不同水稻组织内生细菌的群落多样性

Diversity of bacterial endophytic community in different rice tissues

摘要:

[目的]为详细了解水稻不同组织内生细菌群落多样性。[方法]对宁粳43号内生细菌的总DNA提取后，采用高通量测序技术对水稻内生细菌的16S rRNA基因进行了序列测定，分析了水稻不同组织部位内生细菌群落结构特征。[结果]叶部共获得内生细菌OTUs 610个，茎部411个，根部174个。物种分类显示，叶部内生细菌种类隶属于22门40纲103目198科399属，其中优势类群是红球菌属（Rhodococcus）和乳酸杆菌属（Lactobacillus），它们的相对丰度分别为21.00%和9.19%；茎部内生细菌种类隶属于19门31纲85目169科306属，其中优势类群是红球菌属和罗尔斯通菌属（Ralstonia），它们的相对丰度分别为19.25%和13.52%；根部内生细菌种类隶属于9门19纲44目82科140属，其中优势类群是肠杆菌属（Enterobacter）和埃希氏杆菌属（Escherichia），它们的相对丰度分别为81.13%和10.89%。根茎叶中相同的OTU有78个，放线菌门（Actinobacteria）与大多数细菌具有相关性。根系内生细菌中具有调控各种代谢网络功能的物种丰度高于茎部和叶部。[结论]不同水稻组织内生细菌具有丰富的群落多样性，其中叶部的内生细菌物种最丰富，根系参与各种代谢调控的细菌丰度最高，各个组织部位的优势菌属各不相同，变形菌门是最重要的水稻内生细菌。

关键词:多样性;内生细菌群落;不同水稻组织;高通量测序;微生物生态学

Abstract:

[Objective] Our study aims to understand the microbial diversity of endophytic bacterial community of different rice tissues.[Methods] We adopted high-throughput sequencing technology to study the microbial community structure and composition of bacterial endophytes in rice plant. We extracted DNA of the microbial community of bacterial endophytes in the rice var. No. 43 of Ningjing. The bacterial 16S rRNA gene hypervariable region V5-V7 was detected by high-through sequencing technologies.[Results] In total 610 OTUs were obtained from leaf bacterial endophytes, 411 OTUs from rice stem, 174 OTUs from rice root. Based on the results of species classification, leaf endophytic bacteria were represented by 22 phyla that mainly comprised 40 classes, 103 orders, 198 families, and 399 genera. Among them, the predominant genera were Rhodococcus and Lactobacillus, and their relative abundances were 21.00% and 9.19%, respectively. Stem endophytic bacteria were represented by 19 phyla that mainly comprised 31 classes, 85 orders, 169 families, and 306 genera. Among them, the predominant genera were Rhodococcus and Ralstonia, and their relative abundances were 19.25% and 13.52%, respectively. Root endophytic bacteria were represented by 9 phyla that mainly comprised 19 classes, 44 orders, 82 families, and 140 genera. Among them, the predominant genera were Enterobacter and Escherichia, and their relative abundances were 81.13% and 10.89%, respectively. Seventy-eight of the OTUs were represented in all the rice endophytic samples. Actinobacteria were strongly associated with other bacteria. The higher species abundance of root bacterial endophytic community could regulate various metabolic networks compared to the stem and leaf.[Conclusion] The diversity of bacterial endophytic community associated to rice plants has important ecological significance.

Key words:diversity;bacterial endophytes community;rice different tissues;high-throughput sequencing technology;microbial ecology