Morphological and protein alterations in Sclerotinia sclerotiorum (Lib.) de Bary after exposure to volatile organic compounds of Trichoderma spp.

Abstract Trichoderma fungi have an important potential for the control of plant diseases due to their various mechanisms of action, such as the production of volatile organic compounds (VOCs). The phytopathogenic fungus Sclerotinia sclerotiorum (Lib.) de Bary causes a disease called white mold, sclerotinia rot or sclerotinia wilt, in several plant species. The objective of this work was to evaluate the mycelial morphology and protein profile of S. sclerotiorum after exposure to VOCs produced by six Trichoderma strains. The assays were performed in the laboratory using inverted plate tests with evaluation of mycelial growth inhibition, microscopic observation of hyphae and MALDI-TOF analysis of S. sclerotiorum protein profile. The best results were obtained from Trichoderma sp. strain CEN1241, with up to 35% inhibition of mycelial growth and the greatest inhibitory effect on the production of differential proteins present in S. sclerotiorum control treatment. All tested Trichoderma strains decreased the width of the pathogen’s hyphae. The diversity of Trichoderma species and VOCs produced by strains of this fungus may enable the development of strategies for the use of such compounds in plant disease control. Considering this biological activity, strain CEN1241 shows potential as a biocontrol agent of white mold.