title: The relationship between steady-state gas exchange of bean leaves and the levels of carbon-reduction-cycle intermediates.
abstract: The relationship between the gas-exchange characteristics of attached leaves of Phaseolus vulgaris L. and the pool sizes of several carbon-reduction-cycle intermediates was examined. After determining the rate of CO2 assimilation at known intercellular CO2 pressure, O2 pressure and light, the leaf was rapidly killed (<0.1 s) and the levels of ribulose-1,5-bisphosphate (RuBP), 3-phosphoglyceric acid (PGA), fructose-1,6-bisphosphate, fructose-6-phosphate, glucose-6-phosphate, glyceraldehyde-3-phosphate, and dihydroxyacetone phosphate were measured. In 210 mbar O2, photosynthesis appeared RuBP-saturated at low CO2 pressure and RuBP-limited at high CO2 pressure. In 21 mbar (2%) O2, the level of RuBP always appeared saturating. Very high levels of PGA and other phosphate-containing compounds were found with some conditions, especially under low oxygen.
authors.affiliation: Department of Environmental Biology, Research School of Biological Sciences, Australian National University, P.O. Box 475, 2601, Canberra City, A.C.T., Australia.
authors.forename: M R
authors.initials: MR
authors.lastname: Badger
authors.forename: T D
authors.initials: TD
authors.lastname: Sharkey
authors.forename: S
authors.initials: S
authors.lastname: von Caemmerer