|MadSci Network: Botany|
Date: Sat Nov 24 19:09:46 2001
Posted By: David Hershey, Faculty, Botany, NA
Area of science: Botany
Anthocyanins are flavonoids. A major function of anthocyanins is to provide color to most flowers and fruits. The colors can help attract pollinating animals to flowers and animals that will help disperse seeds. Anthocyanins are also thought help protect leaves from ultraviolet radiation but some botanists think that may not be true for all plant species. Anthocyanins are also thought to deter herbivores in some species.
Xanthophylls are carotenoids. The main xanthophyll in leaves is lutein. Xanthophylls are structural components of the light harvesting antenna in chloroplasts. They function as accessory pigments for harvesting light at wavelengths that chorophyll cannot, and transfer the light energy to chlorophyll. They also absorb excess light energy and dissipate it in order to avoid damage in what is termed the Xanthophyll Cycle. The xanthophyll, zeaxanthin, appears to have a role in sensing blue light which is involved in stomatal opening and in phototropism.
THE FUNCTION OF ANTHOCYANINS IN LEAVES
Anthocyanin function in leaves
Estimating anthocyanin, chlorophyll, and carotenoid concentrations using hyperspectral reflectance
Basic Photomorphogenesis - Zeaxanthin and Stomatal Opening
Gould KS, Kuhn DN, Lee DW, Oberbauer SF. 1995. Why leaves are sometimes red. Nature 378: 241-242.
Gould KS, Markham KR, Smith RG, Goris JJ. 2000. Functional role of anthocyanins in the leaves of Quintinia serrata A Cunn. Journal of Experimental Botany 51: 1107-1115.
Quỉones MA and Zeiger E (1994) A putative role of the xanthophyll, zeaxanthin, in blue light photoreception of corn coleoptiles Science 264: 558-561.
E Zeiger and J Zhu. (1998) Role of zeaxanthin in blue light photoreception and the modulation of light-CO2 interactions in guard cells Journal of Experimental Botany "49, Special Issue": 433-442.
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