The influence of sucrose on sucrose phosphate synthase (SPS) activity and on photosynthesis was studied in sunflower (Var. Morden) by starving one month old plants in dark for 48 hours followed by exposure to light for one hour. The level of sucrose thus accumulated in light exposed plants failed to influence either the SPS activity or photosynthesis. Further, SPS activity was also unaffected by light.
