Flower organization

The conquest of the land by plants necessitated the development of a coating, the cuticle, that would reduce water loss. Suberin and cutin vary in their proportion of fatty acids, fatty alcohols, hydroxyfatty acids, and dicarboxylic acids. The cuticle is synthesized and excreted by the epidermis of aerial portions of the plant, such as the primary stems, leaves, flower organs, and fruits. The two major hydrophobic layers that contribute to the cuticle are composed of phenolic molecules combined with lipid polymers. Cutin is a polymer found in the outer cell wall of the epidermis, which is... 

Rosati, C. et al.. Molecular cloning and expression analysis of dihydroflavonol 4-reductase gene in flower-organs of Forsythia x intermedia. Plant Mol Biol, 35, 303, 1997. 

By growing your flowers organically—using plenty of organic matter in the soil and as a mulch, and not treating them with chemicals— you can be assured that when you drink in their glorious scents, you re not inhaling a cocktail of toxic chemical residues. 

Northern blot analysis of C/TE13 expression in C. lanceolata plants revealed accumulation of TE transcripts in a decreasing order of intensity in flowers, immature embryos, leaves and Immature seeds. Moreover, a larger number of molecular species of transcripts were detected in flowers and leaves compared with immature embryos. At present It is unclear, whether this transcript accumulation in flowers Is the result of TE expression in different flower organs e. g. young ovaries prior to the development of embryos, or whether It is associated with an as yet unknown function. 

C. Insoluble in water, soluble in organic solvents. Flavone occurs naturally as dust on the flowers and leaves of primulas. It has been prepared from o-hydroxyacetophenone and benzaldehyde. 

See also C. B. Reese, Protection of Alcoholic Hydroxyl Groups and Glycol Systems, in Protective Groups in Organic Chemistry, J. F. W. McOmie, Ed., Plenum, New York and London, 1973, pp. 95-143 H. M. Flowers, Protection of the Hydroxyl Group, in The Chemistry of the Hydroxyl Group, S. Patai, Ed., Wiley-Interscience,... 

July, 1905, commencement of flowering. The roots were now found to be richer in essential oil than the stetns. In all the organs the proportion had increased, and in the leaves it had doubled. 

In regard to the distribution of the essential oil from one organ of the plant to another, it has been established that there is a circulation of the odorous compounds from the green portions of the plant into the flowers. 

The earlier researches of Charabot have shown that the essential oil of the flowers is richer in menthone than the essential oil of the leaves. And it is in spite of a circulation of menthol, a soluble principle, from the leaf to the inflorescence, that this latter organ contains an essential oil particularly rich in menthone. It must therefore be that the menthol is there converted into menthone by oxidation. 

The differences in composition between the two essential oils examined show well, if they be compared with those which exist between the essential oils of the leaves and the inflorescences, that the distribution of the odorous principles between the leaf, the organ of production, and the flower, the organ of consumption, tends to take place according to their relative solubilities. But this tendency may be inhibited, or on the other hand, it may be favoured by the chemical metamorphoses which the substances undergo at any particular point of their passage or at any particular centre of accumulation. Thus, in the present case, some of the least soluble principles, the esters of menthol, are most abundant in the oil of the leaves, whilst another, menthone, is richest in the oil of an organ to which there go, by circulation, nevertheless, the most soluble portions. This is because this organ (the flower) constitutes the. medium in which the formation of this insoluble principle is particularly active. 

We ve discussed only open-chain compounds up to this point, but most organic compounds contain rings of carbon atoms. Chcysanthemic acid, for instance, whose esters occur naturally as the active insecticidal constituents of chrysanthemum flowers, contains a three-membered (cyclopropane) ring. 

The bright colors of flowers and the varied hues of autumn leaves have always been a cause for delight, but it was nor until the twentieth century that chemists understood how these colors arise from the presence of organic compounds with common structural features. They discovered how small differences in the structures of the molecules of these compounds can enhance photosynthesis, produce important vitamins, and attract pollinating bees. They now know how the shapes of molecules and the orbitals occupied by their electrons explain the properties of these compounds and even the processes taking place in our eyes that allow us to see them. 

The dense fluid that exists above the critical temperature and pressure of a substance is called a supercritical fluid. It may be so dense that, although it is formally a gas, it is as dense as a liquid phase and can act as a solvent for liquids and solids. Supercritical carbon dioxide, for instance, can dissolve organic compounds. It is used to remove caffeine from coffee beans, to separate drugs from biological fluids for later analysis, and to extract perfumes from flowers and phytochemicals from herbs. The use of supercritical carbon dioxide avoids contamination with potentially harmful solvents and allows rapid extraction on account of the high mobility of the molecules through the fluid. Supercritical hydrocarbons are used to dissolve coal and separate it from ash, and they have been proposed for extracting oil from oil-rich tar sands. 

Osmotic adjustment by plant cells in response to an increasing saline environment can be mediated by an alteration in intracellular concentrations of both inorganic and organic ions (Wyn Jones, 1980,1984 Aspinall, 1986 Flowers Yeo, 1986 Grumet Hanson, 1986 Moftah Michel, 1987). 

Rowland, C. Y., Blackman, A. J., D Arcy, B. R. and Rintoul, G. B. 1995. Comparison of organic extractives found in leatherwood Eucryphia lucida) honey and leatherwood flowers and leaves. J. Agric. Food Chem. 43 753-763. 

The carotenoids are the most widespread group of pigments in nature, with an estimated yield of 100 million tonnes per annum. They are present in all photosynthetic organisms and responsible for most of the yellow to red colours of fruits and flowers. The characteristic colours of many birds, insects and marine invertebrates are also due to the presence of carotenoids, which have originated in the diet. Animals are unable to synthesise carotenoids de novo, and so rely upon the diet as the source of these compounds. Carotenoids found in the human diet are primarily derived from crop plants, where the carotenoids are located in roots, leaves, shoots, seeds, fruit and flowers. To a lesser extent, carotenoids are also ingested from eggs, poultry and fish. Commercially, carotenoids are used as food colourants and in nutritional supplements (Table 13.1). Over recent years there has been considerable... 

Figure 10. Tissue specific expression of p-subunit proteins in floral tissues. Stage 3 (fully opened) flowers were collected, dissected and cell wall proteins (5 pgm) from the indicated organs isolated and analyzed for p-subunit antigen. Note the high level of expression in stigma/style and anthers/pollen and restriction of the larger antigen to stigma/style tissues. PGl lane, 1 gg of purified fruit PGl protein.

Several alkenes occur naturally in living organisms. Some of these alkenes act as hormones and control biological functions. Plants produce ethene as a hormone to stimulate flower and seed production and to ripen fruits. Ethene stimulates enzymes in the plants to convert starch and acids of unripe fruit into sugars. The enzymes also soften fruit by breaking down pectin in cell walls. 

Simon It is just because in the species that I have discussed the carpels are the last organs to develop in the centre of the flower. There are a few exceptions in other plants where the carpels are not so central. We can introduce homeotic mutants that replace carpels with sepals or petals, and the same effects are seen. 

Goodwin Presumably there is another relationship between the cell division cycle and differentiation the delimitation of successive whorls of organs in the flower. Is there anything known about how this is regulated ... 

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