Metagenomics of maize-associated rhizospheric soil samples with seed bacterization with Azospirillum brasilense Ab-V5 in a dilution-to-extinction of native microbial diversity. Meta-omics integration approach reveals the effect of soil native microbiome diversity in the performance of inoculant Azospirillum brasilense

We aimed to characterize maize bulk soil and rhizosphere microbiomes in irradiated soil (IS) and a native soil (NS) microbial community gradient (dilution-to-extinction) with Azospirillum brasilense Ab-V5, a PGPB commercial inoculant to maize. Our hypothesis was that plant growth promotion efficiency is a result of PGPB niche occupation and persistence according to the holobiont conditions. The effects of Ab-V5 and NS microbial communities were evaluated in microcosms by a combined approach of microbiomics (species-specific qPCR, 16S rRNA metataxonomics and metagenomics) and plant phenomics (conventional and high-throughput methods).

本研究旨在针对接种商用玉米植物促生细菌（Plant Growth-Promoting Bacteria，PGPB）巴西固氮螺菌Ab-V5的体系，解析辐照土壤（IS）与采用稀释至灭绝法构建的原生土壤（NS）微生物群落梯度中，玉米非根际土壤及根际土壤的微生物组特征。本研究提出的假说为：植物促生效率取决于植物促生细菌在全共生体（holobiont）条件下的生态位定殖与存活持久性。本研究通过微缩培养体系，结合微生物组学（物种特异性定量聚合酶链反应、16S rRNA宏分类组学与宏基因组学）与植物表型组学（常规方法及高通量方法）的联合分析策略，评估了Ab-V5与NS微生物群落的作用效应。