Abstract
Removal of the lower epidermis from a tobacco leaf allows a faster and wider range of water fluxes, without damaging the mesophyll. It also permits a more direct examination of the photosynthetic potential of the tissue at various levels of hydration.
The rehydration rate of leaf discs is essentially linear. It decreases with leaf age and is correlated with the rate of dehydration, but it is independent of the tissue's water potential, as estimated by the isopiestic method. The hydraulic permeability coefficient of water influx is directly related to water potential of the tissue, suggesting a mechanism for the regulaton of the hydration level of the leaf tissue.
The “energy of activation” of rehydration amounts to about 9 kilocalories per mole at intermediate dehydration, but it greatly declines following water loss in excess of 600 milligrams per gram fresh weight. The excessive dehydration is also characterized by a major increase in permeability (monitored by efflux of ions and materials absorbing ultraviolet light) and by a parallel decrease in photosynthetic activity. The interrelationship of these effects of excessive dehydration is discussed.
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Selected References
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- Boyer J. S., Bowen B. L. Inhibition of oxygen evolution in chloroplasts isolated from leaves with low water potentials. Plant Physiol. 1970 May;45(5):612–615. doi: 10.1104/pp.45.5.612. [DOI] [PMC free article] [PubMed] [Google Scholar]
- DAINTY J., GINZBURG B. Z. THE MEASUREMENT OF HYDRAULIC CONDUCTIVITY (OSMOTIC PERMEABILITY TO WATER) OF INTERNODAL CHARACEAN CELLS BY MEANS OF TRANSCELLULAR OSMOSIS. Biochim Biophys Acta. 1964 Jan 27;79:102–111. doi: 10.1016/0926-6577(64)90043-9. [DOI] [PubMed] [Google Scholar]
- Glinka Z., Reinhold L. Reversible Changes in the Hydraulic Permeability of Plant Cell Membranes. Plant Physiol. 1964 Nov;39(6):1043–1050. doi: 10.1104/pp.39.6.1043. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Henn F. A., Thompson T. E. Synthetic lipid bilayer membranes. Annu Rev Biochem. 1969;38:241–262. doi: 10.1146/annurev.bi.38.070169.001325. [DOI] [PubMed] [Google Scholar]
- KEDEM O., KATCHALSKY A. Thermodynamic analysis of the permeability of biological membranes to non-electrolytes. Biochim Biophys Acta. 1958 Feb;27(2):229–246. doi: 10.1016/0006-3002(58)90330-5. [DOI] [PubMed] [Google Scholar]
- Lopushinsky W. Effect of Water Movement on Ion Movement into the Xylem of Tomato Roots. Plant Physiol. 1964 May;39(3):494–501. doi: 10.1104/pp.39.3.494. [DOI] [PMC free article] [PubMed] [Google Scholar]
- MEES G. C., WEATHERLEY P. E. The mechanism of water absorption by roots. II. The role of hydrostatic pressure gradients across the cortex. Proc R Soc Lond B Biol Sci. 1957 Dec 3;147(928):381–391. doi: 10.1098/rspb.1957.0057. [DOI] [PubMed] [Google Scholar]
- Price H. D., Thompson T. E. Properties of liquid bilayer membranes separating two aqueous phases: temperature dependence of water permeability. J Mol Biol. 1969 May 14;41(3):443–457. doi: 10.1016/0022-2836(69)90287-3. [DOI] [PubMed] [Google Scholar]
- Reinhold L., Glinka Z. Reduction in Turgor Pressure as a Result of Extremely Brief Exposure to CO(2). Plant Physiol. 1966 Jan;41(1):39–44. doi: 10.1104/pp.41.1.39. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SAMPSON J. A method of replicating dry or moist surfaces for examination by light microscopy. Nature. 1961 Aug 26;191:932–933. doi: 10.1038/191932a0. [DOI] [PubMed] [Google Scholar]
- Shavit N., Degani H., San Pietro A. II. Effect of ionophorous antibiotics in chlorplasts. Biochim Biophys Acta. 1970 Aug 4;216(1):208–219. doi: 10.1016/0005-2728(70)90172-6. [DOI] [PubMed] [Google Scholar]
- Zelitch I. BIOCHEMICAL CONTROL OF STOMATAL OPENING IN LEAVES. Proc Natl Acad Sci U S A. 1961 Sep;47(9):1423–1433. doi: 10.1073/pnas.47.9.1423. [DOI] [PMC free article] [PubMed] [Google Scholar]