Control of circadian rhythm in nitrate reductase activity in Wolffia microscopica Griff

Abstract

In Wolffia microscopica, the activity of nitrate reductase showed strong diurnal rhythmicity with a peak in the forenoon. The rhythmicity persists under extended dark conditions as well as under continuous light. The phase of the rhythm shifts under inverted light-dark cycles. Studies with various inhibitors of macromolecular synthesis suggest that the increase in enzyme activity depends on the new synthesis of both RNA and protein.