Why Do Plant-Pathogenic Fungi Produce Mycotoxins? Potential Roles for Mycotoxins in the Plant Ecosystem

For many plant-pathogenic or endophytic fungi, production of mycotoxins, which are toxic to humans, may present a fitness gain. However, associations between mycotoxin production and plant pathogenicity or virulence is inconsistent and difficult due to the complexity of these host-pathogen interactions and the influences of environmental and insect factors. Aflatoxin receives a lot of attention due to its potent toxicity and carcinogenicity but the connection between aflatoxin production and pathogenicity is complicated by the pathogenic ability and prevalence of nonaflatoxigenic isolates in crops. Other toxins directly aid fungi in planta, trichothecenes are important virulence factors, and ergot alkaloids limit herbivory and fungal consumption due to insect toxicity. We review a panel discussion at the American Phytopathological Society's Plant Health 2021 conference, which gathered diverse experts representing different research sectors, career stages, ethnicities, and genders to discuss the diverse roles of mycotoxins in the lifestyles of filamentous fungi of the families Clavicipitaceae, Trichocomaceae (Eurotiales), and Nectriaceae (Hypocreales).

Automated summary

The production of mycotoxins in plant-pathogenic or endophytic fungi can provide fitness gain, but the relationship between mycotoxin production and plant pathogenicity or virulence is complex and inconsistent. Aflatoxin, as a highly toxic and carcinogenic mycotoxin, is of particular interest, but its connection to pathogenicity is complicated by the presence of nonaflatoxigenic isolates. Other toxins, such as trichothecenes and ergot alkaloids, play important roles in fungal virulence and herbivore protection. This review summarizes a panel discussion on the diverse roles of mycotoxins in filamentous fungi, involving experts from different research sectors, career stages, ethnicities, and genders.