Ecological Significance of the Interaction of Photosynthesis Light and Dark Processes

Abstract

The kinetics of 14C incorporation into \nglycolate was studied after changing the export of photosynthetic products from \nthe leaf. It has been shown that the ribulose-bisphosphate-oxygenase \npathway of glycolate formation works in the stationary state of the plant. \nAn excess of photosyntates or a decrease in the amount of light primary \nproducts, as well as nitrates in the leaves, immediately turns on the \ntransketolase pathway of glycolate formation. In this case, part of the oxygen formed in the photochemical reactions \nof chloroplasts ceases to be released from the leaf. After oxygen \nreceives an electron from ferredoxin in the electron transport chain of \nchloroplasts, it starts (through photorespiration) the formation of \nnon-carbohydrate photosyntates and metabolic processes in the cytoplasm. It was \nconcluded that the main function of photorespiration \nin the regulation of photosynthesis is maintaining a balance between \nlight and dark processes of photosynthesis on change of living conditions.