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ARS Home » Southeast Area » New Orleans, Louisiana » Southern Regional Research Center » Food and Feed Safety Research » Research » Research Project #430862

Research Project: Use of Classical and Molecular Technologies for Developing Aflatoxin Resistance in Crops

Location: Food and Feed Safety Research

Project Number: 6054-42000-025-00-D
Project Type: In-House Appropriated

Start Date: Jun 14, 2016
End Date: Jun 13, 2021

Objective:
Objective 1. Develop aflatoxin-resistant corn with enhanced resistance traits against other mycotoxins and drought tolerance. Identify gene regulatory factors, networks and pathways related to resistance-associated proteins (RAPs). These data are then transferred to others to assist in selection by marker-assisted breeding. Objective 2. Identify resistance associated protein (RAPs) genes from corn and cotton using transcriptomic analyses of the Aspergillus flavus-host plant interaction and evaluate for control of fungal growth and aflatoxin contamination. Objective 3. Develop and evaluate transgenic corn and cotton containing over-expressed identified RAP genes (Objectives 1 and 2) or with RNA interference (RNAi)-based silencing of Aspergillus flavus genes critical to growth and aflatoxin production. Objective 4. Advance and license the rapid, non-destructive hyperspectral imaging technology; develop and evaluate instruments suitable for different user platforms.

Approach:
Aflatoxin contamination in crops such as corn, cottonseed, peanut, and tree nuts caused by Aspergillus (A.) flavus is a worldwide food safety problem. Aflatoxins are potent carcinogens and cause enormous economic losses from destruction of contaminated crops. Utilizing resistant germplasm against A. flavus growth and aflatoxin contamination is the most practical solution for pre-harvest control, the overall goal of this project plan. To this end, we plan to elucidate the complex, multi-genic resistance mechanisms in corn identified in resistant genotypes bred through a collaborative program. We will understand the molecular basis of seed-based resistance through transcriptomic analysis of the corn-A. flavus interaction allowing identification of genes and networks correlated with resistance for use in marker-assisted breeding. RNA interference technology will be used to a) determine the roles and contribution of selected corn genes to overall resistance; and b) to target genes critical to A. flavus growth and toxin production to generate corn varieties with enhanced resistance. Resistance genes identified from transcriptomic analysis of the A. flavus-cottonseed interaction, along with identified corn resistance genes will be over-expressed in cotton to achieve enhanced resistance. Finally, instrumentation for non-destructive, hyperspectral imaging detection will be refined and modified to address practical applications suitable for different user-specified platforms. The proposed research will result in development of cotton and corn germplasm with enhanced resistance to A. flavus growth and aflatoxin contamination. Information and material generated from this research will benefit the scientific community, stakeholder groups, food and feed safety regulatory agencies and consumers, both nationally and internationally.