A Metabolomic Study Highlights Fungal Adaptation and (R)-Mellein Production

The pathogenic fungus Neofusicoccum parvum, responsible for grapevine trunk diseases, produces specialized metabolites such as (R)-mellein, a phytotoxic compound linked to virulence. This study by Restrepo-Leal et al. compares the metabolomes of two wild-type strains (Bt67 and NpB) and a UV mutant (UV9) cultured with or without grapevine cane powder. The results show that wild-type strains reduce (R)-mellein production but increase metabolite diversity when exposed to plant tissue, suggesting metabolic reprogramming. In contrast, the UV9 mutant, impaired in host signal detection, maintains high (R)-mellein production.

Centrifugal partition chromatography (CPC) and preparative HPLC enabled the purification of 303 mg of (R)-mellein at 99% purity, facilitating future research on its role in infection. Among the metabolites induced by grapevine wood, phytohormone-related compounds (e.g., indole-3-lactic acid) and microbial communication molecules (tryptophol, N-acetyltyramine) were identified, revealing complex host-pathogen interactions and microbial competition strategies.

This study underscores the importance of specialized metabolites in N. parvum pathogenicity and identifies potential targets for disease management.

Reference:
Restrepo-Leal et al. Journal of Agricultural and Food Chemistry, 2025. DOI: 10.1021/acs.jafc.5c03139

Contact: Ludovic Besaury (ludovic.besaury@univ-reims.fr)