Scientists Identify Gene Defect in Herbicide-Sensitive Corn

Herbicides registered for use in sweet corn kill unwanted plants while leaving the crops unharmed, thanks to protective enzymes in corn that rapidly degrade the chemicals. This is not the case, however, for several sweet corn hybrids that harbor a genetic defect that impedes the action of the protective enzymes. The defect causes herbicides to remain in the hybrids, resulting to plants with stunted growth or poor yield.

Scientists from the US Department of Agriculture Agricultural Research Service (ARS) and University of Illinois have identified the cause of herbicide sensitivity in hybrid corns. They found out that a defect in the cytochrome P450 gene, or a very closely linked gene, results in damage to plants from five distinct herbicide classes. The cytochrome P450 gene also regulates the metabolism of the herbicides nicosulfuron and bentazon. Evaluations of sweet corn hybrids and inbred lines revealed that the faulty gene is widespread in both processing and fresh-market types of sweet corn grown throughout North America. With the defect identified, it is now possible to eliminate herbicide-sensitivity from the germplasm by selective breeding.

For more information read http://www.ars.usda.gov/is/pr/2008/080521.htm