Fusarium verticillioides genetics contribute to variability in Fumonisin Risk in maize

Authors: Opoku, Joseph; Busman, Mark; Castano-Duque, Lina; Proctor, Robert; Kim, Hye-Seon; Vaughan, Martha

Submitted to: Frontiers in Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/9/2026
Publication Date: 3/3/2026
Citation: Opoku, J., Busman, M., Castano-Duque, L.M., Proctor, R., Kim, H., Vaughan, M.M. 2026. Fusarium verticillioides genetics contribute to variability in Fumonisin Risk in maize. Frontiers in Microbiology. https://doi.org/10.3389/fmicb.2026.1713439.
DOI: https://doi.org/10.3389/fmicb.2026.1713439

Interpretive Summary: Fumonisins are harmful toxins made by certain fungi that grow on corn. These toxins can make the grain unsafe to eat and cause big financial losses for farmers. To help prevent this, scientists use prediction tools to warn farmers when the risk of contamination is high. But current tools don’t include enough information about how genetic variability of fungi affects growth and fumonisin production under different conditions. To improve these tools, scientists from the USDA in Peoria, Illinois, and New Orleans, Louisiana, studied how fungal genetic variability and temperature affect growth and toxin production. They found that the risk of fumonisin contamination depends on a mix of factors including fungal strain genetics, the temperature, and the interaction that impact the rate at which the fungus grows and toxins are made. This research shows that one-size-fits-all prediction models may not be good enough. Instead, we need more precise tools that consider both local fungal variability and environmental conditions. These findings will help build better food safety systems that protect people’s health and help farmers grow safer, more profitable crops.

Technical Abstract: Fusarium verticillioides is a major fungal pathogen of maize and a primary producer of fumonisins which are mycotoxins that threaten food safety and animal health. This study examined the influence of F. verticillioides genetic diversity on the development of fumonisin risk index. Nineteen strains were whole genome-sequenced and analyzed phylogenetically, from which five genetically diverse strains were selected for detailed assessment. Cultures were incubated at 10–40°C for 2, 5, and 8 days, and data were analyzed using a full factorial model with least squares means and Tukey’s HSD tests. Growth rates were modeled using the Baranyi growth model, and temperature effects on the rate were evaluated with the Ratkowsky equation. Growth occurred over a broader temperature range (15–35°C) than fumonisin production (optimal at 20–30°C; some strains up to 35°C). Strain 66787 initiated fumonisin synthesis earlier than others, while 66476 reached the highest levels at later stages. Biomass and fumonisin levels were positively correlated (R²=0.524 overall; R²=0.78 at 30°C), though the strength of this relationship varied with temperature. Fumonisin analog profiles were strain-specific: 66476 predominantly produced FB2 and FB4, whereas 66786 favored FB1 and FB3. These results demonstrate that fumonisin risk is shaped by a complex interplay of strain genetics, environmental conditions, and toxin biosynthetic regulation. The strain-dependent differences in growth kinetics, toxin onset, and analog composition underscore the need for predictive risk models that integrate both environmental and genetic parameters to improve early-warning systems and targeted mitigation strategies in maize production and storage.