A clearer picture of corn’s biochemical responses to insect and fungal attacks is emerging, thanks to studies at USDA research facilities in Gainesville, Florida. Taken together, these discoveries add significantly to the existing body of knowledge on corn’s stress-coping mechanisms, and set the stage for novel approaches to improving the grain crop’s insect and disease resistance.

In experiments, physiologically relevant amounts of the newly discovered kauralexin class of phytoalexins inhibited the growth of anthracnose stalk rot by 90 percent. Similarly, zealexins inhibited the growth of the aflatoxin-producing fungus Aspergillus flavus by 80 percent. These maize pathogens cause significant yield loss and fungal-derived toxin contamination issues for U.S. farmers.