Location: Mycotoxin Prevention and Applied Microbiology Research
Project Number: 5010-42000-053-000-D
Project Type: In-House Appropriated
Start Date: Jan 5, 2021
End Date: Jan 4, 2026
Objective:
Objective 1: Define diversity of mycotoxin-producing Fusarium species. [C1, PS1, PS2]
Sub-objective 1.A: Elucidate phylogenetic diversity, mycotoxin potential, and pathogenicity to cereals of fungi in the F. tricinctum species complex.
Sub-objective 1.B: Identify genomic and phenotypic differences in collections of F. proliferatum and F. verticillioides isolates to aid discovery of targets for control of fumonisins in corn.
Objective 2: Identify targets to reduce fumonisin contamination in corn. [C1, PS1, PS2, PS5]
Sub-objective 2.A: Determine whether the corn zmCRR1 protein contributes to resistance to fumonisin contamination.
Sub-objective 2.B: Identify corn genes encoding papain-like cysteine proteases involved in fumonisin contamination to aid genomics-assisted breeding.
Sub-objective 2.C: Reduce fumonisin contamination in corn by engineering kernel-specific expression of RNAi targeting the fumonisin biosynthetic gene FUM1.
Sub-objective 2.D: Determine how corn oxylipins control fumonisin production in F. verticillioides.
Sub-objective 2.E: Determine whether the killer meiotic drive element SkK can be used to drive biased transmission of a gene that blocks fumonisin production in F. verticillioides.
Approach:
Fusarium species are fungi with potentially the greatest negative impact on agriculture. This is because of their collective abilities to produce mycotoxins and cause destructive diseases in crops, including the important cereals: corn, wheat, and rice. The Fusarium mycotoxins fumonisins and trichothecenes are among the mycotoxins of most concern to food and feed safety due to their toxicity and frequent occurrence in crops. However, Fusarium species produce other mycotoxins whose effects on food and feed safety are poorly understood. In the U.S., harmful impacts of mycotoxins on health are mitigated by removing contaminated grain from food/feed supply chains. Despite these efforts, however, the toxins continue to cause billions of dollars in agricultural losses. This project plan addresses knowledge gaps that hinder control of mycotoxins caused by two groups of Fusarium: the Fusarium tricinctum species complex (FTSC), which includes multiple species that cause head blight of small-grain cereals and produce multiple mycotoxins; and the F. fujikuroi species complex, specifically Fusarium proliferatum and Fusarium verticillioides, which are the primary causes of fumonisin contamination in corn. The proposed research has two objectives: i) define diversity of mycotoxin-producing Fusarium species, specifically members of the FTSC, F. proliferatum, and F. verticillioides; and ii) identify targets to reduce fumonisins in corn. To address the first objective, we propose to elucidate variation in genome sequences, mycotoxin production, and pathogenicity within and among Fusarium species. This will aid development of broadly effective control practices for Fusarium mycotoxins. To address the second objective, we propose to identify corn and Fusarium proteins/genes that can be used to enhance breeding or engineering strategies aimed at reducing fumonisin contamination. To address the second objective, we also propose to develop fumonisin reduction methods based on two biological phenomena: RNA interference and meiotic drive elements. The research accomplishments will aid efforts to reduce mycotoxin contamination in corn and other cereal crops, and will benefit growers, processors, regulatory agencies, and ultimately American consumers.
