摘要
为了解析具有不同IAA分泌特性的促生菌在植物体内的存在模式及其促生机制。以不可产IAA的植物促生菌Lysinibacillus xylanilyticus CZ29和可产IAA的植物促生菌Rhizobium radiobacter GF12为材料,分别接种于盆栽新中蔬四号番茄幼苗根部,以不接种菌株为对照,采用基于细菌16S rRNA基因V5~V7可变区高通量测序的方法,分析2种不同促生菌在植物根内定植情况及其对生长得到促进的植物根内生菌菌群结构和多样性的影响。结果显示:接种2株促生细菌之后,这2株促生菌在生长得到促进的植物根内的定植量无显著变化,说明促生菌接种的促生长作用并非是通过接种促生菌的定植量增加而实现。且经2种不同促生菌分别接种处理后生长得到促进的番茄根内生菌物种丰富度(Chao1指数)以及细菌多样性(Shannon指数)相对于对照以及相互之间均没有显著差异性(P>0.05),表明这2株促生菌的促生长作用与内生菌菌群丰富度和多样性没有直接联系。基于OTU水平的层次聚类和PLS-DA等分析表明,2株促生菌接种均可显著影响番茄根内生菌菌群结构组成,导致原有的内生菌菌群平衡被打破但其具体的影响不同。其中,接种不可产IAA的植物促生菌L.xylanilyticus CZ29的组别中Roseateles、Sphingobium和Rhizobium益生菌受到显著富集;Myroides、Chryseobacterium、Achromobacter及Strenotrophomonas致害菌被显著抑制(P<0.05)。接种可产IAA的植物促生菌R.radiobacter GF12的组别中各菌属菌群平均丰度与对照相比波动都不明显,菌群结构与对照更为相似并表现出内生菌菌群结构组成更加稳定的特点。因此推测,不可产IAA的植物促生菌L.xylanilyticus CZ29是通过富集益生菌抑制有害菌从而促进植物生长。可产IAA的植物促生菌R.radiobacte GF12则是通过同时上调植物内生菌各主要菌群的丰度从而构建更加稳定的内生菌群增大植物的抗刺激能力及分泌IAA而促进植物生长。
In order to analyze the existence pattern and growth-promoting mechanism of the growth-promoting bacteria with different IAA secretion characteristics in plants,Lysinibacillus xylanilyticus CZ29,the plant growth-promoting bacteria that could not produce IAA,and Rhizobium radiobacter GF12,the plant growth-promoting bacteria that could produce IAA,were used as the materials to be inoculated in the roots of potted tomato seedlings,Xinzhongshu No.4,and the high-throughput sequencing based on the variable region of the bacteria 16S rRNA gene V5-V7 was used to analyze the colonization of the two different growth-promoting bacteria in plant roots whose growth has been promoted and their effect on the structure and diversity of endophytic bacterial flora in plant roots.The results showed that after inoculating the two growth-promoting bacteria,the colonization of the two growth-promoting bacteria in the plant roots whose growth has been promoted did not change significantly,indicating that the growth-promoting effect of the growth-promoting bacteria inoculation was not achieved by increasing the colonization of the inoculated strains.After the inoculation with two different growth-promoting bacteria respectively,there was no significant difference(P>0.05)between the species richness(Chao1 index)and bacterial diversity(Shannon index)of endophytes in tomato roots compared to the control group and between each other,which showed that the growth-promoting effect of these two growth-promoting bacteria was not directly related to the richness and diversity of endophyte flora.The analysis of hierarchical clustering based on OTU level and PLS-DA showed that the inoculation of the two growth-promoting bacteria could significantly affect the composition of the endophyte flora in tomato root,causing the balance of the original endophytic flora to be broken but the specific effects were different.Among them,the probiotics such as Roseateles,Sphingobium and Rhizobium were significantly enriched in the group inoculated with L.xylanilyticus CZ29,the plant growth-promoting bacteria that could not produce IAA;the harmful bacteria such as Myroides,Chryseobacterium,Achromobacter and Strenotrophomonas were significantly inhibited(P<0.05).In the other experimental group inoculated with R.radiobacter GF12,the plant growth-promoting bacteria that could produce IAA,the average abundance of each bacterial genus did not fluctuate significantly compared with the control group,and the microbial community structure was more similar to that of the control group and showed a more stable structure.Therefore,it was hypothesized that L.xylanilyticus CZ29,the plant growth-promoting bacteria that could not produce IAA,promoted the plant growth by inhibiting the harmful bacteria through the enrichment of probiotics,while Rhizobium radiobacter GF12,the plant growth-promoting bacteria that could produce IAA,promoted the plant growth by simultaneously up-regulating the abundance of the main flora of plant endophytes to construct a more stable endophytic flora,thus to increase the anti-irritating ability of plants and secrete IAA.
作者
冯燕辉
熊娟
黎烨
张婷
程林洁
金玲月
张沁怡
蓝灿华
田宝玉
FENG Yan-hui;XIONG Juan;LI Ye;ZHANG Ting;CHENG Lin-jie;JIN Ling-yue;ZHANG Qin-yi;LAN Can-hua;TIAN Bao-yu(College of Life Sciences, Fujian Normal University / Key Laboratory of Cell Stress Responseand Metabolic Regulation, Fuzhou, Fujian 350108, China)
出处
《福建农业科技》
CAS
2021年第6期6-14,共9页
Fujian Agricultural Science and Technology
基金
国家自然科学基金项目(31670125、31660544)
福建省自然科学基金项目(2017J01625)。
关键词
植物促生菌
接种
内生菌
菌群结构
高通量测序
Plant growth-promoting bacteria
Inoculation
Endophyte
Microbial community structure
High-throughput sequencing
