Lipids plant growth activity

Fatty Acids and Lipids Although several fatty acids, esters and alcohols are known to be toxic to plant growth, their role in allelopathy is not fully investigated (3). Dihydroxystearic acid (3, 49) is the classic example known to exhibit allelopathic activity. 

In this chapter, we studied the influence of spatially-hindered phenols and plant growth regulators (PGR) on the intensity of lipid peroxidation (LPO) in membranes of mitochondria. Under stress conditions, the intensity of fluorescence of LPO products in membranes of these organelles increases 3 to 4 times. Spatially-hindered phenols and PGRs decrease the LPO intensity to the control values and maintain thereby a high functional activity of mitochondria. Prevention of dysfunction of mitochondria is associated with enhancement of the resistance of plant and animal organisms to the action of stressors. 

Thus, the studied biologically active compounds and plant growth regulators and antioxidants reduce the intensity of lipid peroxidation in membranes of mitochondria, which is the basis for maintaining a high functional activity of mitochondria and determines the protective activity of these compounds. 

Thus, the processing plant by endophytic strain B. subtilis weakened the toxic effects of cadmium ions. Each strain showed itself individually. The relative and absolute tolerance indexes of plants in almost all variants were higher when seeds were pretreated with the bacteria. On the ground of the investigations of some authors and our experimental data, we suggest that the endophytic bacteria stimulate the plant growth and increase immunity, keep up the activity of catalase and peroxidase, reduce the intensity of lipid peroxidation, stabilize cell membranes with the toxic effects of cadmium. The results are of considerable interest while developing techniques for the crop production on soils contaminated with heavy metal salts. 

Possible Mechanism of Allelopathlc Action of Water-Insoluble Plant Lipids. Many non-polar natural products with germination and growth regulation activities In laboratory tests are In pure form not sufficiently water soluble to account for their allelopathlc activities observed In the field. For this reason the notion exists that sterols and other non-polar plant constituents are not likely to play a role In allelopathlc actions, and It Is generally concluded that the bioactivity data observed In the laboratory are therefore coincidental. 

The reported (14) mechanisms of action of allelochemlcals Include effects on root ultrastructure and subsequent Inhibition of Ion absorption and water uptake, effects on hormone-induced growth, alteration of membrane permeability, changes In lipid and organic acid metabolism, inhibition of protein synthesis and alteration of enzyme activity, and effects on stomatal opening and on photosynthesis. Reduced leaf water potential Is one result of treatment with ferulic and p-coumaric acids (15). Colton and Einhellig (16) found that aqueous extracts of velvetleaf (Abutllon theophrastl Medic.) Increased diffusive resistance In soybean fGlycine max. (L.) Merr.] leaves, probably as a result of stomatal closure. In addition, there was evidence of water stress and reduced quantities of chlorophyll In Inhibited plants. 

Vitamin E is required for normal growth and reproduction. The most important natural source is a-tocopherol found in plant oils and seeds. The ester form (e.g. vitamin E acetate) can be synthesized and is used for feed supplementation. One international unit is defined as being equivalent to the activity of 1 mg DL-a-tocopherol acetate. The nutritional role of vitamin E is closely interrelated with that of selenium and is involved mainly in the protection of lipid membranes such as cell walls from oxidative damage. Although these signs are similar to those of selenium deficiency, it is not possible to substitute selenium completely for vitamin E. Both nutrients are required in the diet. 

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