Fungal plant pathogens produce more than 70% of all major crop diseases and destroy 15% of global agricultural production through yield losses and mycotoxin contamination, making them by far the most harmful class of plant pathogens. Fusarium is a cosmopolitan genus of filamentous ascomycete fungi that includes many toxin-producing plant pathogens of agricultural importance . Mycotoxin contamination of agricultural products makes them unsuitable for food or feed.
As phytopathogens, fusaria employ a broad range of infection strategies and host specificity varies among Fusarium species. The ubiquitous soil-borne F. oxysporum causes vascular wilt disease in over 100 different plant species and it is also an emerging pathogen of humans that can cause invasive infections in immunocompromised patients .
Research in our laboratory focuses on secondary metabolites produced by endophytic fungi, which live in plants without provoking disease symptoms. We showed that the endophyte Paraconiothyrium variabile, when co-cultured with F. oxysporum, has an antagonistic growth effect on the phytopathogen and actively suppresses the production of beauvericin, a mycotoxin of F. oxysporum involved in virulence . Our study also showed that the oxylipin 13-oxo-9,11-octadecadienoic acid (13-oxo-ODE) is overproduced during this antagonistic interaction and is responsible for over 50% of beauvericin suppression.
The genome sequencing of the endophyte P. variabile is in progress and we have already established a genetic transformation system in this fungus. Using molecular approaches, we are currently trying to elucidate the biosynthesis of the 13-oxo-ODE oxylipin in P. variabile and its mode of action on beauvericin regulation in F. oxysporum.El texto completo de este artículo está disponible en PDF.