Abstract
Cuticular properties affect the gas exchange of leaves, but little is known about how much CO2 and water vapor cross the cuticular barrier or whether low water potentials affect the process. Therefore, we measured the cuticular conductances for CO2 and water vapor in grape (Vitis vinifera L.) leaves having various water potentials. The lower leaf surface was sealed to force all gas exchange through the upper surface, which was stoma-free. In this condition both gases passed through the cuticle, and the CO2 conductance could be directly determined from the internal mole fraction of CO2 near the compensation point, the external mole fraction of CO2, and the CO2 flux. The cuticle allowed small amounts of CO2 and water vapor to pass through, indicating that gas exchange occurs in grape leaves no matter how tightly the stomata are closed. However, the CO2 conductance was only 5.7% of that for water vapor. This discrimination against CO2 markedly affected calculations of the mole fraction of CO2 in leaves as stomatal apertures decreased. When the leaf dehydrated, the cuticular conductance to water vapor decreased, and transpiration and assimilation diminished. This dehydration effect was largest when turgor decreased, which suggests that cuticular gas exchange may have been influenced by epidermal stretching.
Full Text
The Full Text of this article is available as a PDF (722.3 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Dugger W. M. THE PERMEABILITY OF NON-STOMATE LEAF EPIDERMIS TO CARBON DIOXIDE. Plant Physiol. 1952 Jul;27(3):489–499. doi: 10.1104/pp.27.3.489. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jenks M. A., Joly R. J., Peters P. J., Rich P. J., Axtell J. D., Ashworth E. N. Chemically Induced Cuticle Mutation Affecting Epidermal Conductance to Water Vapor and Disease Susceptibility in Sorghum bicolor (L.) Moench. Plant Physiol. 1994 Aug;105(4):1239–1245. doi: 10.1104/pp.105.4.1239. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lauer M. J., Boyer J. S. Internal CO(2) Measured Directly in Leaves : Abscisic Acid and Low Leaf Water Potential Cause Opposing Effects. Plant Physiol. 1992 Apr;98(4):1310–1316. doi: 10.1104/pp.98.4.1310. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Moreshet S. Effect of environmental factors on cuticular transpiration resistance. Plant Physiol. 1970 Dec;46(6):815–818. doi: 10.1104/pp.46.6.815. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mott K. A., O'leary J. W. Stomatal Behavior and CO(2) Exchange Characteristics in Amphistomatous Leaves. Plant Physiol. 1984 Jan;74(1):47–51. doi: 10.1104/pp.74.1.47. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Parkhurst D. F., Wong S. C., Farquhar G. D., Cowan I. R. Gradients of Intercellular CO(2) Levels Across the Leaf Mesophyll. Plant Physiol. 1988 Apr;86(4):1032–1037. doi: 10.1104/pp.86.4.1032. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sharkey T. D., Imai K., Farquhar G. D., Cowan I. R. A Direct Confirmation of the Standard Method of Estimating Intercellular Partial Pressure of CO(2). Plant Physiol. 1982 Mar;69(3):657–659. doi: 10.1104/pp.69.3.657. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sorsby A., Reading H. W., Bunyan J. Effect of vitamin A deficiency on the retina of the experimental rabbit. Nature. 1966 Jun 4;210(5040):1011–1015. doi: 10.1038/2101011a0. [DOI] [PubMed] [Google Scholar]
- Woolley J. T. Relative permeabilities of plastic films to water and carbon dioxide. Plant Physiol. 1967 May;42(5):641–643. doi: 10.1104/pp.42.5.641. [DOI] [PMC free article] [PubMed] [Google Scholar]