An Integrated Insight into the Relationship between Soil Microbial Community and Tobacco Bacterial Wilt Disease

Hongwu Yang,Delong Meng,Yili Liang,Hongwei Liu,Huaqun Yin,Jin Hu,Xueduan Liu,Yunhua Xiao,Juan Li,Yabing Gu

doi:10.3389/fmicb.2017.02179

Abstract

The soil microbial communities play an important role in plant health, however, the relationship between the below-ground microbiome and above-ground plant health remains unclear. To reveal such a relationship, we analyzed soil microbial communities through sequencing of 16S rRNA gene amplicons from 15 different tobacco fields with different levels of wilt disease in the central south part of China. We found that plant health was related to the soil microbial diversity as plants may benefit from the diverse microbial communities. Also, those 15 fields were grouped into ‘healthy’ and ‘infected’ samples based upon soil microbial community composition analyses such as unweighted paired-group method with arithmetic means (UPGMA) and principle component analysis, and furthermore, molecular ecological network analysis indicated that some potential plant-beneficial microbial groups, e.g., Bacillus and Actinobacteria could act as network key taxa, thus reducing the chance of plant soil-borne pathogen invasion. In addition, we propose that a more complex soil ecology network may help suppress tobacco wilt, which was also consistent with highly diversity and composition with plant-beneficial microbial groups. This study provides new insights into our understanding the relationship between the soil microbiome and plant health.

Highlights

Soil borne pathogens attack crops and causing huge yield losses
We investigated the soil microbial community using 16S rRNA gene sequencing, constructed molecular ecological networks based on random matrix theory, analyzed network properties and inferred the key microorganisms in these networks
Multiple soil factors are responsible for bacterial wilt infection as the soil microbiome plays an important part of tobacco wilt severity

Summary

Introduction

Soil borne pathogens attack crops and causing huge yield losses. Bacterial wilt disease, caused by Ralstonia, can infect Solanaceae crops (e.g., tobacco, tomato, egg plants, etc.) with large scale crop damage world wide, and many efforts have been made to control this disease (Janvier et al, 2007). A number of factors have an effect on soil borne plant pathogen infections including the soil microbiome (Pieterse and Dicke, 2007; Delgado-Baquerizo et al, 2016). Because controlling plant pathogens by microbes is a sustainable and chemical-free approach, diseasesuppressive soils with beneficial microbes have been developed for biocontrol of plant diseases. The incidence or severity of disease is often lower in suppressive soils in comparison with that in surrounding soils (Cook and Baker, 1983)

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