Evaluation of the Biocontrol Potential of Endophytic Fungus Fusarium solani CEF559 against Verticillium dahliae in Cotton Plant.

Feng Wei,Heqin Zhu,Hongjie Feng,Yongqiang Shi,Yun Zhang,Zili Feng,Lihong Zhao

doi:10.1155/2019/3187943

Abstract

Verticillium wilt of cotton, caused by the soilborne pathogen Verticillium dahliae, is one of the most serious diseases of cotton worldwide. Increased concerns about the side effects of synthetic pesticides have resulted in greater interest in developing biocontrol strategies against Verticillium wilt. We evaluated a Fusarium solani CEF559 isolate, obtained from the endosphere of healthy cotton plants, for its biocontrol potential against V. dahliae in vitro and in vivo. In addition to disease assessment, three key genes in the lignin metabolism pathway and four pathogenesis-related (PR) genes were monitored using qRT-PCR. In the laboratory tests, F. solani CEF559 inhibited V. dahliae colony growth by 75% and sporulation by nearly 80% and completely suppressed conidial production. However, volatile metabolites from CEF559 did not affect V. dahliae colony growth. In the greenhouse study, CEF559 significantly reduced wilt development, with a control efficacy greater than 60% when assessed 25 days postinoculation. In a field experiment, CEF559 reduced wilt development, with the efficacy ranting from 30.1% to 56.3%. PR genes and those key genes in the lignin metabolism pathway were transiently upregulated in the cotton roots pretreated with CEF559 when subsequently inoculated with V. dahliae, compared with those plants inoculated with V. dahliae only. Moreover, CEF559 inhibited V. dahliae colonisation of both the roots and hypocotyls. The present results suggest that this cotton endophytic fungal strain, F. solani CEF559, confers protection against V. dahliae.

Highlights

Verticillium dahliae Kleb. is a soilborne plant pathogenic fungus causing wilt disease on more than 200 plant species [1, 2], including cotton (Gossypium hirsutum L.)
Controlling Verticillium wilt in cotton is difficult because of the inaccessibility of V. dahliae propagules during the infection by usual control agents, long-term survival of pathogen propagules in the field, and its broad host range [1, 2, 5]
We studied the expression of pathogenesis-related genes and key genes in the lignin metabolism pathway in cotton against V. dahliae following inoculation with F. solani CEF559

Summary

Introduction

Verticillium dahliae Kleb. is a soilborne plant pathogenic fungus causing wilt disease on more than 200 plant species [1, 2], including cotton (Gossypium hirsutum L.). Controlling Verticillium wilt in cotton is difficult because of the inaccessibility of V. dahliae propagules during the infection by usual control agents, long-term survival of pathogen propagules in the field, and its broad host range [1, 2, 5]. Over the last three decades, many nonpesticide strategies have been evaluated and used to control Verticillium wilt, including crop rotation, biofumigation, soil amendment with green manures or organic materials, anaerobic soil disinfestation, and soil solarization [5, 6]. All these methods have their own specific limitations [5].

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Results

Conclusion