role of photosynthesis on anthocyanin ..

Leaves of many angiosperm evergreen species change colour from green to red during winter, corresponding with the synthesis of anthocyanin pigments. The ecophysiological function of winter colour change (if any), and why it occurs in some species and not others, are not yet understood. It was hypothesized that anthocyanins play a compensatory photoprotective role in species with limited capacity for energy dissipation. Seasonal xanthophyll pigment content, chlorophyll fluorescence, leaf nitrogen, and low molecular weight antioxidants (LMWA) of five winter-red and five winter-green angiosperm evergreen species were compared. Our results showed no difference in seasonal xanthophyll pigment content (V+A+Z g-1 leaf dry mass) or LMWA between winter-red and winter-green species, indicating red-leafed species are not deficient in their capacity for non-photochemical energy dissipation via these mechanisms. Winter-red and winter-green species also did not differ in percentage leaf nitrogen, corroborating previous studies showing no difference in seasonal photosynthesis under saturating irradiance. Consistent with a photoprotective function of anthocyanin, winter-red species had significantly lower xanthophyll content per unit chlorophyll and less sustained photoinhibition than winter-green species (i.e. higher pre-dawn Fv/Fm and a lower proportion of de-epoxidized xanthophylls retained overnight). Red-leafed species also maintained a higher maximum quantum yield efficiency of PSII at midday (F'v/F'm) during winter, and showed characteristics of shade acclimation (positive correlation between anthocyanin and chlorophyll content, and negative correlation with chlorophyll a/b). These results suggest that the capacity for photon energy dissipation (photochemical and non-photochemical) is not limited in red-leafed species, and that anthocyanins more likely function as an alternative photoprotective strategy to increased VAZ/Chl during winter.

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They also investigated the role of photosynthesis on anthocyanin production

Flowering Plants, Shrubs and Trees

In Arabidopsis, light signaling is perceived and transduced by photoreceptors, including UV-B photoreceptor, cryptochrome 1 (CRY1) and phytochrome (PHY) A and B. The plant transcription factors HY5 and PIF3 positively regulate anthocyanin biosynthesis through direct binding to the promoters of anthocyanin structural genes, including CHS, CHI, F3H, F3'H, DFR and LDOX. However, negative regulation of pigmentation by ethylene was shown to be independent of HY5. In addition to photoreceptors, photosynthesis also contributes to the formation of anthocyanin. In turnip seedlings and non-chlorophyllous corn leaf, light-dependent anthocyanin accumulation was significantly inhibited by treatment with diuron, 3-(3,4-dicrhlorophenyl)-1, 1-dimethylurea (DCMU), a photosynthetic inhibitor., Consistent with this, in Arabidopsis, DCMU treatment of seedlings suppressed the accumulation of anthocyanin pigmentation in photosynthetically active leaf tissues in wild-type Columbia seedlings (shown in ), as well as in the ethylene-insensitive mutant etr1-1. This suppression of anthocyanin accumulation was shown to be mediated through regulation of the transcription factors of the MYB-bHLH-WD40 (MBW) complex such as PAP1, Gl3 and EGL3. Additionally, there was an inverse relationship between the activity of the MBW complex and the level of MYBL2, which inhibits the formation of active MYB complexes. Ethylene maintains anthocyanin pigmentation in Arabidopsis leaves through the regulation of MYBL2 at the transcriptional level.

23/09/2008 · Why do leaves change color and turn red

A feature of anthocyanin pigmentation during development is the transient nature of accumulation when either environmental or developmental changes render the plant more sensitive to environmental conditions. Prolonged accumulation of anthocyanin occurs only in tissues that do not have a photosynthetic carbon assimilation function and is favorable only under conditions of high light or in an arid habitat. The effects of developmental and environmental factors on anthocyanin pigmentation have been extensively reviewed in reference . Plants have evolved such temporal and spatial regulation systems in part because the accumulation and maintenance of anthocyanin involves an investment of energy that may reduce light capture and eventually carbon assimilation., Hence, the regulation of anthocyanin pigmentation seems to be intimately connected to the universal phenomenon of overall homeostasis, wherein negative reciprocity between pathways ensures that anthocyanin is synthesized and greening is suppressed during early stages of seeding growth, when the seedlings are most susceptible to light stress. Anthocyanin suppression appears to be mediated in part through the desensitization of certain structural genes and/or negative regulation of other interrelated pathways., Thus, negative regulation of anthocyanin accumulation by ethylene might be a mechanism whereby the proper balance between carbon assimilation and anthocyanin accumulation is maintained in target tissues, via the suppression of light- and sugar-induced anthocyanin pigmentation. Such a view is supported by the observation that an increase in the level of ethylene in vivo is accompanied by an increase in sugar and light dosage.

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Functional role of anthocyanins in the leaves of ..

Winsor, G., and P. Adams. 1987. Diagnosis of mineral disorders in plants. Vol.3. Glasshouse crops. Her Majesty's Stationery Office, London. 168 pp.

red cabbage contained a lot of anthocyanin, a protective pigment that does not play a large role in photosynthesis.

03/10/1997 · A Role in NPQ for Xanthophylls ..

The results of this study indicate that coloured, chlorophylless flower petals of P. hybrida are able to light energy storage that can be directly detected using photoacoustic spectrometry. The corresponding photosynthetic process (ADAPFP), as well as the usual chlorophyll photosynthesis, is accompanied by additional ATP synthesis. However, this process is chlorophylless and anoxygenic, featuring the following characteristics, which differ from those of the usual chlorophyll photosynthesis in green plant tissues:

06/03/2017 · Did you know that plants are not the only photosynthetic organisms? Test your knowledge of photosynthesis by taking the Photosynthesis Quiz.

The Ecophysiology of Foliar Anthocyanin ..

There is a big difference between shot-gun sprays and a foliar nutrient spray to treat a specific deficiency. One situation where a foliar nutrient spray might be recommended is iron deficiency. Sometimes, the upper leaves of a tomato plant may turn yellow, especially after a large number of tomatoes have been set on the plant. Foliar sprays of a solution of 0.5 to 1.0 ml of a 5% Fe solution in 1 gallon of water will usually clear up the problem. Repeated sprays might be needed. Foliar sprays of micronutrients must be done on a diagnosed basis, and care must be exercised to apply the correct amount. Foliar burn can easily occur where care is not exercised.