Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-Saving Fertilizers, Nanjing Agricultural University, Nanjing 210095, Jiangsu, P. R. China.
FEMS Microbiol Ecol. 2019 Oct 1;95(10). doi: 10.1093/femsec/fiz139.
Rhizosphere community assembly is simultaneously affected by both plants and bulk soils and is vital for plant health. However, it is still unclear how and to what extent disease-suppressive rhizosphere microbiota can be constructed from bulk soil, and the underlying agents involved in the process that render the rhizosphere suppressive against pathogenic microbes remain elusive. In this study, the evolutionary processes of the rhizosphere microbiome were explored based on transplanting plants previously growing in distinct disease-incidence soils to one disease-suppressive soil. Our results showed that distinct rhizoplane bacterial communities were assembled on account of the original bulk soil communities with different disease incidences. Furthermore, the bacterial communities in the transplanted rhizosphere were noticeably influenced by the second disease-suppressive microbial pool, rather than that of original formed rhizoplane microbiota and homogenous nontransplanted rhizosphere microbiome, contributing to a significant decrease in the pathogen population. In addition, Spearman's correlations between relative abundances of bacterial taxa and the abundance of Ralstonia solanacearum indicated Anoxybacillus, Flavobacterium, Permianibacter and Pseudomonas were predicted to be associated with disease-suppressive function formation. Altogether, our results showed that bulk soil played an important role in the process of assembling and reassembling the rhizosphere microbiome of plants.
根际群落的组成同时受到植物和土壤的影响，对植物的健康至关重要。然而，目前尚不清楚如何以及在多大程度上可以从土壤中构建具有抑制疾病特性的根际微生物群，并且在使根际对致病微生物具有抑制作用的过程中涉及的潜在因素仍不清楚。在这项研究中，基于将先前在不同发病率土壤中生长的植物移植到一种具有抑制疾病特性的土壤中，探索了根际微生物组的进化过程。我们的研究结果表明，由于原始土壤具有不同的发病率，不同的根际细菌群落被组装起来。此外，移植到根际的细菌群落明显受到第二抑制性微生物库的影响，而不是原始形成的根际微生物群和均匀的非移植根际微生物群的影响，导致病原菌种群显著减少。此外，细菌分类群相对丰度与茄科雷尔氏菌丰度之间的 Spearman 相关性表明，拟杆菌属、黄杆菌属、Permianibacter 和假单胞菌属可能与抑制疾病功能的形成有关。总的来说，我们的研究结果表明，土壤在植物根际微生物组的组装和再组装过程中发挥了重要作用。
