Biotech Updates

Waterhemp's Mechanisms to Thwart Herbicides Uncovered

October 23, 2013

Weed science researchers at the University of Illinois have identified two unique mechanisms in waterhemp that enable this weed to tolerate certain herbicides. In a recently concluded study, scientists described two distinct metabolic detoxification mechanisms that confer resistance to mesotrione (Callisto) and atrazine (Aatrex) in a waterhemp population.

Scientists first looked at herbicide target genes in the waterhemp plants but later on proved that these genes have nothing to do with plant's resistance on herbicide. Instead, they discovered that resistance was due to increased metabolism of mesotrione and atrazine—via P450 enzymes for mesotrione and GST enzymes for atrazine. The faster metabolism of these herbicides in waterhemp resembles the natural mechanism in corn, where the P450 enzymes confer tolerance to Callisto.

See the University of Illinois' news release at