Studies on the induction of chlorophyll fluorescence in barley protoplasts. III. Correlation betweeen changes in the level of glycerate 3-phosphate and the pattern of fluorescence quenching

Abstract

Metabolite levels were measured in dark-adapted, isolated barley protoplasts exposed to illumination. The level of glycerate 3-phosphate showed a large peak 2 min after the onset of illumination in protoplast preparations which displayed an oscillatory transient in the rate of O 2 evolution and in the yield of chlorophyll fluorescence (Quick, W.P. and Horton, P. (1984) Proc. R. Soc. Lond. B. 220, 361–370). In protoplasts which did not show this oscillatory behaviour the level of glycerate-3-P steadily rose to its steady-state value. The relationships between electron transfer and carbon assimilation that underlie these transients in O 2 evolution, chlorophyll fluorescence and glycerate-3-phosphate level are discussed.