Transcriptional responses and reduction in carpogenic germination of Sclerotinia sclerotiorum exposed to volatile organic compounds of Trichoderma azevedoi

Abstract

The disease caused by Sclerotinia sclerotiorum is known as white mold, sclerotic rot or sclerotic wilt. The use of antagonistic fungi, such as those of the genus Trichoderma, has been shown to be an option to control white mold. Until the completion of this manuscript, only one study showed changes in transcriptional response to Trichoderma volatile organic compounds (VOCs) in S. sclerotiorum. The aim of this study was to identify alterations in the expression profile of S. sclerotiorum CEN1147 exposed to the VOCs of T. azevedoi CEN1241. Tests were carried out in the laboratory using inverted Petri dish tests, followed by RNA extraction and RNA-Seq analysis. VOCs inhibited mycelial growth of the pathogen by approximately 32% compared to control. Approximately 1443 transcripts were differentially expressed between the control and treatment groups. Within those with the highest fold changes, we highlight 25 transcripts divided into 8 functional categories related to melanin production, cell wall, defense, cell respiration, transmembrane transport, pathogenicity, vegetative incompatibility, and stress response. It was also demonstrated that the VOCs of T. azevedoi CEN1241 were able to reduce the carpogenic germination of S.sclerotiorum. These results indicate the complexity of the responses occuring during biological control by Trichoderma and reinforce the potential of VOCs emitted by Trichoderma for biotechnological application in the control of S.sclerotiorum.