Poster Presentation International Plant Molecular Biology Conference 2024

Control of aflatoxin contamination in maize by host-induced silencing of Aspergillus flavus genes essential for its growth and/or toxin production (#64)

Kanniah Rajasekaran 1
  1. USDA-Agricultural Research Service, New Orleans, LOUISIANA, United States

Aflatoxin contamination in maize, a major food and feed crop, caused by Aspergillus flavus - a saprophytic fungus, not only reduces marketability but also adversely influences human and animal health worldwide due to severe carcinogenicity. The most efficient and practical approach to reduce pre-harvest contamination in maize is by development of resistant lines through molecular breeding. Host-induced RNAi-mediated gene silencing (HIGS) of key A. flavus genes responsible for its growth, infection, and toxin production by down-regulation of specific genes has been successfully demonstrated. Transgenic RNAi corn lines capable of shutting down key fungal genes needed for growth (alpha-amylase, p2c or polygalacturonase, alkaline protease) and/or aflatoxin production (aflatoxin biosynthesis pathway genes and global regulators such as aflC, aflS, aflM, aflP, aflR, veA, nsdC) demonstrated significant reductions in aflatoxin levels in kernels. Some of these lines have been evaluated under field conditions to demonstrate significant resistance to aflatoxin contamination. The resistance trait has been successfully transferred to commercial maize lines. A detailed description of our research efforts to reduce aflatoxin contamination levels to minimize its toxic effects in global food and feed supply will be presented.