Kinetin and gibberellic acid

The related substance xanthoxin (4.88) clearly plays a fundamental part in normal plant regulation by antagonizing indolylacetic acid, gibberellic acid, and kinetin. It is readily oxidized to abscisic acid, of which it is probably the natural precursor and with which it shares the trans,trans configuration (Taylor and Burden, 1972). 

Barea JM, Navarro E, Palomares A, Montoya E (1974) A rapid microbiological assay method for auxins, gibberellic acid and kinetin using yeast. J Appl Bacteriol 37 171-174... 

II. Long term effects of colchicine and lAA. New Phytol 65 532-546 Malik CP, Mehan M (1975 a) Correlative effects of auxin, gibberellic acid and kinetin on the elongation of pollen tubes in Calotropis procera. Biochem Physiol Pflanz 167 295-300... 

There is, however, another possibility. We have discussed that in all probability histones are repressors of genetic activity in higher organisms. Now Fellenberg has demonstrated that positive phytohormones, lAA, gibberellic acid, and kinetin, loosen the binding between histones and DNA. If the histone repressors were removed from DNA in this manner transcription could begin on the DNA now exposed. 

Mondal MH (1975) Effects of gibberellic acid, calcium, kinetin, and ethylene on growth and cell wall composition of pea epicotyls. Plant Physiol 56 622-625 Morgan PW, Gausman HW (1966) Effects of ethylene on auxin transport. Plant Physiol 41 45-52... 

Gibberellic acid promoted abscission at all concentrations, possibly by acceleration of protein hydrolysis and polysaccharide hydrolysis kinetin... 

Secondary metabolites, produced by pathways derived from primary metabolic routes, are numerous and widespread, especially in higher plants. More than 20,000 were known in 1985 (Hartmann, 1985), and at least 1000 additional compounds, are described each year. In practice, the difference between the primary and secondary metabolites is fuzzy. Plant hormones such as gibberellic acid, indoleace-tic acid (auxin), ethylene, kinetin, and abscisic acid, as well as compounds involved in plant cell wall structure such as cinnamic acid and its polymeric derivative, lignin, are intermediate between primary and secondary metabolism (Birch, 1973). In some instances, compounds normally considered primary metabolites may accumulate in large amounts and behave in a manner usually associated with secondary metabolites. Entities such as shikimic acid and squalene, which initially were considered secondary metabolites, were subsequently shown to be important intermediates in the formation of primary metabolites (phenylalanine, tyrosine and tryptophan, and steroids, respectively). 

Recently, the isolation of gibberellin and kinin provided further proof for the coumarin-auxin relation. These substances are included among the plant hormones, although gibberellic acid, a representative of gibberellins, was first isolated as a fungal metabolite, and kinetin, the best known kinin derivative was produced from nucleic acids [119-121]. Both of these compounds, however, were also found in higher plants. 

Winter A (1966) A hypothetical route for the biogenesis of lAA. Planta 71 229-239 Wright STC (1961) A sequential growth response to gibberellic acid, kinetin, and indolyl-acetic acid in the wheat coleoptile. Nature 190 699-700 Zimmerman DC, Coudron CA (1979) Identification of traumatin, a wound hormone, as 12-oxo-trans-lO-dodecanoic acid. Plant Physiol 63 536-541... 

Banerji D, Laloraya MM (1966) Comparative effects of indole-3-acetic acid, kinetin and gibberellic acid on the growth of isolated Cucurbita pepo cotyledons. Curr Sci 35 601-602... 

Bowen MR, Hoad GV (1968) Inhibitor content of phloem and xylem sap obtained from willow Salix viminalis) entering dormancy. Planta 81 64-70 Bowen MR, Wareing PF (1969) The interchange of " C-kinetin and " C-gibberellic acid between the bark and xylem of willow. Planta 89 108-125 Bowen MR, Wilkins MB, Cane AR, McCorquodale I (1972) Auxin transport in roots. VIII. The distribution of radioactivity in the tissues of Zea root segments. Planta 105 273-292... 

Davenport TL, Morgan PW, Jordan WR (1977 b) Auxin transport as related to leaf abscission during water stress in cotton. Plant Physiol 59 554-557 Davenport TL, Jordan WR, Morgan PW (1979) Movement of kinetin and gibberellic acid in leaf petioles during water stress-induced abscission in cotton. Plant Physiol 63 152-155... 

Sorokin HP, Mathur SN, Thimann KV (1962) The effects of auxins and kinetin on xylem differentiation in the pea epicotyl. Am J Bot 49 444-453 Stant MY (1961) The effect of gibberellic acid on fibre-cell length. Ann Bot 25 453-462 Stant MY (1963) The effect of gibberellic acid on cell width and the cell wall of some phloem fibers. Ann Bot 27 185-196... 

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