Abstract
Stomata of many plants have circadian rhythms in responsiveness to environmental cues as well as circadian rhythms in aperture. Stomatal responses to red light and blue light are mediated by photosynthetic photoreceptors; responses to blue light are additionally controlled by a specific blue-light photoreceptor. This paper describes circadian rhythmic aspects of stomatal responsiveness to red and blue light in Vicia faba. Plants were exposed to a repeated light:dark regime of 1.5:2.5 h for a total of 48 h, and because the plants could not entrain to this short light:dark cycle, circadian rhythms were able to "free run" as if in continuous light. The rhythm in the stomatal conductance established during the 1.5-h light periods was caused both by a rhythm in sensitivity to light and by a rhythm in the stomatal conductance established during the preceding 2.5-h dark periods. Both rhythms peaked during the middle of the subjective day. Although the stomatal response to blue light is greater than the response to red light at all times of day, there was no discernible difference in period, phase, or amplitude of the rhythm in sensitivity to the two light qualities. We observed no circadian rhythmicity in net carbon assimilation with the 1.5:2.5 h light regime for either red or blue light. In continuous white light, small rhythmic changes in photosynthetic assimilation were observed, but at relatively high light levels, and these appeared to be attributable largely to changes in internal CO2 availability governed by stomatal conductance.
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Selected References
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- Fredeen A. L., Hennessey T. L., Field C. B. Biochemical Correlates of the Circadian Rhythm in Photosynthesis in Phaseolus vulgaris. Plant Physiol. 1991 Sep;97(1):415–419. doi: 10.1104/pp.97.1.415. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gorton H. L., Williams W. E., Binns M. E., Gemmell C. N., Leheny E. A., Shepherd A. C. Circadian Stomatal Rhythms in Epidermal Peels from Vicia faba. Plant Physiol. 1989 Aug;90(4):1329–1334. doi: 10.1104/pp.90.4.1329. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hennessey T. L., Field C. B. Circadian Rhythms in Photosynthesis : Oscillations in Carbon Assimilation and Stomatal Conductance under Constant Conditions. Plant Physiol. 1991 Jul;96(3):831–836. doi: 10.1104/pp.96.3.831. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Iino M., Ogawa T., Zeiger E. Kinetic properties of the blue-light response of stomata. Proc Natl Acad Sci U S A. 1985 Dec;82(23):8019–8023. doi: 10.1073/pnas.82.23.8019. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kana T. M., Miller J. H. Effect of Photoperiod on Stomatal Opening in Vicia faba. Plant Physiol. 1977 Nov;60(5):803–804. doi: 10.1104/pp.60.5.803. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Scarth G. W., Shaw M. STOMATAL MOVEMENT AND PHOTOSYNTHESIS IN PELARGONIUM. I. EFFECTS OF LIGHT AND CARBON DIOXIDE. Plant Physiol. 1951 Apr;26(2):207–225. doi: 10.1104/pp.26.2.207. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zeiger E., Field C. Photocontrol of the Functional Coupling between Photosynthesis and Stomatal Conductance in the Intact Leaf : Blue Light and Par-Dependent Photosystems in Guard Cells. Plant Physiol. 1982 Aug;70(2):370–375. doi: 10.1104/pp.70.2.370. [DOI] [PMC free article] [PubMed] [Google Scholar]