Hormones plant growth

C12H20O4. M.p. 165°C. A plant growth hormone, which is produced in damaged plant tissue, and on diffusing into adjacent intact tissue cells stimulates them to divide. Traumatic acid has been isolated from the pods of green beans. 

Prohibit the advertisement, supply, storage and use of pesticides unless they have been approved. Pesticides includes herbicides, fungicides, wood preservatives, plant growth hormones, soil stenlants, bird or animal repellants. 

C03-0105. The line stmctures of three different plant growth hormones are given below. For each one, write the chemical formula for the compound and calculate its molar mass. 

Scheme 1. Molecular structure of the plant growth hormone auxin (indoleacetic acid, IAA). Extremely small amounts (nanomolar) can be detected by the auxin standard test 5 mm long segments of pea shoots elongate faster in the presence of exogenous auxin, which can be taken as a sensitive assay...

Phytoferritin transcription is induced by iron excess and repressed by iron deficiency in leaves as well as in roots in several plant species in the case of maize, there are two ferritin genes which are differentially regulated by two independent-signalling pathways, one involving an oxidative step and one dependent on the plant growth hormone, abscissic acid. 

Abscisic acid/plant growth hormone regulator that triggers abscission and closing of stomata... 

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. 

Important indole derivatives (see Scheme 2) include (i) indigo, a vat dye known and widely used since antiquity, and originally obtained from indican, a (3-glucoside of indoxyl which occurs in some plants. Indigo is now prepared synthetically. Tyrian purple, a natural dye used since classical times, is 6,6 -dibromoindigo (ii) the numerous indole alkaloids, with complex derivatives such as yohimbine and strychnine (iii) tryptophan, an essential amino acid found in most proteins. Its metabolites include skatole and tryptamine and (iv) 3-indoleacetic acid, which is important as a plant growth hormone. 

These compounds were originally isolated from a parasitic fungus that causes excessive leaf elongation in nee plants. The mechanisms and applications of this group of compounds are described in Gibberellic Acid and Gibberellin Plant Growth Hormones. 

PLANT HORMONES (Gibberellins). See Gibberellic Acid and Gibberellin Plant Growth Hormones. 

Auxin. A plant growth hormone usually concentrated in the apical bud. 

The study of the fungal gibberellins has had a very important consequence—the 1 discovery that the gibberellins are native plant growth hormones. 

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