Cellulose, growth regulators

One strategy to the enhance CO2 fixation in woody plants is to enhance the expression of genes required for cellulose deposition, which should enhance plant growth either by cell wall or just cellulose deposition. We have already isolated the full length of cDNAs for three kinds of cellulases, XET and expansin as plant cell growth regulators, and for two kinds of cellulose synthases and suCTOse synthase as a system of cellulose synthesis, as summarized in Table 2. If cellulose deposition is increased by the increased activity of each enzyme in the transformants of Arabidopsis, the gene can be introduced to woody plants to determine the cellulose deposition. 

The reversal of enantiomeric elution order for the polysaccharide CSP was first reported by Okamoto et al. in 1991. They found that the reversal of the elution order of the enantiomers on a modified cellulose column was associated with changes in the mobile phase modifiers during the investigation of the direct chromatographic enantioseparation of pyriproxyfen, an insect growth regulator. If one can find such phenomena, although very rare in HPLC, it will be important to understand the reasons for this behavior and to anticipate when such inversions of elution order are likely to occur. 

According to another method, ABA was determined by HPTLC on silica gel plates with fluorescent labeling. The mobile phase was composed of toluene-ethyl acetate-acetic acid (25 15 2) (97b). Sumilarv (pyriproxyfen), a new insecticide growth regulator, was studied by TLC. The enantiomers were separated on a cellulose coated layer. The best separation was achieved when cellulose tris(4-methylbenzoate) coated silica was the stationary phase and hexane-hexanol (9 1) the mobile phase (97c). 

Prospects for Economic Benefit. As of May 1992, EPA registrations of biorationals included 14 pheromones, 6 plant growth regulators, 13 floral lures, 5 natural insect growth regulators, and 4 others (including diallyl sulfoxide, carboxymethyl cellulose, soybean oil as a miticide). 

Phenylalanine, tyrosine, and tryptophan are converted to a variety of important compounds in plants. The rigid polymer lignin, derived from phenylalanine and tyrosine, is second only to cellulose in abundance in plant tissues. The structure of the lignin polymer is complex and not well understood. Tryptophan is also the precursor of the plant growth hormone indole-3-acetate, or auxin (Fig. 22-28a), which has been implicated in the regulation of a wide range of biological processes in plants. 

The formation of plant cellulases has been found to be closely regulated by different growth hormones, particularly auxin (6,11), steroids (12), or ethylene gas (13). The hormones act in different tissues under different circumstances, and they seldom lead to such high cellulase activity that there is a net decline in total cellulose. Indeed, cellulose biosynthesis usually continues even while partial hydrolysis occurs, and net cellulose deposition often keeps pace with growth under all of these conditions (14). 

Moisture absorbers. Based on cellulose fibres or a cross-linked polymer hydro gel to remove the drip from fresh meat resulting in a better appearance of the food. In some packaging, mixtures of herbs are added to the absorbing pad to avoid microbiological growth in the drip juice and as a result a longer shelf life. For dry foods, e.g., biscuits, moisture regulators based on silica gel or molecular sieve may be employed. 

T t has been reported that fungal cellulases are induced enzymes and that cellulose preparations induce cellulolytic activity while easily assimilable carbon sources give the best fungal growth but less production of enzyme activity (9,12, 14). For example, Horton and Keen (10) found that 7.5 X 10"3M D-glucose repressed the synthesis of cellulase to a basal level in Pyrenochaeta terrestris and suggested that cellulase synthesis was regulated by an induction-repression mechanism. 

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