Storage tissues

The tetrasaccharide stachyose [470-55-3] which contains an additional (1 — 6)-1inked a-D-galactopyranosyl unit, is almost as widely distributed as raffinose, but is present in even lower concentrations. Although raffinose and stachyose occur in all parts of plants, they are concentrated in storage tissues, eg, sugar beets and beans, and leaves for the most part. 

The seeds of dicotyledonous plants have two cotyledons, or seed leaves, which are part of the embryo. The cotyledons usually are the main storage tissue, although in some plants (such as castor bean) the endosperm also has a storage function. During development in the field, seeds gradually accumulate storage oils, proteins and carbohydrates (Table 3.1). In the seed, the cotyledon structure is relatively simple. The remainder of the embryo, the embryonic axis, consists mostly of undifferentiated cells, but provascular tissue can be detected that develops into vascular tissue in the seedling. 

Fruits and vegetables Potato, carrot Edible, proteins stable in storage tissues Must be cooked before consumption (potato), high starch content (potato)... 

Le Maguer and Yao (1995) presented a physical model of a plant storage tissue based on its cellular structure. The mathematical equivalent of this model was solved using a finite element-based computer method and incorporated shrinkage and different boundary conditions. The concept of volume average was used to express the concentration and absolute pressure in the intracellular volume, which is discontinuous in the tissue, as a... 

Tools have recently been developed that should enable identification of the catalytic subunits of the plasma membrane / -(l,3)-glucan synthase from red beet storage tissue and other plant sources. These include an efficient procedure for solubilization and enrichment of this enzyme using the detergent CHAPS, generation of antibodies, and use of affinity labels such as UDP-pyridoxal. 

Histamine metabolism differs from that of classical neurotransmitters because histamine is so widely distributed in the body. The highest concentrations in human tissues are found in the lung, stomach, and skin (upto 33 ug/g tissue). Histamine metabolic pathways are simple histamine is produced from histidine in just one step (see figure 4.11). The principal production takes place in the mast cells of the peritoneal cavity and connective tissues. The gastric mucosa is another major storage tissue. Histamine can be found in the brain as well. 

Many of the same conclusions may be drawn from results with synthetic auxins as from indole-3-acetic acid water intake increased, there was a lessening of the downward translocation of photosynthate with temporary increases of soluble carbohydrates in the leaves, and alterations appeared in the metabolic ratq and direction and in enzyme activity. However, the direct site of action is not known, and many of the effects are puzzling. n-Fructose oligosaccharides in artichoke and chicory storage-tissue were diminished by 70% (calculated on the content of dry matter) in 6 days... 

Vaughan, D. (1967a).The stimulation of invertase development in aseptic storage tissue shces by humic acids. Soil Biol. Biochem. 1,15-28. 

Yang, S.F. Pratt, H.K. In Biochemistry of Wounded Plant Storage Tissues, ed G. Kahl, 1978, de Gruyter, Berlin. In press. 

The basic characteristics of B deficiency show that the youngest leaves are the first affected, steins are short, severely affected plants liable to have a shrunken appearance, growing points die, root growth is impaired, fruit formation is irregular and the fruits are deformed, and necrotic and watery patches develop in storage tissue. Although plants require B for normal development, additions must be small or boron toxicity will result. Plants greatly vary in their tolerance to boron. 

The GBSS in leaves can be differentiated from those observed in storage tissue. As has been shown, the amylose content of starch can vary from 11% to 37% in storage tissue.203 In leaf or transistory starch, the amylose content is less than 15%. In pea, leaf starch amylose has a greater molecular weight than does storage starch... 

Tuber structure in cross section from exterior to interior can be separated into the epidermis, cortex, outer medulla, inner medulla, and pith (Mazza, 1985). Relatively little is known about the temporal sequence of cell division and differentiation leading up to bulking. Sink capacity is a function of the combined vacuolar volume of the tubers, the location of fructan synthesis and storage within the cells (Darwen and John, 1989 Keller et al., 1988 Pollock, 1986). Vacuolar volume is a function of cell size and number. The size of individual cells within the tuber varies with tissue type cortex (286 cells per 10 mm2), extension zone (145 cells per 10 mm2), storage tissue (85 cells per 10 mm2), and pith (149 cells per 10 mm2) (Schubert and Feuerle, 1997). The extent that cell number and size increases after the initial formation of the tuber has not been adequately documented. 

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