Tomato Endophytic Bacteria Composition and Mechanism of Suppressiveness of Wilt Disease (Fusarium oxysporum).

Zeyu Zhang,Zengqiang Zhang,Yuquan Wei,Ji Li,Youzhou Liu

doi:10.3389/fmicb.2021.731764

Abstract

Tomato wilt disease, caused by the Fusarium oxysporum is an ever-increasing threat for agricultural production, and unreasonable fertilization and pesticide abuse caused environmental challenge. Increasing evidence suggested that microbiomes or those associated with crops, played key roles on plant health. Plant disease dynamics were affected by multiple biotic and abiotic factors including phytopathogen population density, the genetic type of the pathogen and the host, in particular, the composition and assembly of the host-associated microbiome. However, it was unclear how pathogen invasion interaction and correlate with endophytic bacterial communities in natural field conditions. To study this, we sampled temporally the tomato plants that were exposed to F. oxysporum invasions over one crop season. High-throughput sequencing were performed to explore the correlation between agricultural practice, pathogen invasion, and endophytic microbiota communities. Results showed that pathogen invasion had clear effect on the endophytic and a strong link between increased pathogen densities and reduced abundance of Bacillus sp., which are crucial taxonomy for suppressiveness to F. oxysporum in vitro and in greenhouse condition. In summary, monitoring the dynamics of endophytic bacteria communities and densities of pathogen could thus open new avenue for more accurate disease diagnostics and high-efficiency screening antagonisms methods in the future, and our results will broaden the agricultural view of beneficial microbiota as biological control agents against plant pathogen.

Highlights

Tomato wilt disease, caused by the Fusarium oxysporum, poses a growing threat to agricultural production, and the unreasonable fertilization and pesticide abuse used to control this disease has caused an environmental challenge
Increasing cases illustrate that soil microbiomes or those associated with plants play key roles in plant health (Shen, 1997; Curtis et al, 2004; Chen et al, 2018)
The results showed that concentration of total nitrogen and organic content of the organic greenhouse were significantly higher than those in the conventional greenhouse (p < 0.05, ANOVA, Tukey HSD; Figures 1A–D)

Summary

Introduction

Tomato wilt disease, caused by the Fusarium oxysporum, poses a growing threat to agricultural production, and the unreasonable fertilization and pesticide abuse used to control this disease has caused an environmental challenge. Application of beneficial microbial inoculants can increase crop yields and resist the invasion of pathogens. Suppressive Endophytic Microbiome in Tomato alternative to reduce crop disease level (Mazurier et al, 2009). Various suppressive mechanisms were reported, mainly including the improvement of microbemediated pathogen suppression and inducing the plant immune practice (Hu et al, 2016). Many antagonistic taxonomies including Bacillus spp., Streptomyces spp., Trichoderma spp., and Pseudomonads aeruginosa inhibited soil borne diseases by producing the antibiotics: 2,4-diacetylphloroglucinol, surfactin, fengycin, and antitoxin, etc. Fan et al (2017) found that inoculation of Bacillus subtilis 9407 can suppress the bacterial fruit blotch, for instance, surfactin antibiotic mediated the pathogen suppression Many antagonistic taxonomies including Bacillus spp., Streptomyces spp., Trichoderma spp., and Pseudomonads aeruginosa inhibited soil borne diseases by producing the antibiotics: 2,4-diacetylphloroglucinol, surfactin, fengycin, and antitoxin, etc. (Arrebola et al, 2010; Sandhya et al, 2010; Wang et al, 2019). Fan et al (2017) found that inoculation of Bacillus subtilis 9407 can suppress the bacterial fruit blotch, for instance, surfactin antibiotic mediated the pathogen suppression

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