Abstract:Isolated sweet potato (Ipomoea batatas Lam.) leaf cells and spinach (Spinacia oleracea L.) intact chloroplasts were used to study the effects of photorespiration on phosphate metabolism during photosynthesis. The results were as follows: 1. Sweet potato leaf cells had a lower optimum Pi concentration for photosynthesis in the reaction medium with 21% O2 concentration than that with 2%O2 in which photorespiration was inhibited(Fig.l). 2. With 21% O2 concentration, the uptake of 32Pi by sweet potato leaf ...