Transgenic Expression of Antimicrobial Synthetic Peptide AGM182 in Developing Corn Ears Confers Pre-Harvest Resistance In Planta to Aspergillus flavus and Aflatoxin Contamination

Aflatoxin contamination of corn (Zea mays) caused by Aspergillus flavus is a major concern in the US and globally due to its acute toxicity and carcinogenicity in humans and livestock. Transgenic expression of synthetic peptides, which have been modified for greater antimicrobial activity and stability, is a promising approach to mitigating aflatoxin contamination in crops. In this study, corn that was modified with the synthetic peptide AGM182, derived from tachyplesin-1, was tested in two inoculated greenhouse trials for resistance to Af70-GFP, an A. flavus strain that expresses green fluorescent protein. A 25-50% reduction in conidia on corn kernels was observed, up to 60% reduction of internal kernel fungal colonization (GFP fluorescence), and 50% reduction in aflatoxin contamination for corn expressing AGM182 from wildtype Hi-II corn. Our results reveal that incorporating AGM182 and other synthetic antimicrobial peptides traits can reduce aflatoxin contamination in corn.