Abstract
Air pollutants are known to cause visible leaf injury as well as impairment of photosynthetic CO2 fixation. Here we evaluate whether the effects on photosynthesis are large enough to cause changes in the relative composition of stable carbon isotopes, δ13C, of plant tissue samples, and, if so, how the changes relate to visual leaf injury. For that purpose, several woody and herbaceous plant species were exposed to SO2 + O3 and SO2 + O3 + NO2 for one month (8 hours per day, 5 days per week). At the end of the fumigations, the plants were evaluated for visual leaf lesions, and δ13C of leaf tissue was determined. Woody plants generally showed less visual leaf injury and smaller effects on δ13C of pollutant exposure than did herbaceous plants. If δ13C was affected by pollutants, it became, with few exceptions, less negative. The data from the fumigation experiments were consistent with δ13C analyses of whole wood of annual growth rings from two conifer tree species, Pseudotsuga menziesii and Pinus strobus. These trees had been exposed until 1977 to exhaust gases from a gas plant at Lacq, France. Wood of both conifer species formed in the polluted air of 1972 to 1976 had less negative δ13C values than had wood formed in the much cleaner air in 1982 to 1986. No similar, time-dependent differences in δ13C of wood were observed in trees which had been continuously growing in clean air. Our δ13C data from both relatively short-term artificial exposures and long-term natural exposure are consistent with greater stomatal limitation of photosynthesis in polluted air than in clean air.
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- Bradford K. J., Sharkey T. D., Farquhar G. D. Gas Exchange, Stomatal Behavior, and deltaC Values of the flacca Tomato Mutant in Relation to Abscisic Acid. Plant Physiol. 1983 May;72(1):245–250. doi: 10.1104/pp.72.1.245. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Olszyk D. M., Tingey D. T. Joint Action of O(3) and SO(2) in Modifying Plant Gas Exchange. Plant Physiol. 1986 Oct;82(2):401–405. doi: 10.1104/pp.82.2.401. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Park R., Epstein S. Metabolic fractionation of C & C in plants. Plant Physiol. 1961 Mar;36(2):133–138. doi: 10.1104/pp.36.2.133. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sternberg L. O., Deniro M. J., Johnson H. B. Isotope ratios of cellulose from plants having different photosynthetic pathways. Plant Physiol. 1984 Mar;74(3):557–561. doi: 10.1104/pp.74.3.557. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sternberg L., Deniro M. J. Isotopic Composition of Cellulose from C3, C4, and CAM Plants Growing Near One Another. Science. 1983 May 27;220(4600):947–949. doi: 10.1126/science.220.4600.947. [DOI] [PubMed] [Google Scholar]
- Stuiver M. Atmospheric carbon dioxide and carbon reservoir changes. Science. 1978 Jan 20;199(4326):253–258. doi: 10.1126/science.199.4326.253. [DOI] [PubMed] [Google Scholar]
- Wong W. W., Benedict C. R., Kohel R. J. Enzymic Fractionation of the Stable Carbon Isotopes of Carbon Dioxide by Ribulose-1,5-bisphosphate Carboxylase. Plant Physiol. 1979 May;63(5):852–856. doi: 10.1104/pp.63.5.852. [DOI] [PMC free article] [PubMed] [Google Scholar]