
Read more
about this research in AR magazine. Fungus' Protein Causes Weed
Cells to Self DestructBy Jan Suszkiw February 18, 2000Weeds are notoriously stubborn, but
researchers may be on the verge of turning the pesky plants into their own
worst enemy. Their approach involves spraying the weeds with a natural protein derived
from the soil fungus Fusarium oxysporum. Upon entering natural leaf
openings called stomata, the fungus' protein causes a specific self-defense
mechanism to shift into maximum overdrive. The defense, called a hypersensitive response, normally helps weeds cordon
off infection by instructing nearby cells to self-destruct. But in lab,
greenhouse, and small-scale field trials, spraying the protein causes a mass
cellular suicide instead. In dandelions, for example, this kills the weed's
affected leaves three to 24 hours later. The finding, by Agricultural Research
Service scientists, may open the door to a natural herbicide that farmers,
organic growers or homeowners could spray to check broadleaf weeds like
dandelion, yellow star thistle, pigweed or northern jointvetch. Plant pathologist Bryan Bailey and colleagues are exploring the possibility
at several ARS labs--Biocontrol of Plant
Diseases, Weed Science, and
Soybean and
Alfalfa Research. ARS is USDA's chief
research agency. Bailey's team originally discovered the protein, called Nep1, while trying
to understand how some fusarium fungi cause disease in crops like corn. Studies
begun in 1998 ruled out the protein's role in causing crop disease, but also
revealed its potential as a biological herbicide. The team reports their findings in the January-February issue of Weed
Science. Interestingly, Nep1 only affects broadleaf weeds of the dicot
family with cell receptors that can detect the protein. This suggests it could
be sprayed onto monocot crops like corn, wheat, or even turfgrass without
causing harm. Another possibility is spraying Nep1 to clear away certain cover
crops, like hairy vetch, prior to planting. A longer article about the team's discovery appears in the February issue of
Agricultural Researchmagazine. Click
here to
read it on the web. Scientific contact: Bryan Bailey, ARS
Biocontrol of Plant
Diseases Laboratory, Beltsville, Md., phone (301) 504-6653/5682, fax (301)
504-5968, [email protected]. U.S. Department of Agriculture |