Abstract

Terpenes constitute a major part of secondary metabolites secreted by plants in the rhizosphere. However, their specific functions in fungal-plant interactions have not been investigated thoroughly. In this study we investigated the role of monoterpenes in interactions between oilseed rape (Brassica napus) and the soilborne pathogen Verticillium longisporum. We identified seven monoterpenes produced by B. napus, and production of alpha-pinene, beta-pinene, 3-carene, and camphene was significantly increased upon fungal infection. Among them, beta-pinene was chosen for further analysis. Transcriptome analysis of V. longisporum on exposure to beta-pinene resulted in identification of two highly expressed pleotropic drug transporters paralog genes named VlAbcG1a and VlAbcG1b. Overexpression of VlAbcG1a in Saccharomyces cerevisiae increased tolerance to beta-pinene, while deletion of the VlAbcG1a homologous gene in Verticillium dahliae resulted in mutants with increased sensitivity to certain monoterpenes. Furthermore, the VlAbcG1a overexpression strain displayed an increased tolerance to beta-pinene and increased virulence in tomato plants. Data from this study give new insights into the roles of terpenes in plant-fungal pathogen interactions and the mechanisms fungi deploy to cope with the toxicity of these secondary metabolites.

Keywords

ABC-transporters; Brassica napus; monoterpenes; soilborne pathogen; beta-pinene

Published in

Molecular Plant Pathology
2022, volume: 23, number: 2, pages: 291-303
Publisher: WILEY

Authors' information