Induction of anthocyanin formation and of enzymes related to its biosynthesis by UV light in cell cultures of Haplopappus gracilis

Only UV light below 345 nm stimulates anthocyanin formation in dark grown cell suspension cultures of Haplopappus gracilis. A linear relationship between UV dose and flavonoid accumulation, as found previously with parsley cell cultures, was not observed with the H. gracilis cells. Only continuous irradiation with high doses of UV was effective. Drastic increases in the activities of the enzymes phenylalanine ammonia-lyase, chalcone isomerase and flavanone synthase were observed under continuous UV light. The increase in enzyme activities paralleled anthocyanin formation.     

Light-Induced Anthocyanin Reduces the Extent of Damage to DNA in UV-Irradiated Centaurea cyanus Cells in Culture

Using suspension cultures of Centaurea cyanus L. cells, in whichthe biosynthesis of anthocyanin is induced by illumination withUV-containing white light and in which the level of pigmentcan be controlled, we examined the sensitivity of the cellsto both UV-B and UV-C irradiation and the formation of pyrimidinedimer as a result of exposure to UV light, with a special referenceto the level of accumulation of anthocyanin pigment in the cells.The sensitivity of the cells to UV-B or UV-C decreased as theiranthocyanin content increased. Furthermore, the extent of formationof pyrimidine dimers induced by irradiation with UV-B or UV-Clight was found to be reduced in cells with accumulated anthocyanin.Both the extent of resistance to UV irradiation and the reductionin the extent of formation of dimers as a result of exposureto UV light were correlated with the levels of accumulated anthocyaninpigment in the cells. The results show that anthocyanin, a kindof flavonoid, plays a role in protecting cells from the adverseeffects of UV light. (Received January 28, 1991; Accepted May 19, 1991)     

Isolation and Identification of an Anthocyanin from the Cell Suspension Culture of Poplar

During the course of the induction of many species of plant callus, it was found that callus of poplar, induced on the agar medium containing 0.5 mg per liter of 2,4-dichlorophenoxy acetic acid (2,4-D), upon exposure to white light produces an anthocyanin in its cell. The callus was inoculated into submerged cultures under light on a reciprocal shaker, and the pigment produced was isolated as pure crystals.

By the use of IR spectrum, UV spectrum and other physical and chemical methods, the anthocyanin was identified as cyanidin-3-monoglucoside (chrysanthemin).     

Reactive oxygen species produced via plasma membrane NADPH oxidase regulate anthocyanin synthesis in apple peel

Main conclusion

Solar ultraviolet irradiation regulates anthocyanin synthesis in apple peel by modulating the production of reactive oxygen species via plasma membrane NADPH oxidase instead of other pathways. The synthesis of anthocyanin in apple peels is dependent upon solar irradiation. Using 3-mm commercial glass to attenuate solar UV-A and UV-B light, we confirmed that solar UV irradiation regulated anthocyanin synthesis in apple peels after exposing previously bagged fruit to sunlight. During sunlight exposure, UV attenuation did not affect the expression of MdHY5, MdCOP1, or MdCRY2, but significantly lowered plasma membrane NADPH oxidase activity and superoxide anion concentrations. UV attenuation also reduced the expression levels of MdMYB10, MdPAL, MdCHS, MdF3H, MdDFR, MdANS and MdUFGT1, UDP-glycose:flavonoid 3-O-glycosyltransferase (UFGT) activity, and local concentrations of anthocyanin and quercetin-3-glycoside. In contrast, exogenous application of hydrogen peroxide could enhance anthocyanin and quercetin-3-glycoside synthesis. Xanthophyll cycle pool size on a chlorophyll basis was higher but its de-epoxidation was lower under direct sunlight irradiation than that under UV-attenuating conditions. This suggests that reactive oxygen species (ROS) produced in chloroplast are not major contributors to anthocyanin synthesis regulation. Inhibition of plasma membrane NADPH oxidase activity lowered the production of ROS through this mechanism, significantly inhibited the synthesis of anthocyanin, and increased the total production of ROS in apple peel under direct sunlight irradiation, suggesting that ROS produced via plasma membrane NADPH oxidase regulates anthocyanin synthesis. In summary, solar UV irradiation regulated anthocyanin synthesis in apple peels by modulating the production of ROS via plasma membrane NADPH oxidase.     

Enhancement of anthocyanin production by Perilla frutescens cells in a stirred bioreactor with internal light irradiation

Oxygen supply and light irradiation exhibited significant influence on the production of anthocyanin (red pigments) by suspended cultures of Perilla frutescens cells in a 2.6-l aerated and agitated bioreactor with a six-flat-bladed turbine. When the initial volumetric oxygen transfer coefficient (k_La) value was below 10 h⁻¹ and light was not irradiated, the anthocyanin production was never over 0.6 g/l. By modification of a gas sparger, the oxygen supply capability of the bioreactor was remarkably improved, and 1.65 g/l of anthocyanin was obtained at an enhanced k_La value of 15.4 h⁻¹. Moreover, it was found that anthocyanin accumulation at a 0.2 vvm aeration rate was higher than that at 0.1 or 0.4 vvm in the modified bioreactor, with the other cultivation conditions kept the same. Light irradiation also significantly increased anthocyanin accumulation in the stirred reactor at a low k_La value, i.e. 9.9 h⁻¹. However, a combination of irradiation with a higher oxygen supply reduced the production of anthocyanin in the bioreactor.     

