Weed Triggers Plants to Self Destruct

Spotted knapweed, a highly invasive thistle, releases a natural herbicide that kills native plants.

Scientists have always thought that invasive plants take over other natives by being more efficient in their use of resources. But the spotted knapweed has a truly homicidal use of chemistry. Catechin, a chemical released by this plant, was documented by researchers at Colorado State University. A natural herbicide, it causes plants to self-destruct, allowing the spotted knapweed to take over. Jorge Vivanco, Colorado State Department of Horticulture and Landscape Architecture professor says, ?EUR??,,????'??It actually triggers a genetic response within other plants, causing them to create oxidants-free radicals-as well as triggering genes that cause the plant's cells to die, and it's dead in a short period of time.?EUR??,,????'?? The new research combines horticulture, biology, chemistry, weed science and genetics. The spotted knapweed is native to Europe. When soil levels of catechin in Colorado and Europe were compared, catechin levels were four to five times higher than in Europe. Potted plants native to Europe exposed to those same levels of catechin weren't affected. ?EUR??,,????'??There is strong evidence that chemistry can play a role when weeds invade non-native soil,?EUR??,,????'?? said Vivanco. For more information go to: www.colostate.edu