Leaves alternate between periods of gradually changing rates of photosynthesis and of dark metabolism under the natural daily cycle of light, yet provide a steady supply of sucrose which sustains uninterrupted development of growing parts of the plant. To do this, leaves must use stored carbohydrate during periods of low light and export and store carbon during periods of increased rates of photosynthesis. Regulation of leaf carbohydrate metabolism and export from leaves provides the means to meet these demands. This research project will study key processes by which leaves maintain this steady supply of sucrose for export. Regulation of carbon supply is particularly important for maintaining balanced functioning of plants in the face of rising atmospheric CO2 and altered balance between carbon supply and use that may result from genetic manipulation of plants.
