Amylase synthesis and stability in crested wheatgrass seeds at low water potentials.

Drying of seeds of Agropyron desertorum (Fisch. ex Link) Schult. did not result in breakdown of alpha-amylase nor impair the ability of seeds to resume its synthesis when moistened again. beta-Amylase activity did not change during 5 days of germination at a water potential of 0 atmosphere nor during 40 days of incubation at -40 atmospheres. Seeds synthesized alpha-amylase at 0, -20, and -40 atmospheres, but not at -60 atmospheres. At 0 and -20 atmospheres, the log of alpha-amylase activity was linearly related to hastening of germination. But at -40 atmospheres, seeds synthesized alpha-amylase during a time when there was little hastening of germination. Thus, it appears that other biochemical reactions are less drought-tolerant than synthesis of alpha-amylase. It is concluded that inhibition of alpha-amylase synthesis is not a controlling factor in the germination of these seeds at low water potentials.