| Euphorbia esula, which is commonly known as leafy spurge, is a noxious weed. The roots of leafy spurge are adapted to survive in the subfreezing temperatures of winter and produce new shoots and roots very early the following spring. The aim of this study was to investigate the role of various factors on alpha-amylase activity, which provides simple sugars responsible for spring regrowth. Levels of alpha-amylase activity in cultured roots of leafy spurge were examined for possible response to cold temperatures, sucrose starvation, exogenously supplied GA3, and the quality of light. alpha-Amylase activity was enhanced by cold temperature in field grown roots. However, in cultured roots, alpha-amylase activity was found in all samples. alpha-Amylase activity increased under sucrose starvation, but this increase in the activity was due to osmotic stress. There was a consistent increase in alpha-amylase activity with increases in exogenously applied GA3. Maximum activity was produced by application of 0.3 muM GA3 at 25°C. In addition to this, the exposure of cultured roots to red light (R) also increased alpha-amylase activity. |
