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Carbon isotope discrimination in photosynthesis of CAM plants

Journal Article


Abstract


  • SUCCULENT plants capable of Crassulacean acid metabolism (CAM) show extremely variable carbon isotope discrimination ratios1,2. This ratio, usually expressed as a δ13C value referred to a standard3, has emerged as a useful diagnostic criterion to determine photosynthetic pathways in higher plants3-5. Species with the C 4 photosynthetic pathway6 show less negative δ13C values than do species with the C3 photosynthetic pathway. The difference in isotope discrimination is believed to be a result of the different fractionation characteristics of the primary phosphoenolpyruvate (PEP) carboxylase of C4 plants and primary ribulosediphosphate (RuDP) carboxylase of C3 plants7. Within a species, the δ13C value for total carbon does not usually vary by more than ±0.5‰ and it is largely insensitive to environmental conditions during growth8, although the soluble components within a particular leaf may show some variation9. Examples of the constancy of δ13C values are shown in the genus Atriplex, where C4 species have less negative values (for total carbon) of -8 to -12‰ than C3 species which range between -25 and -27‰ (ref. 8). © 1973 Nature Publishing Group.

UOW Authors


  •   Osmond, Barry B.

Publication Date


  • 1973

Published In


Citation


  • Osmond, C. B., Allaway, W. G., Sutton, B. G., Troughton, J. H., Queiroz, O., Lüttge, U., & Winter, K. (1973). Carbon isotope discrimination in photosynthesis of CAM plants. Nature, 246(5427), 41-42. doi:10.1038/246041a0

Scopus Eid


  • 2-s2.0-0002525868

Web Of Science Accession Number


Start Page


  • 41

End Page


  • 42

Volume


  • 246

Issue


  • 5427

Abstract


  • SUCCULENT plants capable of Crassulacean acid metabolism (CAM) show extremely variable carbon isotope discrimination ratios1,2. This ratio, usually expressed as a δ13C value referred to a standard3, has emerged as a useful diagnostic criterion to determine photosynthetic pathways in higher plants3-5. Species with the C 4 photosynthetic pathway6 show less negative δ13C values than do species with the C3 photosynthetic pathway. The difference in isotope discrimination is believed to be a result of the different fractionation characteristics of the primary phosphoenolpyruvate (PEP) carboxylase of C4 plants and primary ribulosediphosphate (RuDP) carboxylase of C3 plants7. Within a species, the δ13C value for total carbon does not usually vary by more than ±0.5‰ and it is largely insensitive to environmental conditions during growth8, although the soluble components within a particular leaf may show some variation9. Examples of the constancy of δ13C values are shown in the genus Atriplex, where C4 species have less negative values (for total carbon) of -8 to -12‰ than C3 species which range between -25 and -27‰ (ref. 8). © 1973 Nature Publishing Group.

UOW Authors


  •   Osmond, Barry B.

Publication Date


  • 1973

Published In


Citation


  • Osmond, C. B., Allaway, W. G., Sutton, B. G., Troughton, J. H., Queiroz, O., Lüttge, U., & Winter, K. (1973). Carbon isotope discrimination in photosynthesis of CAM plants. Nature, 246(5427), 41-42. doi:10.1038/246041a0

Scopus Eid


  • 2-s2.0-0002525868

Web Of Science Accession Number


Start Page


  • 41

End Page


  • 42

Volume


  • 246

Issue


  • 5427