The Extent of Starch Turnover in Mature Pepper Leaves in the Light

The extent of starch turnover in pepper leaves in the light has been estimated. After leaves were labelled with 14CO2 at constant specific activity for 4–7 h, the irradiance was reduced to a level which caused no net change in the starch content of the leaf, and the supply of 14CO2 was removed. There was no significant change in specific activity of starch over the following 6–10 h, thus there was no exchange of 14C-starch with 12C-assimilates entering the chloroplasts.