AUTHOR=Kong Wei-Liang , Ni Hang , Wang Wei-Yu , Wu Xiao-Qin 

TITLE=Antifungal effects of volatile organic compounds produced by Trichoderma koningiopsis T2 against Verticillium dahliae

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.1013468

DOI=10.3389/fmicb.2022.1013468

ISSN=1664-302X

ABSTRACT=<p>Volatile organic compounds (VOCs) produced by microorganisms are considered promising environmental-safety fumigants for controlling soil-borne diseases. <italic>Verticillium dahliae</italic>, a notorious fungal pathogen, causes economically important wilt diseases in agriculture and forestry industries. Here, we determined the antifungal activity of VOCs produced by <italic>Trichoderma koningiopsis</italic> T2. The VOCs from <italic>T. koningiopsis</italic> T2 were trapped by solid-phase microextraction (SPME) and tentatively identified through gas chromatography–mass spectrometry (GC/MS). The microsclerotia formation, cell wall-degrading enzymes and melanin synthesis of <italic>V. dahliae</italic> exposed to the VOC mixtures and selected single standards were examined. The results showed that the VOCs produced by strain T2 significantly inhibited the growth of <italic>V. dahliae</italic> mycelium and reduced the severity of <italic>Verticillium</italic> wilt in tobacco and cotton. Six individual compounds were identified in the volatilome of <italic>T. koningiopsis</italic> T2, and the dominant compounds were 3-octanone, 3-methyl-1-butanol, butanoic acid ethyl ester and 2-hexyl-furan. The VOCs of strain T2 exert a significant inhibitory effect on microsclerotia formation and decreased the activities of pectin lyase and endo-β-1,4-glucanase in <italic>V. dahliae</italic>. VOCs also downregulated the <italic>VdT3HR</italic>, <italic>VdT4HR</italic>, and <italic>VdSCD</italic> genes related to melanin synthesis by 29. 41-, 10. 49-, and 3.11-fold, respectively. Therefore, <italic>T. koningiopsis</italic> T2 has potential as a promising biofumigant for the biocontrol of <italic>Verticillium</italic> wilt disease.</p>