Abstract
A preparation of photochemically active chloroplasts of Fucus was added to a low-salt medium with high osmolarity (HEPES AMPD buffer, 1M sorbitol). The rate of DCIP reduction (DCIPr) and the variable fluorescence (Fv) of these phaeoplasts were measured and compared with the same activities in spinach chloroplasts. A study of the influence of mono- and divalent-cations showed that salt effects on PS II activity also exist in Fucus.
-
(i)
Mg++ action on Fv is similar, although noticeably weaker in Fucus than in spinach chloroplasts.
-
(ii)
Na+ has no effect on Fv of Fucus chloroplasts, but its influence on DCIPr is more pronounced than in spinach.
-
(iii)
Mg++ influence on DCIPr is largely dependent upon excitation energy. In subsaturating light (100\2-1000 W m\t-2), Mg++ stimulation increases up to 100 mM, almost doubling the level. In very low wight conditions (3Wm\t02), however, this stimulation saturates at about 10 mM; higher concentrations are no longer effective but do not quench DCIPr noticeably, unlike the case in spinach.
Therefore, cations act through similar pathways on Fucus as on spinach isolated chloroplasts but the effects on PS II centers are preponderant in Fucus whereas the modifications in non-radiative decay or pigment array size are weaker.
Similar content being viewed by others
References
Anderson JM and Barrett J (1979) Chlorophyll-protein complexes of brown algae: P 700 reaction centre and light-harvesting complexes. In Chlorophyll organization and energy transfer in photosynthesis, Ciba Foundation, Symposium 61, pp 81–96. Elsevier North-Holland.
Arntzen CJ (1978) Dynamic structural features of chloroplast lamellae. In Sanadi R and Vernon L. eds current topics in bioenergetics, Vol. 8, pp. 111–160. New York: Academic Press.
Baker NR (1978) Effect of high cation concentrations on photosystem II activities Plant Physiol 62: 889–893.
Barrett J and Anderson JM (1977) Thylakoid membrane fragments with different chlorophyll a, chlorophyll c and fucoxanthine compositions isolated from the brown seaweed Ecklonia radiata. Plant Sci Lett 9: 275–283.
Berkaloff C and Duval JC (1977) Cation induced fluorescence changes in brown algae isolated chloroplasts. 4th Int Congr on Photosynthesis, Reading, pp. 29–30.
Berkaloff C and Duval JC (1980) Correlated influence of cation concentration and excitation intensity on PS II activity-I. Influence of high salt concentration on spinach chloroplast activity. Photosynthesis Res 1: 115–125.
Burke JJ, Ditto CL and Arntzen CJ (1978) Involvement of the light-harvesting complex in cation regulation of excitation energy distribution in chloroplasts. Arch Biochem Biophys 187: 252–263.
Emerson R and Rabinowitch E (1960) Red drop role of auxiliary pigments in photosynthesis. Plant Physiol 35: 477–485.
Goedheer JC (1970) On the pigment system of brown algae. Photosynthetica 4: 97–106.
Goehdeer JC (1973) Chlorophyll a forms in Phaeodactylum tricornutum: comparison with other diatoms and brown algae. Biochim Biophys Acta 314: 191–201.
Mills JD and Barber J (1978) Fluorescence changes in isolated broken chloroplasts and the involvement of the electrical double layer. Biophys J 21: 257–272.
Nordhorn G, Weidner M and Willenbrink J (1976) Isolation and photosynthetic activities of chloroplasts of the brown alga Fucus serratus L. Z Pflanzenphysiol 80: 153–165.
Prezelin BR and Haxo FT (1976) Purification and characterization of peridin-chlorophyll a-proteins from the marine dinoflagellates Glenodinium sp. and Gonvaulax polvedra. Plants 128: 133–141.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Berkaloff, C., Duval, J.C. Correlated influence of cation concentration and excitation intensity on PS II activity-II. Comparative study between green plant and brown-alga chloroplasts. Photosynth Res 1, 127–135 (1980). https://doi.org/10.1007/BF00018229
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00018229