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

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.