a metagenomic gene catalogue of soil microbiota from different niches on a farmland of wheat and chickpea, including bulk soil, detritusphere, and rhizospheres. soil microbiome of wheat and chickpea

This study establishes a soil microbial gene catalogue that fully covers the non-redundant genes, based on the bulk soil and living-decaying rhizosphere soil niches in a cropping soil. The soil microbial metagenome was comparatively more complex and diverse (19.8 million genes and 10.2 Gbp total length) than individual samples of ocean water or the human gut. The detritusphere microbiome regulated the composition and function of the rhizosphere microbiome to a greater extent than plant type did: rhizosphere microbiomes in wheat and chickpea were homogenous (65-87% similarity) under simulated no-tillage management but were heterogeneous (3-24% similarity) under tillage, a process that disrupted the detritusphere. Microbial diversity and function were modified by plant root exudation and root channel exploration. This study describes the diversity and function of a high-quality soil microbial metagenome, and the results reveal the importance of the detritusphere microbiome in determining the microbiome of developing root systems, which ultimately govern biomass and grain production.

本研究以耕作土壤中的原状土与活-衰亡根际土壤生态位为研究对象，构建了一套完整覆盖非冗余基因的土壤微生物基因目录。该土壤微生物宏基因组（metagenome）整体复杂度与多样性均高于单个海水样本或人类肠道样本，共包含1980万个基因，总长度达10.2 Gbp。碎屑圈（detritusphere）微生物组对根际微生物组组成与功能的调控作用显著强于植物类型：在免耕模拟管理模式下，小麦与鹰嘴豆的根际微生物组具有65%-87%的较高相似性；而在翻耕模式下，二者根际微生物组相似性仅为3%-24%，翻耕过程会破坏碎屑圈生态。植物根系分泌物与根系通道探索行为可调控微生物多样性与功能。本研究阐明了高质量土壤微生物宏基因组的多样性与功能特征，研究结果揭示了碎屑圈微生物组在调控发育中根系微生物组组成方面的关键作用，而根系微生物组最终会影响作物生物量与籽粒产量。