plant hormone


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plant hormone

any of several chemical substances produced in very low concentrations in plants, that control growth and development. They are now usually called growth substances. Plant HORMONES are produced in active MERISTEMS (e.g. root and shoot apices) from where they diffuse to other parts of the plant. A distinct contrast with animal hormonal systems is the fact that plants do not possess specific tissues for hormone production, nor a well-defined distribution system equivalent to the blood system.

Plant hormones are classified generally into several groups, discussed under separate headings: ABSCISSIC ACID, AUXINS, CYTOKININS and GIBBERELLINS.

References in periodicals archive ?
The number of functionally characterized peptide hormones now exceeds the number of classical plant hormones.
Regarding gibberellins, this plant hormone influences germination, seedling growth, stem elongation, leaf development, bud outgrowth, flower induction, and xylem expansion (Gabriele et al.
16] were shown that plant hormones in general and auxins in particular, can significantly affect the uptake and further transport of nutrients within plants by regulating the sink action of developing tissues.
The team, which wanted to determine which GSs and their products actually boost the enzyme levels when broccoli is treated, found that one way to increase GSs is to spray a plant hormone called methyl jasmonate on broccoli.
Plant Hormone Signal Transduction: A Brief Overview
The theory that the plant hormone auxin could play a role in plants bending toward a light source was first proposed in 1937 by the Dutch researcher Frits Went in the Cholodny-Went model.
Plant hormone auxin is involved in the control of several and distinct processes, such as embryogenesis, all types of organogenesis, root meristem maintenance, vascular tissue differentiation, hypocotyl and root elongation, apical hook formation, apical dominance, fruit ripening, growth responses to environmental stimuli, and others [1, 2].
But "forced" rhubarb develops faster abroad because it is often sprayed with harmless plant hormone gibberellic acid.
The active ingredient, a natural plant hormone called ethephon, causes the fertilized flowers to fall off so fruits can't develop.
The liquor is mixed with a tiny quantity of Gibberellic acid, an important plant hormone that improves seed germination and plant growth as well as size, and then with water.
In this text, 28 international researchers examine the most current genetic, biochemical, analytical and chemical biological approaches for understanding and dissecting plant hormone action.