Corn, or maize, is a staple crop of global economic, industrial, and food security importance. Damage to the growing ears by corn earworm (CEW) can reduce yield, and is thus a major economic burden to farmers. CEW damage to ears can also increase secondary fungal infections and levels of deadly mycotoxins.
In a paper recently published in The Plant Genome, researchers used a new analysis tool assigning CEW resistance genes identified by a genome-wide association study to metabolic pathways to determine which cellular pathways and mechanisms are being used by resistant plants in order to stop CEW from feeding on corn ears. Genes and pathways involved in three separate mechanisms were identified as important.
First, plants that created stronger cell walls seemed to make it harder for worms to eat into kernels. Second, some plants appeared to be making compounds that deter or poison the worm. Third, some of the more resistant plants seemed to be growing faster than susceptible plants, perhaps maturing the ear before the number of hungry worms grew to their peak in the late summer.
This information will help breeders create maize lines that will naturally resist corn earworms without the need for chemical insecticides or GMO (transgenic) technology.