The Rhizosphere Microbiome of Mikania micrantha Provides Insight Into Adaptation and Invasion.

Lijuan Yin,Hangwei Liu,Fanghao Wan,Wei Fan,Fan Jiang,Hengchao Wang,Yan Zhang,Conghui Liu,Sen Wang,Wanqiang Qian,Yuwei Ren,Bo Liu,Haihong Wang

doi:10.3389/fmicb.2020.01462

Abstract

Mikania micrantha is a noxious invasive plant causing enormous economic losses and ecological damage. Soil microbiome plays an important role in the invasion process of M. micrantha, while little is known about its rhizosphere microbiome composition and function. In this study, we identified the distinct rhizosphere microbial communities of M. micrantha, by comparing them with those of two coexisting native plants (Polygonum chinense and Paederia scandens) and the bulk soils, using metagenomics data from field sampling and pot experiment. As a result, the enrichment of phosphorus-solubilizing bacteria Pseudomonas and Enterobacter was consistent with the increased soil available phosphorus in M. micrantha rhizosphere. Furthermore, the pathogens of Fusarium oxysporum and Ralstonia solanacearum and pathogenic genes of type III secretion system (T3SS) were observed to be less abundant in M. micrantha rhizosphere, which might be attributed to the enrichment of biocontrol bacteria Catenulispora, Pseudomonas, and Candidatus Entotheonella and polyketide synthase (PKS) genes involved in synthesizing antibiotics and polyketides to inhibit pathogens. These findings collectively suggested that the enrichment of microbes involved in nutrient acquisition and pathogen suppression in the rhizosphere of M. micrantha largely enhances its adaptation and invasion to various environments.

Highlights

The rhizosphere is the interface where the complex interactions among soil, microbes, and the host plant are maintained (Philippot et al, 2013)
Many pathogens could not be detected in our data, we found that the pathogens of Fusarium oxysporum (Srinivas et al, 2019) and Ralstonia solanacearum (Genin and Denny, 2012) were enriched in P. chinense and P. scandens rhizosphere compared to M. micrantha rhizosphere (Figure 4A)
Mikania micrantha rhizosphere has a distinct bacteria community structure that is clearly separated from the native plants and the bulk soil

Summary

Introduction

The rhizosphere is the interface where the complex interactions among soil, microbes, and the host plant are maintained (Philippot et al, 2013). The Alnus trabeculosa increased the soil bacterial diversity in the invaded regions (Xueping et al, 2016). Another invasive plant Centaurea maculosa enhanced its competitive ability through enriching mycorrhizal fungi that changes soil nutrient availability (Marler et al, 1999). C. maculosa could reduce local soil pathogens in invaded regions, investing less in unused defense and more into growth to increase competitiveness against natives (Callaway et al, 2004). The invasive tree staghorn sumac changed the structure of soil N2-fixing bacterial communities to enhance soil N availability (Wu et al, 2019). Invasive plants increased the availability of vital nutrients, gaining a competitive advantage, which might be an important contributor to invasion success (Castro-Díez et al, 2014)

Methods

Results

Discussion

Conclusion