Light-induced Increase in Sucrose Phosphate Synthetase Activity in Leaves of Lolium temulentum

Abstract
Mature leaves of Lolium temulentum L. were assayed for sucrose phosphate synthetase activity at different times during the photoperiod. There was a rapid increase in activity at the onset of illumination which was not observed in leaves maintained in darkness. The activity prior to illumination was insufficient to catalyse the rates of sucrose synthesis observed in illuminated detached leaves; after 15 min illumination the two processes were of similar magnitude.