Regulation of pigment biosynthesis in flowers

Type :

Presentation

Pages :

9 pages

Format :

.doc

Published date :

11/19/2008

Category :

Science & technology

Sub category :

Biology

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Summary :

Introduction.
Regulation of pigment biosynthesis in flowers.
1. The induction of the pigment biosynthetic genes.
2. Adequate carbohydrate level.
3. Post-transcriptional regulation.
4. Post-transcriptional translational mechanisms.
Regulation of flavonoid production in flowers.
1. Regulation of the production of flavonoid precursors.
2. TFs regulating anthocyanin production.
3. Regulation of the production of other floral flavonoid pigments/co-pigments.
Genetic modification of flower pigmentation.
Flavonoids.
Carotenoids.
Betalains.
Conclusion.

Abstract

Flower color, along with fragrance, floral shape and nectar reward, is important to the interaction between plants and pollinators; and preferences towards specific colors are exhibited by pollinators, whether they are birds, bees, butterflies or other insects. Commonly contributing to floral phenotypes are color combinations and patterning such as distinctive spots on the flower 'lip' or pigment lines in the flower tube. These may provide more specific signals within the flower, e.g. acting as nectar guides to insects. In an extraordinary example of pollinator signaling, the flowers of the orchid genus Ophrys use color, scent and shape to mimic female bees, causing the male bee to attempt copulation, thus achieving pollination. The major pigments responsible for flower color are carotenoids, flavonoids and betalains. Although other pigment types such as chlorophylls, phenylphenalenones and quinochalcones can generate flower colors, their occurrence is rare. Carotenoids are lipid soluble, plastid-located terpenoids present in photosynthetic plants, algae and bacteria. For pigmentation of flowers (and fruits), carotenoids accumulate to high levels in specialized plastids called chromoplasts. These pigments participate in the harvesting and dissipation of light energy in chloroplasts, protecting the photosynthetic machinery from photo-oxidation.