CAS Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.
Department of Microbial Ecology, Netherlands Institute of Ecology, NIOO-KNAW, Wageningen, 6708 PB, The Netherlands.
ISME J. 2019 Mar;13(3):738-751. doi: 10.1038/s41396-018-0300-0. Epub 2018 Oct 27.
Microorganisms associated with roots are thought to be part of the so-called extended plant phenotypes with roles in the acquisition of nutrients, production of growth hormones, and defense against diseases. Since the crops selectively enrich most rhizosphere microbes out of the bulk soil, we hypothesized that changes in the composition of bulk soil communities caused by agricultural management affect the extended plant phenotype. In the current study, we performed shotgun metagenome sequencing of the rhizosphere microbiome of the peanut (Arachis hypogaea) and metatranscriptome analysis of the roots of peanut plants grown in the soil with different management histories, peanut monocropping and crop rotation. We found that the past planting record had a significant effect on the assembly of the microbial community in the peanut rhizosphere, indicating a soil memory effect. Monocropping resulted in a reduction of the rhizosphere microbial diversity, an enrichment of several rare species, and a reduced representation of traits related to plant performance, such as nutrients metabolism and phytohormone biosynthesis. Furthermore, peanut plants in monocropped soil exhibited a significant reduction in growth coinciding with a down-regulation of genes related to hormone production, mainly auxin and cytokinin, and up-regulation of genes related to the abscisic acid, salicylic acid, jasmonic acid, and ethylene pathways. These findings suggest that land use history affects crop rhizosphere microbiomes and plant physiology.
与根系相关的微生物被认为是所谓的扩展植物表型的一部分，它们在获取营养、产生生长激素和抵御疾病方面发挥作用。由于作物从大量土壤中选择性地富集了大多数根际微生物，我们假设农业管理引起的大量土壤群落组成的变化会影响扩展植物表型。在本研究中，我们对花生（Arachis hypogaea）的根际微生物进行了鸟枪法宏基因组测序，并对在不同管理历史、花生单作和轮作土壤中生长的花生根系进行了宏转录组分析。我们发现，过去的种植记录对花生根际微生物群落的组装有显著影响，表明存在土壤记忆效应。单作导致根际微生物多样性减少，几种稀有物种富集，与植物性能相关的性状，如养分代谢和植物激素生物合成的代表性降低。此外，在单作土壤中生长的花生植物的生长显著减少，与与激素产生相关的基因下调有关，主要是生长素和细胞分裂素，与脱落酸、水杨酸、茉莉酸和乙烯途径相关的基因上调。这些发现表明，土地利用历史会影响作物根际微生物组和植物生理学。
