Location: Toxicology & Mycotoxin ResearchTitle: Chemical warfare: The mycotoxins aflatoxin and fumonisin govern Aspergillus flavus-Fusarium verticillioides interactions.
Submitted to: American Phytopathological Society
Publication Type: Abstract Only
Publication Acceptance Date: 4/15/2021
Publication Date: N/A
Technical Abstract: Contamination of maize by mycotoxins affects food safety worldwide. Mycotoxin consumption can lead to a variety of life-threatening health problems for animals and humans. Consequently, there is a large economic cost associated with mycotoxin contamination, including quality-price downgrades and even complete crop loss from required destruction. Two mycotoxins commonly contaminating maize, aflatoxin and fumonisin, are produced by the plant pathogens Aspergillus flavus (Af) and Fusarium verticillioides (Fv) respectively. Multiple studies/surveys have found these fungi co-colonizing maize in the field thy have not examined their direct interaction in detail. In this study, we investigated in vitro interactions between Af and Fv by employing wild-type and mycotoxin non-producing mutant strains. We show using these strains that fumonisin inhibits the growth of Af, while, in contrast, aflatoxin did not impact the growth of Fv. However, when confronted, the ability of each fungus to produce its primary mycotoxin correlates to reduced mycotoxin production by the other species. The responses were also positionally variable with Af demonstrating a reduction in aflatoxin proximal to a fumonisin producing Fv strain, while fumonisin production was suppressed colony-wide in response to an aflatoxin producing Af. This work gives insights into the ecological role of mycotoxins as well as their potential to be used in fungal-fungal communication. The interactions observed here suggest that, in co-colonized ears, each species likely reduces the level of mycotoxin contamination by the other.