Genetic traits may mingle to boost corn production

Texas AgriLife Research scientists plan to study two corn traits that will likely improve US corn quality and yields.

Drought tolerance and aflatoxin resistance are the targets of the USDA-funded four-year project. The idea is to identify the drought- and aflatoxin-related genes and apply them in corn breeding.

Plant pathologist Dr. Michael Kolomiets said they plan to use basic knowledge learnt from previous studies and translate that through breeding corn for drought tolerance and aflatoxin resistance.

The "basic knowledge" stems from discoveries Kolomiets has made in researching a 13-member family of genes called LOX, or lipoxygenase. He said one LOX family member is connected to a plant's drought response while another is linked to aflatoxin development.

One of the LOX genes appeared to be "hijacked" when droughty conditions are ripe for the Aspergillus fungi to ride into the plant with its toxins. Yet another member of the gene family is the reason for plant aging and death once the plant is under severe drought stress.

Lipids - the fats and oils in plants like corn, soy, peanuts, tree nuts and cotton - are sought out by pathogens like fungi. So preventing the gene hijacking - via a mutation of the gene that has been shut down - will help corn plants avoid problems with these weather-related maladies, said Kolomiets.

Drought is a recurring problem for corn producers - especially in the southern US and throughout other parts of the world. Aflatoxin, which becomes prevalent in drought years, is a serious issue because it renders corn inedible for humans as well as for many livestock, depending on the content level. Both of these concerns cause a blow to the economy when the corn supply is cut by lower yields or poor quality, said the researchers.

Loss in Texas from mycotoxins - mostly aflatoxin - was US$13 million in 2008, the highest in the nation, according to the researchers.