根际微生物组介导的解淀粉芽孢杆菌FH-1对水稻的促生机制

Rhizosphere microbiome mediated growth-promoting mechanisms of Bacillus amyloliquefaciens FH-1 on rice

摘要:

[目的] 利用大田实验和分子生物学技术进行水稻促生菌解淀粉芽孢杆菌（Bacillus amyloliquefaciens）FH-1改良土壤微生物组的研究，以初步了解解淀粉芽孢杆菌FH-1的促生机理，为微生物肥料的研制和应用提供理论基础。[方法] 设置菌剂FH-1处理（FH）和空白对照（CK）的水稻大田实验，测定植物生理性状包括水稻株高、根长和穗长，并统计水稻的穗数、单穗粒数和千粒重；利用实时荧光定量PCR技术分析水稻根际土壤细菌的数量；利用16S rRNA基因高通量测序解析水稻根际土壤微生物的物种组成；进一步通过Pearson相关统计分析研究水稻-土壤-微生物之间的相互作用。[结果] 与空白对照（CK）相比，菌剂FH-1处理（FH）中植物的株高、根长、穗长、单株穗数、单穗粒数、千粒重显著提高，但是土壤理化性质无显著性差异。菌剂FH-1处理（FH）对细菌总数量无显著影响，但是可显著降低微生物α多样性，显著提高土壤中的γ-变形菌纲、绿弯菌门，显著降低土壤中的β-变形菌纲、疣微菌门的丰度（P<0.05），LEfSe分析显示菌剂FH-1处理（FH）土壤中富集的微生物有19个，主要包括绿弯菌门、PAUC34f、S035、4-29、芽孢杆菌纲、芽孢杆菌目、浮霉菌纲、A31、H39、S0208、Gemmatales、红螺菌目、HOC36、AKIW659、0319-6A21、生丝微菌科、红螺菌科、EB1003、HB2-32-21。相关性分析结果表明施加菌剂FH-1及其富集的相关物种与水稻植株的各个特性呈正相关。[结论] 在水稻大田种植中施加微生物菌剂FH-1，可显著促进水稻生长，对土壤理化性质无显著影响，但可以显著改变微生物群落结构和功能，富集有益物种。因此我们推测解淀粉芽孢杆菌FH-1是通过调控根际微生物群落结构和功能促进水稻生长和发育。

关键词:Bacillus amyloliquefaciens FH-1;植物促生菌;水稻;根际微生物组;高通量测序

Abstract:

[Objective] A field experiment and molecular biology techniques were used to study the improvement of rhizosphere microbiome by Bacillus amyloliquefaciens FH-1, in order to understand the promoting mechanism of B. amyloliquefaciens FH-1 in soil. [Methods] The rice field experiments with the inoculation FH-1 treatment (FH) and blank control (CK) were set up. The physiological traits of rice and soil properties were determined. The number of rhizosphere bacteria was quantified by real-time fluorescent quantitative PCR. High throughput sequencing technology of 16S rRNA gene was used to analyze rhizosphere microbiome. The interaction among rice, soil and microbe was analyzed by Pearson correlation analysis. [Results] Compared to the control, the plant height, root length, spike length, panicles per plant, grain number per spike, and thousand-grain weight of rice were significantly increased by FH. There was no significant difference in soil properties and bacteria number between FH and the control. The FH significantly increased γ-Proteobacteria and Chloroflexi while significantly decreased β-Proteobacteria and Actinobacteria in soil. LEfSe analysis showed that there were 19 microorganisms enriched in FH. Correlation analysis showed that Bacillus and enriched species were positively correlated with rice plant. [Conclusions] We speculated that Bacillus amyloliquefaciens FH-1 promoted rice growth by regulating rhizosphere microbial community structure and function.

Key words:Bacillus amyloliquefaciens FH-1;plant growth-promoting bacteria;rice;rhizosphere microbiome;high-throughput sequencing