The effect of temperature on glutathione -^-transferase activity and glutathione in Alopecurus myosuroides Huds. (black-grass).

摘要

Herbicide resistant grass weeds are a growing problem throughout the UK. We have previously shown (Milner ei al., 2001) that natural climatic fluctuation causes changes in endogenous glutathione ^'-transferase (GST) enzyme activity in plants of Alopecurus myosuroides Huds. (black-grass) as they mature, which is believed to be linked to herbicide resistance in this species. This investigation has focused on the effect of growth at 10°C and 25°C on resistant and susceptible populations of A. myosuroides. Differences in GST activity were observed between resistant and susceptible populations, at both 10°C and 25°C, but these differences were transient at the lower temperature. The GSH pool size was higher at 10°C and similar in both populations. We speculate that these endogenous responses are part of a natural mechanism of acclimation to environmental change in this species. These observations imply that the control of resistant weeds by graminicides may be more effective when applied at lower temperatures and earlier growth stages. Hence, timing of graminicide application is critical.