043);兰州市人才创新创业项目(2020-RC-84)

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

摘要:

西藏沙棘(Hippophae tibetana)是分布于高寒高海拔地区的一类特殊的放线菌结瘤植物, 弗兰克氏菌能够侵染其根部形成根瘤, 因共生固氮等作用而增强其生态适应性。在西藏沙棘的根瘤中, 除了弗兰克氏菌之外还有其他内生菌, 而弗兰克氏菌又不仅仅在根瘤中有分布。为了探究弗兰克氏菌在西藏沙棘不同组织中的定殖及可能的迁移规律, 分析不同组织中内生细菌的群落结构及多样性, 本研究以生长在甘肃省天祝藏族自治县抓喜秀龙金强河河滩地的西藏沙棘为材料, 应用16S rRNA扩增子高通量测序技术, 对西藏沙棘根瘤、茎、枝、叶和种子等不同组织的内生细菌多样性进行了分析。研究结果表明, 西藏沙棘根瘤内生细菌群落丰富度及多样性最高, 种子内生细菌群落丰富度最低, 茎内生细菌群落多样性最低。西藏沙棘5种不同组织中的弗兰克氏菌和其他内生细菌多样性都具有一定差异, 变形菌门均为优势门, 弗兰克氏菌属(Frankia)为根瘤内生细菌群落的优势属, 弗莱德门菌属(Friedmanniella)为茎内生细菌群落的优势属, 寡养单胞菌属(Stenotrophomonas)为枝、叶和种子内生细菌群落的优势属。研究结果还表明, 弗兰克氏菌属不仅仅存在于西藏沙棘的根瘤, 还能够分布于其他组织, 且在同一种组织中存在弗兰克氏菌属的不同“种”; 而在西藏沙棘不同组织中, 也分布有弗兰克氏菌属的相同“种”。此外, 对西藏沙棘5种不同组织内生细菌中的功能菌株的分析表明, 不同组织中均存在着具有固氮、促生和抑菌功能的内生细菌, 但具有固氮作用的内生细菌主要分布于根瘤, 具有促生作用以及抑菌功能的内生细菌主要分布于枝和叶。综上, 西藏沙棘5种不同组织内生细菌具有丰富的多样性, 但各组织内生细菌的群落结构和优势种群有所不同, 且不同组织也能够定殖具有多种功能的内生细菌。

关键词: 西藏沙棘, 组织, 内生细菌, 多样性, 弗兰克氏菌, 功能菌株

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