Comparison of Photomorphogenic Responses to UV Light in Red and White Cabbage (Brassica oleracea L.)

Photoinhibition of hypocotyl growth in white cabbage (Brassica oleracea L., cv “Bianco Brunswick”) is controlled by UV absorbing receptor(s) and the phytochrome system, while in red cabbage (cv “Rosso Olandese tardivo invernale”) phytochrome can act without any requirement for the action of a specific UV receptor. Similar results have been obtained for the photoregulation of anthocyanin production. Twenty-four hour preirradiations with UV light or 692 nanometers light lead to the same increase in responsiveness of the system toward Pfr in a following dark period, suggesting a phytochrome promotion of subsequent light induction for both.     

Production of Anthocyanins by Vitis Cells in Suspension Culture

A large amount of anthocyanin was accumulated in the callus tissues of Vitis hybrids without light irradiation.

Culture conditions for the production of anthocyanins by Vitis cells in suspension cultures were investigated. High sucrose and low phosphate concentrations brought about a marked increase of anthocyanin formation, while high concentrations of nitrate, phosphate, and 2, 4-D repressed the pigment formation. The effects of these nutrients depended on the concentrations of coexistent ones.

Regulation of the aeration rate was important for anthocyanin formation in submerged aerated cultures and light irradiation enhanced anthocyanin formation in cultured cells.     

Wirkungsspektren der Anthocyansynthese in Gewebekulturen und Keimlingen von Haplopappus gracilis

Summary The biosynthesis of anthocyanin in tissue cultures and intact seedlings of Haplopappus gracilis is a light-dependent reaction which can be induced by blue light only. Anthocyanin appeared in all organs of the seedling.Wounding of the plant led to an increase in the content of anthocyanin due to increased anthocyanin synthesis in the cotyledons.The action spectra of anthocyanin formation in tissue cultures and intact seedlings have two peaks, one at 438 nm and the other at 372 nm. The limit of activity in the direction of longer wavelengths lies between 474 and 493 nm. Red light of short and long wavelength is ineffective in the induction of pigment synthesis. The photoreceptor of the light reaction is supposed to be a yellow pigment (flavoprotein or carotinoid). In contrast to the intact plants, isolated cotyledons and wounded seedlings are able to form anthocyanin not only in the blue region but also during irradiation with red light of high intensity. The action spectrum of anthocyanin synthesis in the isolated cotyledons has a marked maximum at about 440 nm and a second one at about 660 nm. A little activity can be observed throughout the visible spectrum. The pigment synthesis induced by red light can be completely suppressed by DCMU, an inhibitor of photosynthesis. This indicates that in the case of the activity in the red light caused by wounding chlorophyll serves as photoreceptor.The anthocyanin synthesis in tissue cultures and seedlings could not be influenced by low energy radiation in the red or in the far red region, even after induction of anthocyanin synthesis by blue light of high intensity. Therefore it seems that the phytochrome system is not involved in anthocyanin synthesis in Haplopappus gracilis.     

The ecophysiology of foliar anthocyanin

The accumulation of foliar anthocyanins can be consistently attributed to a small range of contexts. Foliar anthocyanin accumulates in young, expanding foliage, in autumnal foliage of deciduous species, in response to nutrient deficiency or ultraviolet (UV) radiation exposure, and in association with damage or defense against browsing herbivores or pathogenic fungal infection. A common thread through these causative factors is low photosynthetic capacity of foliage with accumulated anthocyanin relative to leaves at different ontogenetic stages or unaffected by the environmental factor in question. The ecophysiological function of anthocyanin has been hypothesized as: 1) a compatible solute contributing to osmotic adjustment to drought and frost stress; 2) an antioxidant; 3) a UV protectant; and 4) protection from visible light. Review of the internal leaf distribution of anthocyanin, of experimental evidence using seedlings, and of studies that directly investigated light absorption by anthocyanin and its development relative to recognized processes of photoprotection support the hypothesis that anthocyanins provide protection from visible light.     

The biogenesis of the anthocyanins. III. The role of sugars in anthocyanin formation

Anthocyanin formation in growing cultures of Spirodela is promoted by sucrose but not by glucose; conversely, growth is promoted by glucose but not by sucrose. Fructose is intermediate in both respects.In non-growing cultures, however, all three sugars are equally effective in promoting anthocyanin formation.A number of treatments which increase or decrease the anthocyanin content have parallel effects on the reducing sugar content. A plot of anthocyanin content against reducing sugar content shows a smooth relationship. Variations in the sucrose content are smaller and show no parallelism with pigmentation.It is deduced that anthocyanin may be formed independently from any of the three sugars, but that glucose is preferentially consumed for growth.Phosphate apparently does not participate in the formation of anthocyanin, and if the process does take place directly from sugars it probably does not proceed via the usual glycolytic pathway, since none of a number of glycolytic intermediates gives rise to any anthocyanin.There is some evidence for a participation of meso-inositol in the biogenesis of anthocyanin. The effects of quinic and shikimic acids appear too small for them to be considered as intermediates. Phosphate appears to be no more required with inositol than with the sugars.