Natural plant growth regulators examples

However, it is not only the first generation derivatives of individual cresols but secondary and even tertiary derivatives that have proved to be very important plant growth regulators or agrochemicals apart from their uses as household insect and pest repellents. Synthetically made pyrethroids which are replacing more costly natural pyrethrum or pyrethrins are one such example. 

Natural Products as Inducers of Insect Resistance. Plant growth regulators have been shown to increase the biosynthesis of certain secondary plant constituents that in turn decrease plant attack by insects. -Naphthaleneacetic acid, for example, elicits increased terpene biosynthesis in citrus, thus decreasing attack by fruit flies. The approach of using both natural and synthetic plant growth regulators may continue to find applications in insect control. 

Fatty primary alcohols with similar aliphatic chains to fatty acids tend to occur in the free state in tissues at low concentrations only, but they may be of some metabolic importance as precursors of alkyl lipids, as plant growth regulators and as insect pheromones, for example. In addition, they are found in esterified form in wax esters, which are substantial components of many natural materials. Secondary alcohols may be present in plant surface waxes, together with aliphatic diols which are common constituents of skin lipids. In mammalian tissues, the primary alcohols are saturated or monoenoic, but never di- or polyunsaturated in wax esters of marine origin, the alcohol constituents are often closely related in structure to the fatty acids from which they may derive biosynthetically. The occurrence, chemistry and metabolism of fatty alcohols [577] and their chromatographic properties [577,579] have been reviewed. 

Information concerning the metabolic function of unusual naturally occurring plant constituents might be used to develop new growth regulators. An example of a development that arose in this way began with the observation by Tolbert (143) that as much as 30% of the total soluble phosphorus in plant roots, and sometimes in the leaves,... 

There are hve broad chemical classihcations or categories of pesticides (four for synthetic pesticides and one for natural or plant-derived pesticides). Each of the following hve chemi-cal/biological categories of synthetic and harvested/extracted natural pesticides and growth regulators includes examples of commercial pesticides ... 

Indoleacetic acid (4.82), one of the natural growth-regulators of plants, is an example of a substance whose powerful action is abolished by the insertion of a methyl-group in the 2-position. On the other hand, in the K family of vitamins, e.g. menaphthone (2.33), the presence of a methyl-group in the 2-position is absolutely essential for biological activity (see also below). 

Biologically active natural products can be considered to be bioregulators, the name modeled in part on the plant growth hormones that were shown to regulate various plant growth and development processes Today, the levels required for activity are ever smaller and smaller For example, the pheromones have been found to be active at picogram concentrations and below ... 

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