Increasing water use efficiency along the C3 to C4 evolutionary pathway: a stomatal optimization perspective
Journal Article
·
· Journal of Experimental Botany
- Western Univ., London, ON (Canada). Dept. of Biology; Duke Univ., Durham, NC (United States). Nicholas School of the Environment; DOE/OSTI
- Duke Univ., Durham, NC (United States). Nicholas School of the Environment; Duke Univ., Durham, NC (United States). Dept. of Civil and Environmental Engineering
- Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Crop Production Ecology; Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Ecology; Stockholm Univ. (Sweden). Dept. of Physical Geography and Quaternary Geology
- Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Crop Production Ecology
C4 photosynthesis evolved independently numerous times, probably in response to declining atmospheric CO2 concentrations, but also to high temperatures and aridity, which enhance water losses through transpiration. Here, the environmental factors controlling stomatal behaviour of leaf-level carbon and water exchange were examined across the evolutionary continuum from C3 to C4 photosynthesis at current (400 μmol mol–1) and low (280 μmol mol–1) atmospheric CO2 conditions. To this aim, a stomatal optimization model was further developed to describe the evolutionary continuum from C3 to C4 species within a unified framework. Data on C3, three categories of C3–C4 intermediates, and C4 Flaveria species were used to parameterize the stomatal model, including parameters for the marginal water use efficiency and the efficiency of the CO2-concentrating mechanism (or C4 pump); these two parameters are interpreted as traits reflecting the stomatal and photosynthetic adjustments during the C3 to C4 transformation. Neither the marginal water use efficiency nor the C4 pump strength changed significantly from C3 to early C3–C4 intermediate stages, but both traits significantly increased between early C3–C4 intermediates and the C4-like intermediates with an operational C4 cycle. At low CO2, net photosynthetic rates showed continuous increases from a C3 state, across the intermediates and towards C4 photosynthesis, but only C4-like intermediates and C4 species (with an operational C4 cycle) had higher water use efficiencies than C3 Flaveria. The results demonstrate that both the marginal water use efficiency and the C4 pump strength increase in C4 Flaveria to improve their photosynthesis and water use efficiency compared with C3 species. These findings emphasize that the advantage of the early intermediate stages is predominantly carbon based, not water related.
- Research Organization:
- Duke Univ., Durham, NC (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Biological and Environmental Research (BER). Earth and Environmental Systems Science Division
- Grant/Contract Number:
- SC0006967
- OSTI ID:
- 1625386
- Journal Information:
- Journal of Experimental Botany, Journal Name: Journal of Experimental Botany Journal Issue: 13 Vol. 65; ISSN 0022-0957
- Publisher:
- Oxford University PressCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Reducing stomatal density by expression of a synthetic epidermal patterning factor increases leaf intrinsic water use efficiency and reduces plant water use in a C4 crop
Physiological and growth responses of C3 and C4 plants at the Pleistocene glacial maximum
Journal Article
·
Wed Jul 17 20:00:00 EDT 2024
· Journal of Experimental Botany
·
OSTI ID:2477470
Physiological and growth responses of C3 and C4 plants at the Pleistocene glacial maximum
Journal Article
·
Thu Jun 01 00:00:00 EDT 1995
· Bulletin of the Ecological Society of America
·
OSTI ID:95890