Guillaume Tcherkez1, Paul Gauthier2, Thomas N Buckley3, Florian A Busch1, Margaret M Barbour4, Dan Bruhn5, Mary A Heskel6, Xiao Ying Gong7, Kristine Y Crous8, Kevin Griffin9, Danielle Way10, Matthew Turnbull11, Mark A Adams4, Owen K Atkin12, Graham D Farquhar1, Gabriel Cornic13. 1. Research School of Biology, College of Science, and ARC Center of Excellence for Translational Photosynthesis, Australian National University, Canberra, ACT, 2601, Australia. 2. Department of Geosciences, Princeton University, Princeton, NJ, 08540, USA. 3. IA Watson Grains Research Centre, University of Sydney, 12656 Newell Hwy, Narrabri, NSW, 2390, Australia. 4. Centre for Carbon, Water and Food, University of Sydney, 380 Werombi Rd, Brownlow Hill, NSW, 2570, Australia. 5. Section of Biology and Environmental Science, Department of Chemistry and Bioscience, Aalborg University, 9220, Aalborg East, Denmark. 6. The Ecosystems Center, Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA, 02543, USA. 7. Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, 85354, Freising, Germany. 8. Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia. 9. Department of Ecology, Evolution and Environmental Biology (E3B), Columbia University, 1200 Amsterdam Avenue, New York, NY, 10027, USA. 10. Department of Biology, University of Western Ontario, London, ON, N6A 5B7, Canada. 11. Centre for Integrative Ecology, School of Biological Sciences, University of Canterbury, PB 4800, Christchurch, New Zealand. 12. ARC Centre of Excellence in Plant Energy Biology, Division of Plant Science, Research School of Biology, Australian National University, Canberra, ACT, 2601, Australia. 13. Ecologie Systématique Evolution, Université Paris-Sud, 91405, Orsay Cedex, France.
Abstract
Contents 986 I. 987 II. 987 III. 988 IV. 991 V. 992 VI. 995 VII. 997 VIII. 998 References 998 SUMMARY: It has been 75 yr since leaf respiratory metabolism in the light (day respiration) was identified as a low-flux metabolic pathway that accompanies photosynthesis. In principle, it provides carbon backbones for nitrogen assimilation and evolves CO2 and thus impacts on plant carbon and nitrogen balances. However, for a long time, uncertainties have remained as to whether techniques used to measure day respiratory efflux were valid and whether day respiration responded to environmental gaseous conditions. In the past few years, significant advances have been made using carbon isotopes, 'omics' analyses and surveys of respiration rates in mesocosms or ecosystems. There is substantial evidence that day respiration should be viewed as a highly dynamic metabolic pathway that interacts with photosynthesis and photorespiration and responds to atmospheric CO2 mole fraction. The view of leaf day respiration as a constant and/or negligible parameter of net carbon exchange is now outdated and it should now be regarded as a central actor of plant carbon-use efficiency.
Contents 986 I. 987 II. 987 III. 988 IV. 991 V. 992 VI. 995 VII. 997 VIII. 998 References 998 SUMMARY: It has been 75 yr since leaf respiratory metabolism in the light (day respiration) was identified as a low-flux metabolic pathway that accompanies photosynthesis. In principle, it provides carbon backbones for nitrogen assimilation and evolves CO2 and thus impacts on plant carbon and nitrogen balances. However, for a long time, uncertainties have remained as to whether techniques used to measure day respiratory efflux were valid and whether day respiration responded to environmental gaseous conditions. In the past few years, significant advances have been made using carbon isotopes, 'omics' analyses and surveys of respiration rates in mesocosms or ecosystems. There is substantial evidence that day respiration should be viewed as a highly dynamic metabolic pathway that interacts with photosynthesis and photorespiration and responds to atmospheric CO2 mole fraction. The view of leaf day respiration as a constant and/or negligible parameter of net carbon exchange is now outdated and it should now be regarded as a central actor of plant carbon-use efficiency.