In Flower Coloration

The colour of the flowers of many plants show a strong dependence on the nature of the soil, whether this be its pH or the presence of other ions such as trace metals. The mechanism for this change in colour has been elucidated for the Japanese morning 

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Frias L. D., Godoy, R., Iturra, P., Koref-Santibanez, S., Navarro, J., Pacheco, N. and Stebbins, G. L. 1975. Polymorphism and geographic variation in flower color in Chilean populations of Eschscholzia califomica. Plant Syst. Evol. 123 185-198. 

T. Onozaki, M. Mato, M. Shiata and H. Ikeda, Differences in flower color and pigment composition among white carnation (Danthus caryophyllus L.) cultivars. Sci. Hort. 82 (1999) 103-111. 

The W1 locus encodes flavonoid 3 5 -hydroxylase F3 5 H) [21]. F3 5 H diverts metabolic flux into the blue delphinidin branch of anthocyanin biosynthesis (Fig. 4.1). In the absence of F3 H activity (f), Wi and recessive wl give imperfect black and buff seed colors, respectively [10]. However, in black seeds, F3 H (T) phenotypically masks Wl. In contrast to its role in seeds, Wl has a prominent role in flower colors, as delphinidin-based anthocyanins are the major pigments in purple soybean flowers [22, 23]. Interestingly, F3 5 H is expressed at very low levels in flowers and seeds [21]. This suggests that, out of the two branch-point genes (i.e., F3 H and F3 5 H), it is the strong expression of F3 H in seed coats and weak expression in the flowers that determines preferential accumulation of cyanidin-based and delphinidin-based anthocyanins in these respective tissues [21]. 

To date, published results are available for only one of the AAT cDNAs, the Dv3MaT, which was overexpressed in P. hybrida. Although the transgenics produced malonylated anthocyanins in the petals that were novel to P. hybrida, no change in flower color occurred.Modification of the activity of anthocyanin OMTs has been reported only in the patent literature (International Patent Application WO03/062428). 

Clitoria ternatea contain mainly ternatins (polyacylated delphinidin 3,3, 5 -triglucosides) and preternatins. The change in flower color from blue to mauve in this species is caused by lack of (polyacylated) glucosyl substitutions at both the 3 - and 5 -positions of the ternatins. 

The Papaver Somniferum is an annual herb that 3 to 5 tall with wide many-petaled flowers. This plant produces copious amounts of a viscous sap. Opium poppy has been cultivated for several thousand years and many cultivations have resulted, differing in flower color, opium production, color of seeds, oil content of seeds, and cultural requirements. Many variants are named, the best known are the "White Poppy" and the "Black Poppy", named for color of seed. "White Poppy" has white to silvery-gray flowers, white seeds, and the capsule is somewhat flattened both at top and bottom. "Black Poppy" usually has violet flowers, with seeds being a slate color, and the seed capsule is smaller and more globular. 

Fisher R, Budde I, Hain R (1997) Stilbene synthase gene expression causes changes in flower color and male sterility in tobacco. Plant J 11 489-498... 

Carotenoids are natural pigments characterized by a tail-to-tail linkage between two C20 units and an extended conjugated system of double bonds. They are the most widely distributed of the substances that give color to our world and occur in flowers, fruits, plants, insects, and animals. It has been estimated that biosynthesis from acetate produces approximately a hundred million tons of carotenoids per year-. The most familiar-carotenoids are lycopene and (3-carotene, pigments found in numerous plants and easily isolable from ripe tomatoes and canots, respectively. 

Betalains are largely confined to higher plants belonging to species under families of the order Caryophyllales, although they are also found in some fungi [14]. The pigments may be found in flowers, roots, and fruits of suitable species. Betacyanins do not co-occnr with anthocyanins, which they resemble closely in color it has been specnlated that they may have similar functions [14]. 

Zsila, F., J. Deli, and M. Simonyi. 2001a. Color and chirality Self-assemblies in flower petals. Planta 213 937-942. 

Many gardening books will state that the acidity of the soil affects the color of certain varieties of hydrangeas. The soil pH affects the availability of aluminum in the soil and thereby indirectly affects the flower color. A low pH or acidic conditions will yield blue blooms pink blossoms will be favored by a higher pH or alkaline conditions. A purple color is the result of a more moderate pH level. Potting soils with a high level of peat moss will produce blue hydrangeas. Areas... 

Under these conditions, blue flowers can be achieved as a metal complex of anthocyanin (called a metalloanthocyanin) is stabilized through the association of a metal ion with two hydroxy groups oriented ortho to one another on the anthocyanin ring, as illustrated in Fig. 9.4.3J2 In basic solution, the structure of the anthocyanin (Fig. 9.4.4) no longer has ortho-oriented hydroxy groups. Metal complexation is no longer possible, and the flower color appears red. 

Iwashina T, Githiri SM, Benitez ER et al (2007) Analysis of flavonoids in flower petals of soybean near-isogenic lines for flower and pubescence color genes. J Hered 98 250-257... 

Iwashina T, Oyoo ME, Khan NA et al (2008) Analysis of flavonoids in flower petals of soybean flower color variants. Crop Sci 48 1918-1924... 

Markham KR, Bloor S J, Nicholson R et al (2004) Black flower coloration in wUd Lisianthius nigrescens its chemistry and ecological consequences. Z Namrforsch C 59 625-630... 

We know of thousands of flavonoids. They have a C6-C3-C6 skeleton and are responsible for the bright colors in flowers. The bitter taste in citrus fruits is caused by flavonone glycosides. 

Recently, mutation spectrum of flower color and flower shape of carnation was also investigated by Okamura et al. [108]. In the carnation variety Vital (spray-type, cherry pink flowers with frilly petals) tested, flower color mutants such as pink, white, and red were obtained by X-ray irradiation, whereas the color spectrum of the mutants obtained by carbon ion irradiation was wide such as pink, light pink, salmon, red, yellow, and complex and striped types. Furthermore, many kinds of round shape of petals were induced in addition to flower colors. These indicate that ion beams can induce novel flower color and shape with high frequency. 

Table 3 Mutation Spectrum of Flower Color in Chrysanthemum...

Other Plants. As already described in Mutation Spectrum, complex and striped types of flower color have been obtained in chrysanthemum. A higher mutation frequency... 

The uvil-uvi4 mutants were induced from 1280 Mj, and the ast and frll mutants were obtained from the oflfspring of 1488 Mi seeds. As ion beams showed high induction of mutation of the known loci such as tt, gl, hy, it would be true that ion beams can highly induce not only known mutants but also novel mutants. In chrysanthemum and/or carnation, complex and striped flower color and new flower-shape mutants that have never been induced by low-LET radiation have been produced, indicating that ion beams could induce various kinds of mutants on the similar phenotypes. In conclusion, the character-... 

Honda, T. and Saito, N., Recent progress in the chemistry of polyacylated anthocyanins as flower color pigments. Heterocycles, 56, 633, 2002. 

Dangles, O., Saito, N., and Brouillard, R., Kinetic and thermodynamic control of flavylium hydration in the pelargonidin-cinnamic acid complexation. Origin of the extraordinary flower color diversity of Pharbitis nil, J. Am. Chem. Soc., 115, 3125, 1993. 

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