Abstract
Rate of net CO2 assimilation by soil-grown soybean plants were studied over a range of relative leaf water contents at each of four levels of irradiance. There was a large interaction between light level and leaf water deficit on the rate of CO2 assimilation. The effect of leaf water deficit on assimilation became larger as irradiance increased. Both stomatal resistance to CO2 transport and mesophyll resistance to CO2 assimilation increased as leaf-water deficit increased. The increase in both resistance with changing leaf-water content was largest at high irradiance and became smaller as irradiance decreased. Relief of soil-moisture stress by watering induced large oscillations of CO2 assimilation, stomatal resistance, and mesophyll resistance. The oscillation of the mesophyll resistance occurred in the absence of changes in relative water content and appeared to be related to oscillations in leaf temperature. The observed increase in mesophyll resistance with decreasing leaf-water content under nonoscillative conditions may be caused by changes in leaf temperature rather than leaf water content.
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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]
- Kanemasu E. T., Tanner C. B. Stomatal diffusion resistance of snap beans. I. Influence of leaf-water potential. Plant Physiol. 1969 Nov;44(11):1547–1552. doi: 10.1104/pp.44.11.1547. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kuiper P. J. Temperature Dependence of Photosynthesis of Bean Plants as Affected by Decenylsuccinic Acid. Plant Physiol. 1965 Sep;40(5):915–918. doi: 10.1104/pp.40.5.915. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mederski H. J., Chen L. H., Curry R. B. Effect of leaf water deficit on stomatal and nonstomatal regulation of net carbon dioxide assimilation. Plant Physiol. 1975 Apr;55(4):589–593. doi: 10.1104/pp.55.4.589. [DOI] [PMC free article] [PubMed] [Google Scholar]