Effects of abscisic acid on photosynthesis in whole leaves: changes in CO2 assimilation, levels of carbon-reduction-cycle intermediates, and activity of ribulose-1,5-bisphosphate carboxylase
- 1 December 1986
- journal article
- research article
- Published by Springer Nature in Planta
- Vol. 169 (4), 536-545
- https://doi.org/10.1007/bf00392104
Abstract
Addition of abscisic acid (ABA) to the transpiration stream of leaves of Xanthium strumarium caused stomatal closure and, simultaneously, an independent reduction of CO2 assimilation. An attempt was made to identify the site of inhibition that had occurred, presumably, in the path of photosynthetic carbon reduction. Leaves were supplied with ABA. When inhibition of photosynthesis was fully expressed, the partial pressure of CO2 in the intercellular spaces was adjusted to the level that had occurred before ABA had been applied and before stomata had closed. Then the leaf was rapidly frozen, and pool sizes of carbon-reduction-cycle intermediates were determined. Comparison with samples from control leaves showed that the decline in the rate of assimilation was associated with decreases of the levels of 3-phosphoglycerate, triose phosphates, fructose-1,6-bisphosphate, and hexose phosphates. In contrast, the pool size ofribulose-1,5-bisphosphate (RuBP) remained unchanged or even increased. Similar results were obtained with leaves of Zea mays, in which the levels of all measured intermediates, including malate and pyruvate, declined after application of ABA; the level of RuBP rose. In other experiments with leaves of X. strumarium, rates of CO2 assimilation were lowered by reductions in the partial pressure of CO2 in the ambient air. Relationships between assimilation rates of CO2 and metabolite levels were similar to those determined after applications of ABA at constant partial pressure of CO2. Because the uptake of CO2 decreased in ABA-treated leaves in spite of continued availability of CO2 and RuBP, we concluded that application of ABA caused an inhibition of the carboxylation of RuBP in both, the C3 species, X. strumarium, and the C4 species, Z. mays. However, the RuBP-carboxylase activity of rapidly prepared extracts of ABA-treated leaves was as high as that of control leaves. The substance or the process which, after application of ABA, interferes with the carboxylation of RuBP remains unknown.This publication has 27 references indexed in Scilit:
- Binding of a Phosphorylated Inhibitor to Ribulose Bisphosphate Carboxylase/Oxygenase during the NightPlant Physiology, 1985
- Activation State of Ribulose Bisphosphate Carboxylase in Soybean LeavesPlant Physiology, 1984
- Nonstomatal Inhibition of Net CO2 Uptake by (±) Abscisic Acid in Pharbitis nilPlant Physiology, 1983
- Measurement and Preservation of the in Vivo Activation of Ribulose 1,5-Bisphosphate Carboxylase in Leaf ExtractsPlant Physiology, 1982
- Abscisic Acid and Photosynthesis in Isolated Leaf Mesophyll CellPlant Physiology, 1981
- Regulation of Ribulose Bisphosphate Carboxylase Activity in Intact Wheat Leaves by Light, CO2, and TemperatureJournal of Experimental Botany, 1980
- Changes in the Levels of Abscisic Acid and Its Metabolites in Excised Leaf Blades of Xanthium strumarium during and after Water StressPlant Physiology, 1980
- A biochemical model of photosynthetic CO2 assimilation in leaves of C3 speciesPlanta, 1980
- Effects of Phaseic Acid and Dihydrophaseic Acid on Stomata and the Photosynthetic ApparatusPlant Physiology, 1980
- Spectrophotometric characteristics of chlorophylls a and b and their phenophytins in ethanolBiochimica et Biophysica Acta (BBA) - Biophysics including Photosynthesis, 1965