concept

C4 photosynthesis

Also known as: C4 photosynthetic pathway, C4 photosynthetic process

Facts (15)

Sources

The Ecology of Photosynthetic Pathways | Learn Science at Scitable nature.com Nature 12 facts

claimThe aquatic plant Hydrilla verticillata uses C4 photosynthesis to cope with reduced carbon dioxide concentrations that occur in warm, high-light aquatic environments during the summer.

referenceReiskind, J. B. et al. published 'Evidence that inducible C4-type photosynthesis is a chloroplastic CO2-concentrating mechanism in Hydrilla, a submersed monocot' in Plant Cell and Environment 20, 211–220 in 1997.

measurementC4 photosynthesis occurs in 3% of vascular plant species but accounts for 25% of terrestrial photosynthesis according to Sage (2004).

procedureThe C4 photosynthetic process involves transferring the 4-carbon acid to bundle sheath cells, where it is decarboxylated to release carbon dioxide next to rubisco.

claimC4 plants perform well in saline and dry habitats because C4 photosynthesis is saturated at lower CO2 concentrations and allows for lower stomatal conductance for a given photosynthetic rate.

claimThe C4 photosynthetic pathway differs from the C3 pathway in its initial carboxylating enzyme and initial products.

referenceVicentini, A. et al. published 'The age of the grasses and clusters of origins of C-4 photosynthesis' in Global Change Biology 14, 2963–2977 in 2008.

measurementC4 photosynthesis has evolved independently approximately fifty times, and about 50% of grass species are C4 photosynthesizers according to Edwards and Smith (2010).

referenceEhleringer, J. R. et al. published 'C-4 photosynthesis, atmospheric CO2 and climate' in Oecologia 112, 285–299 in 1997.

claimThe regeneration of phosphoenolpyruvate (PEP) in the C4 photosynthetic pathway requires more ATP than the C3 photosynthetic pathway.

referenceOsborne, C. P. & Freckleton, R. P. published 'Ecological selection pressures for C4 photosynthesis in the grasses' in Proceedings of the Royal Society B 276, 1753–1760 in 2009.

claimC4 photosynthesis is a relatively recent evolutionary innovation, with the earliest appearances occurring during the mid-Oligocene epoch approximately thirty million years ago when atmospheric CO2 levels were low.

An In-Depth Analysis of the Photosynthesis Process, Its Mechanisms ... publishing.emanresearch.org Ibrahim B. E. El Bashir, Loiy Elsir Ahmed Hassan, Sakina Yagi · Australian Herbal Insight 3 facts

referenceO. Ghannoum published 'C4 photosynthesis and water stress' in the Annals of Botany in 2009.

referenceA. S. Raghavendra and R. F. Sage published 'C4 photosynthesis and related CO2 concentrating mechanisms' in 2011.

referenceR. F. Sage published 'The evolution of C4 photosynthesis' in New Phytologist in 2004.