Cuticle characteristics

GOODWIN, S.M., KOLOSOVA, N., KISH, C.M., WOOD, K.V., DUDAREVA, N., JENKS, M.A., Cuticle characteristics and volatile emissions of petals in Antirrhinum majus. Physiol. Plant, 2003,117,435-443. 

The uptake of organic contaminants by plants from biosolids-amended soil depends on the physicochemical properties of organic compoimds and the physiology of plants [92-95]. Plant uptake of organic chemicals and their distribution within plants have been shown to be affected by (1) the organic chemicals physicochemical properties, including solubility, vapor pressure, octanol-water partition coefficient Kow)> and Henry s law constants (iC ), (2) environmental conditions such as temperature, air disturbance and soil organic matter content, and (3) plant characteristics, for example the shape of the leaves, type of root system, and lipid and cuticle characteristics and contents [94]. 

A comparison of Tables I and II shows that the major coal measures of the world were derived from several quite different floristic assemblages. Thus the plants that gave rise to coals in Europe and the east and midwest of North America in the Carboniferous were part of a complex flora that included ferns, seed ferns, horsetails, lycopods and conifer precursors. Except for the conifer precursors, lignified xylem tissues tended to be minimal in these plant groups and unusually large leaves with extensive waxy cuticles were characteristic of three of the groups. 

The three Squat (sqt) mutants have a characteristic dominant-dumpy/ recessive-roller phenotype, and of the two genes characterized sqt-1 and sqt-3), both encode cuticle collagens (Kramer, 1997). 

Niche The section of the environment with which a particular property of the chemical product interacts is referred to as niche. For example, a pesticide can have as the environment the plant, the atmosphere, and the human beings. The pesticide interacts with the environment through its properties. There are different kinds of interaction depending on the niche. For example, some properties such as the contact area depend on the surfactant characteristics and the surface of the leaf. The niche is the surface of the leaf. The absorption of the pesticide depends on the characteristics of the layers, like the cuticle [25], In this case, the niche consists of the layers of the plant s leaves. Also, the diffiisivity of the active product in the layers of the plant leaves corresponds to a property that depends on the environment-product interaction. Some other pesticide properties, such as solubility of the active agent in the solvent, do not depend on the environment. 

Terrestrial BMOs have also been widely used for monitoring environmental contaminants. In particular, the lipid-like waxy cuticle layer of various types of plant leaves has been used to monitor residues of HOCs in the atmosphere. However, some of the problems associated with aquatic BMOs apply to terrestrial BMOs as well. For example, Bohme et al. (1999) found that the concentrations of HOCs with log KoaS < 9 (i.e., those compounds that should have attained equilibrium) varied by as much as 37-fold in plant species, after normalization of residue concentrations to levels in ryegrass (Lolium spp.). These authors suggested that differences in cuticular wax composition (quality) were responsible for this deviation from equilibrium partition theory. Other characteristics of plant leaves may affect the amount of kinetically-limited and particle-bound HOCs sampled by plant leaves but to a lesser extent (i.e., <4-fold), these include age, surface area, topography of the surface, and leaf orientation. 

Many studies have provided evidence that pheromones on the silk and/or the cuticle of females stimulate courtship or related behaviors in males, as do the few pheromones that have been fully identified to date. Contact with the pheromone and with silk or cuticle is usually necessary to evoke the proper courtship responses. Olfactory cues, such as those in A. aperta, may release courtship when the male is in contact with silk. There are insufficient data to draw conclusions about which classes and types of chemical might typically be used for the various kinds of pheromone, particularly as the few identified pheromone structures vary widely in polarity, volatility, and other chemical characteristics. 

The physical or petrographic components of coal are defined or described in various ways. In one system, which depends on microscopic observation, the principal components are called exinite, vitrinite, micrinite, and fusinite. Transparency of these in a thin section decreases in that order, whereas reflectance from polished surface increases in the same order. Vitrinite, the major component of most coals, occurs in bands or strands and is usually uniform in appearance, though sometimes shows cell structure exinite consists of the remains of plant spores, pollen, and cuticles with characteristic shape micrinite occurs in very fine granular form or massive structureless, irregular form fusinite shows characteristic fibrous, cellular structure. Semifusinite is transitional between vitrinite and fusinite. On a macroscopic scale, vitrain and... 

There is a seemingly endless variety of fatty acids, but only a few of them predominate in any single organism. Most fatty acid chains contain an even number of carbon atoms. In higher plants the C16 palmitic acid and the C18 unsaturated oleic and linoleic acids predominate. The C18 saturated stearic acid is almost absent from plants and C20 to C24 acids are rarely present except in the outer cuticle of leaves. Certain plants contain unusual fatty acids which may be characteristic of a taxonomic group. For example, the Compositae (daisy family) contain acetylenic fatty acids and the castor bean contains the hydroxy fatty acid ricinoleic acid. 

Cotton. Cotton is furnished by the down surrounding the seeds of various species of Gossypium. This fibre, which is unicellular and closed at only one end, is always isolated, and appears under the microscope as a ribbon twisted at intervals on its own axis like a spiral (Fig. 68, Plate VI). The wall is comparatively thin and sometimes somewhat raised like a rim the lumen is wide—three or four times as wide as the walls. This lumen is mostly empty, but sometimes contains granulations representing the original protoplasm in a dried state. The cotton fibre, which consists solely of cellulose, is coated in the raw state with a very thin cuticle, which is readily seen in a dry microscopic preparation. When raw cotton is treated with ammoniacal cupric oxide solution, whilst the cellulose of the fibre first swells and then dissolves, the cuticle remains almost intact, so that the fibres assume characteristic microscopic forms. The section of the cotton fibre (see Fig. 69, Plate VI) is elliptical, curved or reniform, with a fissure-like lumen. 

Chaumat, E., Charnel, A., (1991) Sorption and permeation to phenylurea herbicides of isolated cuticles of fruit and leaves. Effect of cuticular characteristics and climatic parameters. Chemosphere 22, 85-97. 

Bagneres, A.-G and Morgan, E. D. (1991). The postpharyngeal glands and the cuticle of Formicidae contain the same characteristic hydrocarbons. Experientia, 47, 106-111. 

We know the most about cuticular hydrocarbons, because they are abundant and because it is relatively easy to isolate and identify them. They are also the most hydrophobic lipid components, and so should provide the best barrier to water-loss. -Alkanes isolated from insect cuticles typically have chain lengths of 20-40 carbons. These can be modified by insertion of cis double bonds, or addition of one or more methyl groups. Relatively polar surface lipids include alcohols, aldehydes, ketones and wax esters (see Chapter 9). Given this diversity, is it possible to predict lipid phase behavior (and, by extension, waterproofing characteristics) from composition alone If so, a large body of literature would become instantly interpretable in the context of water balance. Unfortunately, this is not the case. 

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