光呼吸对光合过程中磷代谢的影响

EFFECTS OF PHOTORESPIRATION ON PHOSPHATE METABOLISM DURING PHOTOSYNTHESIS

摘要:

与光呼吸受抑制的 2％O_2浓度下相比,在 21％O_2浓度下.离体甘薯叶细胞光合作用最适介质无机磷浓度较低.另外,在21％O_2浓度下,降低甘薯叶细胞介质 NaHCO_3浓度,叶细胞光下吸收介质~(32)Pi的量减少;降低完整菠菜叶绿体介质 NaHCO_3浓度,乙醇酸形成相对加强,而介质~(32)Pi掺入到有机磷化合物的量则相对减少.这些结果表明,有利于光呼吸的条件,可降低光合对外界Pi的需求量.

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 ...