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Models of carbon metabolism in C 3 ‐C 4 intermediate plants as applied to the evolution of C 4 photosynthesis
Author(s) -
PEISKER M.
Publication year - 1986
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/j.1365-3040.1986.tb01620.x
Subject(s) - photosynthesis , phosphoenolpyruvate carboxylase , pyruvate carboxylase , c4 photosynthesis , isotopes of carbon , ribulose , kinetic isotope effect , enzyme , isotope , chemistry , biology , botany , rubisco , biochemistry , deuterium , physics , quantum mechanics
Models developed to explain the biphasic response of CO 2 compensation concentration to O 2 concentration and the C 3 ‐like carbon isotope discrimination in C 3 ‐C 4 intermediate species are used to characterize quantitatively the steps necessary in the evolution of C 4 photosynthesis. The evolutionary stages are indicated by model outputs, CO 2 compensation concentration and δ 13 C value. The transition from intermediate plants to C 4 plants requires the complete formation of C 4 cycle capacity, expressed by the models as transition from C 4 cycle limitation by phosphoenolpyruvate (PEP) regeneration rate to limitation by PEP carboxylase activity. Other steps refer to CO 2 leakage from bundle sheath cells, to further augmentations of C 4 cycle components, to the repression of ribulose‐1,5‐bisphos‐phate carboxylase in the mesophyll cells, and to a decrease in the CO 2 affinity of the enzyme. Possibilities of extending the suggested approach to other physiological characteristics, and the adaptive significance of the steps envisaged, are discussed.