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Biochemical components of the photosynthetic CO2 compensation point of higher plants

1975; Elsevier BV; Volume: 66; Issue: 4 Linguagem: Inglês

10.1016/0006-291x(75)90520-3

1090-2104

Daniel P. Kestler, Berger C. Mayne, T. B. Ray, Lisa Goldstein, R. H. Brown, C. C. Black,

Soil Carbon and Nitrogen Dynamics

Barley, Panicum milioides and Panicum maximum were exposed to 14CO2 near their photosynthetic CO2 compensation points and their respective 14C-products were determined. In short exposure times Panicum maximum had 100% of its 14C in malate and aspartate whereas Panicum milioides and barley had 16 and 3% of their respective 14C in C4 organic acids. Near the respective CO2 compensation points a linear relationship occurs in plotting the ratio of glycine, serine, and glycerate to C4 organic acids. The ratio of ribulose 1,5-bisphosphate oxygenase to phosphoenolpyruvate carboxylase is linear with their CO2 compensation points. The photosynthetic CO2 compensation point apparently is controlled by the activity of enzymes producing photorespiration metabolites and the activity of phospheonolpyruvate carboxylase.