Why do plant-pathogenic fungi produce mycotoxins? Potential roles for mycotoxins in the plant ecosystem

Authors: Sweany, Rebecca; BREUNIG, MIKAELA - Michigan State University; Opoku, Joseph; CLAY, KEITH - Tulane University; SPATAFORA, JOSHEPH - Oregon State University; DROTT, MILTON - University Of Wisconsin; BALDWIN, THOMAS - North Dakota State University; FOUNTAIN, JAKE - Mississippi State University

Submitted to: Phytopathology
Publication Type: Review Article
Publication Acceptance Date: 4/27/2022
Publication Date: 9/22/2022
Citation: Sweany, R.R., Breunig, M., Opoku, J., Clay, K., Spatafora, J.W., Drott, M.T., Baldwin, T.T., Fountain, J.C. 2022. Why do plant-pathogenic fungi produce mycotoxins? Potential roles for mycotoxins in the plant ecosystem. Phytopathology. 112(10):2044-2051. https://doi.org/10.1094/PHYTO-02-22-0053-SYM.
DOI: https://doi.org/10.1094/PHYTO-02-22-0053-SYM

Interpretive Summary: For many plant pathogenic or endophytic fungi, production of mycotoxins which are toxic to humans may present a fitness gain and benefit to the fungus. However, directly linking mycotoxin production and plant disease 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 because it is very deadly and carcinogenic, but the connection between aflatoxin production and pathogenicity is complicated by the success of non-aflatoxigenic isolates in crops. Other toxins directly aid fungi in plants, trichothecenes are important pathogenicity factors and ergot alkaloids limit herbivory and fungal consumption due to insect toxicity. We review an a expert panel discussion held at the American Phytopathological Societies 2021 Plant Health Conference on the diverse roles of mycotoxins in the lifestyles of filamentous fungi.

Technical Abstract: For many plant pathogenic or endophytic fungi, production of mycotoxins which are toxic to humans may present a fitness gain. However, directly linking 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 success of non-aflatoxigenic isolates in crops. Other toxins directly aid fungi in planta, trichothecenes are important pathogenicity factors and ergot alkaloids limit herbivory and fungal consumption due to insect toxicity. We review a panel discussion at Amercian 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), Nectriaceae (Hypocreales).