Phytohormones are present in seaweeds but little is known about occurrence and content of them in seaweeds of Persian Gulf. The aim of this study was extraction of abscisic acid and gibberellin in Sargassum muticum and Gracilaria corticata. The seaweeds were collected bimonthly over one year at Bushehr coasts, Persian Gulf, during a range of environmental conditions. We explored new HPLC method...

The Arabidopsis hypocotyl, together with hormone mutants and chemical inhibitors, was used to study the role of auxin in cell elongation and its possible interactions with ethylene and gibberellin. When wild-type Arabidopsis seedlings were grown on media containing a range of auxin concentrations, hypocotyl growth was inhibited. However, when axr1-12 and 35S-iaaL (which have reduced auxin respo...

A single neonatal treatment of rats with vitamin D3, gibberellin, allylestrenol or diethylstilbestrol (DES) influenced the ouabain binding capacity of myocardial Na, K-dependent ATP-ase. Of the active molecules tested, vitamin D3, DES and gibberellin had appreciable impact on myocardial ouabain receptors, enhancing and depressing their activity, respectively. The thymic dexamethasone and uterin...

Two inhibitory fractions (B(1) and C) from extracts of immature fruit of carob were tested for their ability to inhibit the action of indoleacetic acid (IAA) in three bioassays. There was no reduction of IAA-induced reactions in the Avena curvature test, abscission of debladed coleus petioles, or growth of cucumber hypocotyls. The highest ratio of inhibitor to IAA was 10,000 times greater than ...

Potential sites of gibberellin biosynthesis in 10-day-old ;Alaska' pea (Pisum sativum L.) seedlings were investigated using a cell-free ezyme system capable of incorporating [(14)C]-mevalonic acid into ent-kaurene. In peas, ent-kaurene is assumed to be a committed intermediate in the gibberellin biosynthetic pathway. Comparative results from enzyme assays using extracts from shoot tips, leaf bl...

Peony plants require temperate winter temperatures to break underground bud dormancy and allow shoot emergence flowering in spring. This study assessed whether artificial chilling at 4 °C for 2–6 weeks could induce under subtropical conditions. It also pre-treatment cool prior chilling, or gibberellin application after promoted flowering. Artificial 6 the greatest emergence. Pre-treatment did n...

From a comparison of the effects of seven growth retardants and abscisic acid (ABA) on various growth systems, it was found that the gibberellin-regulated growth of lettuce hypocotyls was uniquely inhibited by the growth retardant, alpha-cyclopropyl-alpha-(4-methoxyphenyl)-5-pyrimidine methanol (EL-531). Auxin-regulated growth of coleoptile sections was inhibited by Phosfon and only slightly by...

Dwarf maize (Zea mays L.), a mutant deficient in gibberellin synthesis, provides an excellent model to study the influence of gibberellin on biochemical processes related to plant development. Alterations in the chemical structure of the cell wall mediated by gibberellin were examined in seedlings of this mutant. The composition of the walls of roots, mesocotyl, coleoptile, and primary leaves o...

Tissue culture provides a useful system to investigate how plant hormones are involved in this process. Auxin and cytokinin are widely used in plant regeneration. Gibberellin is also an important plant hormone in regulating plant growth and development. It is interesting to know the effects of gibberellin and its signalling pathway on plant regeneration. In this report Arabidopsis thaliana land...

Gibberellins are compounds that produce a wide variety of growth responses in flowering plants. Among these responses are stimulation of shoot growth for many plant species,' root elongation in maize,2 induction of bolting and flowering in some biennial and long-day plants,3-resumption of normal growth in certain genetically dwarfed genotypes of maize,6 growth stimulation in dwarf strains of pe...