Induction of amylase in mustard seedlings by phytochrome.

In the cotyledons of mustard seedlings (Sinapis alba L.) amylase activity can be induced by phytochrome. In the dark amylase activity remains low. Gibberellic acid (GA3) does not stimulate an increase of amylase activity in this system. Inhibitors of RNA and protein synthesis strongly inhibit the increase of amylase activity mediated by phytochrome. In gel electrophoresis amylase from mustard seedlings reveals 3 bands. The electrophoretic pattern is the same for extracts from dark-grown and from irradiated seedlings. When mustard amylases were incubated with starch the pattern of products was similar to that produced by commercially available barley β-amylase and not similar to that produced by Bacillus subtilis α-amylase.