Summary
Diurnal measurements of chlorophyll a fluorescence from cacti (Nopalea cochenillifera, Opuntia ficus-indica, and Opuntia wentiana) growing in northern Venezuela were used to determine photochemical fluorescence quenching related to the reduction state of the primary electron acceptor of PS II as well as non-photochemical fluorescence quenching which reflects the fraction of energy going primarily into radiationless deexcitation. The cladodes used in this study were oriented such that one surface received direct sunlight in the morning and the other one during the afternoon. Both surfaces exhibited large increases in radiationless energy dissipation from the photochemical system accompanied by decreases in PS II photochemical efficiency during direct exposure to natural sunlight. During exposure to sunlight in the morning, dissipation of absorbed light energy through photosynthesis and radiationless energy dissipation was sufficient to maintain Q, the primary electron acceptor for PS II, in a low reduction state. During exposure to sunlight in the afternoon, however, the reduction state of Q rose to levels greater than 50%, presumably due to a decrease in photosynthetic electron transport as the decarboxylation of the nocturnally accumulated malic acid was completed. Exposure to direct sunlight in the afternoon also led to more sustained increases in radiationless energy dissipation. Furthermore, the increases in radiationless energy dissipation during exposure of a water-stressed cladode of O. wentiana to direct sunlight were much greater than those from other well-watered cacti, presumably due to sustained stomatal closure and decreased rates of photosynthetic electron transport. These results indicate that the radiationless dissipation of absorbed light is an important process in these CAM plants under natural conditions, and may reflect a protective mechanism against the potentially damaging effects of the accumulation of excessive energy, particularly under conditions where CO2 availability is restricted.
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Abbreviations
- CAM :
-
crassulacean acid metabolism
- F o :
-
instantaneous fluorescence emission
- F M :
-
maximum fluorescence emission
- F v :
-
variable fluorescence emission
- K D :
-
rate constant for radiationless energy dissipation in the antenna chlorophyll
- PFD :
-
photon flux density
- PS I :
-
photosystem I
- PS II :
-
photosystem II
- Q :
-
primary electron acceptor of photosystem II
- q NP :
-
non-photochemical fluorescence quenching
- q P :
-
photochemical fluorescence quenching
- T C :
-
cladode temperature
References
Adams WW III (1988) Photosynthetic acclimation and photoinhibition of terrestrial and epiphytic CAM tissues growing in full sunlight and deep shade. Aust J Plant Physiol 15:123–134
Adams WW III, Smith SD, Osmond CB (1987) Photoinhibition of the CAM succulent Opuntia basilaris growing in Death Valley: evidence from 77K fluorescence and quantum yield. Oecologia (Berlin) 71:221–228
Adams WW III, Terashima I, Brugnoli E, Demmig B (1988) Comparisons of photosynthesis and photoinhibition in the CAM vine Hoya australis and several C3 vines growing on the coast of eastern Australia. Plant Cell Environ 11:173–181
Björkman O (1987) Low-temperature chlorophyll fluorescence in leaves and its relationship to photon yield of photosynthesis in photoinhibition. In: Kyle DJ, Osmond CB, Arntzen CJ (eds) Photoinhibition. Elsevier, Amsterdam, pp 123–144
Björkman O, Demmig B (1987) Photon yield of O2 evolution and chlorophyll fluorescence characteristics at 77K among vascular plants of diverse origins. Planta 170:489–504
Demmig B, Björkman O (1987) Comparison of the effect of excessive light on chlorophyll fluorescence (77K) and photon yield of O2 evolution in leaves of higher plants. Planta 171:171–184
Demmig B, Winter K (1988a) Light response of CO2 assimilation, reduction state of Q, and radiationless energy dissipation in intact leaves. Aust J Plant Physiol 15:151–162
Demmig B, Winter K (1988b) Characterisation of three components of non-photochemical fluorescence quenching and their response to photoinhibition. Aust J Plant Physiol 15:163–177
Demmig B, Winter K, Krüger A, Czygan F-C (1987) Photoinhibition and zeaxanthin formation in intact leaves. A possible role of the xanthophyll cycle in the dissipation of excess light energy. Plant Physiol 84:218–224
Demmig B, Winter K, Krüger A, Czygan F-C (1988) Zeaxanthin and the heat dissipation of excess light energy in Nerium oleander exposed to a combination of high light and water stress. Plant Physiol 87:17–24
Demmig-Adams B, Adams WW III, Winter K, Meyer A, Schreiber U, Pereira JS, Krüger A, Czygan F-C, Lange OL (1989a) Photochemical efficiency of PS II, photon yield of O2 evolution, photosynthetic capacity, and carotenoid composition during the “midday depression” of net CO2 uptake in Arbutus unedo growing in Portugal. Planta 177:377–387
Demmig-Adams B, Winter K, Krüger A, Czygan F-C (1989b) Light response of CO2 assimilation, dissipation of excess excitation energy, and zeaxanthin content of sun and shade leaves. Plant Physiol 90
Díaz M, Medina E (1984) Actividad CAM de cactaceas en condiciones naturales. In: Medina E (ed) Eco-Fisiologia de Plantas CAM. Centro Internacional de Ecología Tropical, Caracas, pp 98–113
Kitajima M, Butler WL (1975) Quenching of chlorophyll fluorescence and primary photochemistry in chloroplasts by dibromothymoquinone. Biochim Biophys Acta 376:105–115
Lange OL, Medina E (1979) Stomata of the CAM plant Tillandsia recurvata respond directly to humidity. Oecologia (Berlin) 40:357–363
Osmond CB, Ludlow MM, Davis R, Cowan IR, Powles SB, Winter K (1979) Stomatal responses to humidity in Opuntia inermis in relation to control of CO2 and H2O exchange patterns. Oecologia (Berlin) 41:65–76
Schreiber U, Schliwa U, Bilger W (1986) Continuous recording of photochemical and non-photochemical chlorophyll fluorescence quenching with a new type of modulation fluorometer. Photosynth Res 10:51–62
Weis E, Berry J (1987) Quantum efficiency of Photosystem II in relation to ‘energy’-dependent quenching of chlorophyll fluorescence. Biochim Biophys Acta 894:198–208
Winter K (1985) Crassulacean acid metabolism. In: Barber J, Baker NR (eds) Photosynthetic Mechanisms and the Environment. Elsevier, Amsterdam, pp 329–387
Winter K, Demmig B (1987) Reduction state of Q and nonradiative energy dissipation during photosynthesis in leaves of a crassulacean acid metabolism plant, Kalanchoë daigremontiana Hamet et Perr. Plant Physiol 85:1000–1007
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Adams, W.W., Díaz, M. & Winter, K. Diurnal changes in photochemical efficiency, the reduction state of Q, radiationless energy dissipation, and non-photochemical fluorescence quenching in cacti exposed to natural sunlight in northern Venezuela. Oecologia 80, 553–561 (1989). https://doi.org/10.1007/BF00380081
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DOI: https://doi.org/10.1007/BF00380081