Rapid tests for herbicide resistance in black-grass based on elevated glutathione S-transferase activity and abundance

Black-grass (Alopecurus myosuroides) is a major problem weed in winter cere al crops in the UK. Control is hindered by the presence of black-grass biot ypes resistant to herbicides. Early detection of these biotypes would allow alternative crop protection measures to be employed. Data are presented de monstrating raised glutathione S-transferase (GST) activities in black-gras s plants that have survived various herbicide treatments in field trials. I n addition, the detection of raised GST protein abundance in these plants u sing enzyme-linked immunosorbent assay (ELISA) technology is described. The ELISA utilises antisera raised against a GST subunit from the resistant bl ack-grass biotype Peldon, purified in this laboratory. Changes in GST activ ity from February to May 1999 are also presented. Detection of GST activity (by colorimetry) and GST abundance (by ELISA) is discussed in relation to the development of a quick field-test for herbicide-resistant biotypes that will give accurate results before application of post-emergent herbicides.