Location: Food and Feed Safety Research
Project Number: 6054-42000-027-013-A
Project Type: Cooperative Agreement
Start Date: May 4, 2026
End Date: Sep 30, 2029
Objective:
With the long-term goal of developing Aspergillus flavus resistant maize lines free from aflatoxin contamination, the proposed project is envisioned with the following objectives:
1) To develop gene edited maize lines for target genes identified through our previous project efforts.
2) To screen the gene edited lines for their resistance against A. flavus infection and establishment in vitro.
3) To test the homozygous gene edited clean mutant lines for resistance to A. flavus infection under field conditions.
Approach:
Genes to be used for editing have been identified from the catalog of genes identified from our previously funded cooperative projects. DNA variations in these candidate aflatoxin-resistance associated genes between known resistant (e.g., as TZAR102) vis-à-vis susceptible (e.g., Va35) maize varieties will be assessed to identify target sites for gene editing. Based on the target sites, strategies for knock-out or base-editing or other appropriate editing strategies will be determined. Plasmid vectors will be constructed using publicly available plasmids (source: Addgene) and plasmids available with the PI at LSUAC. Guide RNAs will be designed and cloned into vectors such as pRGEB31, pDirect_21A, pH-nCas9-PBE, etc. with appropriate Cas protein using optimized promoters. Editing constructs will be introduced to known A. flavus susceptible but established commercial varieties using Agrobacterium tumefaciens-mediated transformation to create deletion and/or base change mutations in target genes. Gene edited maize lines with desirable homozygous mutation with no off-target mutation and free from other unwanted vector components will be isolated from segregating lines. These clean lines will be bio-assayed for A. flavus resistance and evaluation for other agronomic traits.