Photosynthesis carotenoids

In some instances, additional functions are the attraction of pollinating or seed-dispersing animals, for example, by colored compounds such as betalains (within the Centrospermae), anthocyanins, carotenoids, and flavonoids or by fragrances such as terpenes, amines, and aldehydes 15,17). Physiological roles, such as UV protection [by fiavonoids or cou-marins 4,17)], nitrogen transport or storage 14,36,37), or photosynthesis (carotenoids), may be an additional function. 

Bleaching Herbicides. Membrane-based modes of herbicidal action relevant to photosynthesis (37) include those of inhibitors of carotenoid biosynthesis, eg, norflura2on, diftmon, y -phenoxyben2amines inhibitors of chlorophyll biosynthesis, eg, oxadia2on, DTP or... 

Green, B. R., and Dnrnford, D. G., 1996. The chlorophyll-carotenoid proteins of oxygenic photosynthesis. Annual Review of Plant Physiology and Plant Molecular Biology 47 685—714. 

Siefermann-Harms, D. (1985). Carotenoids in photosynthesis. I. Location in photosynthetic membranes and light-harvesting function. Biochimica Biophysica Acta, 811, 325-55. 

BOUVIER F, d harlingue A, BACKHAUs R A, KUMAGAi H and CAMARA B (2000) Identification of neoxanthin synthase as a carotenoid cyclase pmalog , FEBSLetters, 267, 6346-52. BRAMLEY P M (1993) Inhibition of carotenoid biosynthesis , in Yoimg A J and Britton G, Carotenoids in Photosynthesis, London, Chapman and HaU, 127-59. 

Green, B.R. and Dunford, D.G., The chlorophyll-carotenoid proteins of oxygenic photosynthesis, Anmi. Rev. Plant Physiol. Plant Mol. Biol., 47, 685, 1996. 

Carotenoids are essential to plants for photosynthesis, acting in light harvesting and especially in protection against destructive photooxidation. Without carotenoids, photosynthesis in an oxygenic atmosphere would be impossible. Some animals use carotenoids for coloration, especially birds (yellow and red feathers), fish and a wide variety of invertebrate animals, where complexation with protein may modify then-colors to blue, green or purple. ... 

Carotenoids protect photosynthetic organisms against potentially harmful photooxidative processes and are essential structural components of the photosynthetic antenna and reaction center complexes. Plant carotenoids play fundamental roles as accessory pigments for photosynthesis, as protection against photooxidation, and... 

The photoprotective role of carotenoids is demonstrated in plant mutants that cannot synthesize essential leaf carotenoids. These mutants are lethal in nature since without carotenoids, chlorophylls degrade, their leaves are white in color, and photosynthesis cannot occur. Generally, the carotenoids are effective for visible light but have no effects in ultraviolet, gamma, or x-radiation. The reactions are listed as follows ... 

Young, A. and Britton, G., Carotenoids in Photosynthesis, Chapman HaU, London,... 

Niyogi, K.K., Safety valves for photosynthesis, Curr. Opin. Plant Biol. 3, 455, 2000. Pogson, B.J. and Rissler, H.M., Genetic manipulation of carotenoid biosynthesis and photoprotection, Philos. Trans. R. Soc. Lond B 355, 1395, 2000. 

Molecular, spectroscopic, and functional genomics studies have demonstrated the remarkable similarity among the components of the photosynthetic machinery of cyanobacteria, algae, and plants. These organisms also share the need to balance the collection of energy for photosynthesis with the threat of photodestruction. Carotenoids are central to attaining this balance. 

Fucoxanthin, lutein, neoxanthin, violaxanthin, and zeaxanthin are the most common xanthophylls on our planet. They are found in the photosynthetic machinery of algae (fucoxanthin) and higher plants (Figure 7.1). Interestingly, lutein and zeaxanthin have also been found in the retina of humans and some primates (Khachik et al., 1997 Landrum and Bone, 2001). It is likely that these carotenoids possess some universal photophysical properties essential for both photosynthesis and vision (Britton, 1995). 

Gradinaru, C.C., Stokkum, I.H.M., van Grondelle, R., and van Amerongen, H. 1998. Ultrafast absorption changes of the LHC-II carotenoids upon selective excitation of the chlorophylls. In Photosynthesis Mechanisms and Effects, ed. G. Garab. Dordrecht, the Netherlands Kluwer Academic Publishers. 

Koyama, Y., F. S. Rondonuwu, R. Fujii, and Y. Watanabe. 2004. Light-harvesting function of carotenoids in photosynthesis The roles of the newly found 1B state. Biopolymers 74 2-18. 

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