Hamid M Imran, Hussain Muzammil, Wu Yunpeng, Zhang Xiaoling, Xiang Meichun, Liu Xingzhong
State Key Lab of Mycology, Institute of Microbiology, Chinese Academy of Sciences, No 3 Park 1, Beichen West Rd., Chaoyang District, Beijing 100101, China.
Department of Plant Pathology, University College of Agriculture, University of Sargodha, Sargodha, 40100, Pakistan.
FEMS Microbiol Ecol. 2017 Jan 1;93(1). doi: 10.1093/femsec/fiw222.
One of the mechanisms of disease suppressiveness in soils is long-term monoculture (LTM) cropping to dissuade pathogen infestation. However, the linkage between monoculturing and microbial community assemblage in the rhizosphere for disease suppression remains unclear. To decipher this potential relationship, soil samples were collected from seven locations in northeastern China, where LTM (6-38 yr) and short-term monoculture (STM ≤ 5 yr) cropping of soybean showed varying degrees of soil suppressiveness to the soybean cyst nematode (SCN; Heterodera glycines). Using high-throughput pyrosequencing to examine bacterial 16S rRNA and fungal ITS1 genes, we observed substantial variation in the species richness and relative abundance of taxa in the rhizosphere across different sampling sites. At the genus level, the genera Pseudomonas, Purpureocillium and Pochonia, which have been documented to suppress SCN in earlier studies, were much more abundant in LTM soils than in STM soils. Moreover, the relative abundance of several bacterial and fungal genera with metabolic, biocidal and parasitic activities was also monitored in the rhizosphere. In this study, we provide additional evidence that plants shift the structural and functional composition of the rhizosphere microbiota to suppress pathogen infection in LTM cropping soils.
土壤中病害抑制的机制之一是长期连作（LTM）种植以阻止病原体侵染。然而，连作与根际微生物群落组合之间在病害抑制方面的联系仍不清楚。为了解析这种潜在关系，从中国东北的七个地点采集了土壤样本，在这些地方，大豆的长期连作（6 - 38年）和短期连作（STM≤5年）对大豆孢囊线虫（SCN；大豆异皮线虫）表现出不同程度的土壤抑制作用。利用高通量焦磷酸测序技术检测细菌16S rRNA和真菌ITS1基因，我们观察到不同采样地点根际分类群的物种丰富度和相对丰度存在显著差异。在属水平上，在早期研究中已证明具有抑制SCN作用的假单胞菌属、淡紫拟青霉属和白僵菌属在长期连作土壤中比短期连作土壤中更为丰富。此外，还监测了根际中几个具有代谢、杀生物和寄生活性的细菌和真菌属的相对丰度。在本研究中，我们提供了额外的证据，证明植物在长期连作土壤中会改变根际微生物群的结构和功能组成，以抑制病原体感染。
