Abstract
Portulacaria afra, a succulent plant, shifts from a predominantly C3 mode of gas exchange to a typical Crassulacean acid metabolism type CO2 uptake in response to water or NaCl stress. Control plants in the absence of water stress assimilated CO2 during the light (about 7-8 mg CO2 dm−2 hr−1), transpiration (about 1.5 g dm−2 hr−1) was predominantly during the day, stomates were open during the day, and there was little diurnal organic acid fluctuation. Stressed plants showed only dark CO2 uptake and dark water loss, nocturnal stomatal opening, and an increased diurnal fluctuation of titratable acidity. Within 2 weeks after rewatering, stressed plants returned to the control acid fluctuation levels indicating that the response to stress was reversible.
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Selected References
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- Bender M. M. C/C ratio changes in crassulacean Acid metabolism plants. Plant Physiol. 1973 Nov;52(5):427–430. doi: 10.1104/pp.52.5.427. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lerman J. C., Queiroz O. Carbon fixation and isotope discrimination by a crassulacean plant: dependence on the photoperiod. Science. 1974 Mar 22;183(4130):1207–1209. doi: 10.1126/science.183.4130.1207. [DOI] [PubMed] [Google Scholar]
- Scholander P. F., Bradstreet E. D., Hemmingsen E. A., Hammel H. T. Sap Pressure in Vascular Plants: Negative hydrostatic pressure can be measured in plants. Science. 1965 Apr 16;148(3668):339–346. doi: 10.1126/science.148.3668.339. [DOI] [PubMed] [Google Scholar]
- Szarek S. R., Ting I. P. Seasonal Patterns of Acid Metabolism and Gas Exchange in Opuntia basilaris. Plant Physiol. 1974 Jul;54(1):76–81. doi: 10.1104/pp.54.1.76. [DOI] [PMC free article] [PubMed] [Google Scholar]