Algal Pigments

Abstract

A wide variety of pigments in algae allow the absorption of light energy which is then converted to chemical energy in the photosynthetic membranes. Such variety allows them to adapt successfully to environments of differing light conditions.

Keywords: algal pigments; photosynthesis; endosymbiosis; light adaptation; photosynthetic light‐harvesting systems

Figure 1.

A variety of chlorophyll/carotenoid‐binding LHCs and phycobilisomes are associated with reaction centres of photosystem I (RC1) and II (RC2): in cyanophytes (e.g. Synechococcus) phycobilisomes transfer energy initially to RC2, and LHCs are lacking; rhodophytes (e.g. Porphyridium) have Chl a/car LHCs associated only with RC1, and phycobilisomes only with RC2. In chlorophytes (e.g. Pisum) distinct Chl a/b/car LHCs are associated with each RC. In chromophytes (e.g. Cylindrotheca) distinct Chl a/c‐car LHCs occur with RC1 and RC2. In cryptophytes (e.g. Cryptomonas) phycobiliproteins in the lumen transfer energy to Chl a, but not to Chl c. Both Chl types are associated with RC1 and RC2. Dinophytes (e.g. Gonyaulax) have a luminal peridinin–Chl a complex and an integral Chl a/c complex in thylakoids.

Figure 2.

Molecular structures of chlorophylls and photosynthetically important carotenoids. Portions highlighted in red indicate the specific side‐chains of the individual chlorophylls, and the differences between lutein, peridinin and fucoxanthin.

Figure 3.

Photosynthetic pigments absorb in the visible range of the electromagnetic spectrum. (a) Spectra of chlorophylls a and b (in acetone), c1 (in diethyl ether), and d (in acetone). (b) Spectra of phycobiliproteins B‐PE (phycoerythrin), PC (phycocyanin) and APC (allophycocyanin) (in 0.1 mol L–1 phosphate buffer). These water‐soluble pigments are present in many rhodophytes and cyanobacteria. Lutein (in acetone) is a common carotenoid in green plants.

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Further Reading

Cunningham FX Jr and Gantt E (1998) Genes and enzymes of carotenoid biosynthesis in plants. Annual Review of Plant Physiology and Plant Molecular Biology 49: 558–583.

Gantt E (1996) Pigment complexes and the concept of the photosynthetic unit: Chlorophyll complexes and phycobilisomes. Photosynthesis Research 48: 47–53.

Green BR and Durnford DG (1996) The chlorophyll‐carotenoid proteins of oxygenic photosynthesis. Annual Review of Plant Physiology and Plant Molecular Biology 47: 685–714.

Jeffrey SW, Mantoura RFC and Wright DW (eds) (1997) Phytoplankton Pigments in Oceanography: Guidelines to Modern Methods. Paris: UNESCO Publishing.

Ort DR and Yocum CF (eds) (1996) Oxygenic Photosynthesis: The Light Reactions. Dordrecht: Kluwer Academic Publishers.

Rowan KS (1989) Photosynthetic Pigments of Algae. Cambridge: Cambridge University Press.

Sidler WA (1994) Phycobilisome and phycobiliprotein structures. In: Bryant DA (ed.) The Molecular Biology of Cyanobacteria, pp. 139–216. Dordrecht: Kluwer Academic Publishers.

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How to Cite close
Gantt, Elisabeth, and Cunningham, Francis X(Apr 2001) Algal Pigments. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1038/npg.els.0000323]