Effect of Water Deficit on Photosynthesis and Tuber Metabolism in Potatoes

Abstract

The primary effect of a period of drought on potato plants was to reduce the rate of photosynthesis. Decreases in CO₂ uptake could mainly be ascribed to an increase in the residual resistance to CO₂ transport. Levels of sugars and of starch-synthesizing enzymes in extracts from tubers of droughted and control plants were similar, and it is likely therefore that the effect of drought on tuber growth is exerted mainly via a reduction in the supply of assimilate.