A fluorescence polarization immunoassay (FPIA) procedure is developed for the determination of 2,4-dichlorophenoxyacetic acid in cereal grains using a Sentry-200 portable device. We synthesized tracers, that is, antigens labeled with f luorescein derivatives, based on two fluorescent compounds and two chlorophenoxyacids. The tracer synthesized from 2,4-dichlorophenoxyacetic acid and 4-aminometh...

Although brassinosteroids (BRs) are known to regulate shoot growth, their role in the regulation of root growth is less clear. We show that low concentrations of BRs such as 24-epicastasterone and 24-epibrassinolide promote root elongation in Arabidopsis wild-type plants up to 50% and in BR-deficient mutants such as dwf1-6 (cbb1) and cbb3 (which is allelic to cpd) up to 150%. The growth-stimula...

D. C. Effect of 2,4-dichlorophenoxyacetic acid on respiration and on destruction of indoleacetic acid in oat and sunflower tissues. Science 120: 710-712. 1954. 9. HUMPHREYS, T. E. and DUGGER, W. M., JR. The effect of 2,4-dichlorophenoxyacetic acid on the respiration of etiolated pea seedlings. Plant Physiol. 31 Suppl.: xxii. 1956. 10. HUMPHREYS, T. E. and DUGGER, W. M., JR. The effect of 2,4-di...

Ethylene inhibits growth in the subhook region of intact etiolated pea seedlings (Pisum sativum, var. Alaska) by reducing the capacity of the polar auxin transport system supplying auxin to the tissue. Application of 0.1 mm 2,4-dichlorophenoxyacetic acid reverses the growth inhibition caused by ethylene, and stimulates formation of sufficient gas to induce a swelling response in the absence of ...

Release of divalent ions from membrane pellets of soybean hypocotyls was promoted by the natural auxin, indole-3-acetic acid, and the synthetic auxin, 2,4-dichlorophenoxyacetic acid. The calcium release occurred at auxin concentrations as low as 1 nanomolar, and maximum release was observed at 1 micromolar. Hormone concentrations greater than 1 micromolar showed reduced effectiveness in releasi...

This study investigated the toxic effects of 2,4-dichlorophenoxyacetic acid on male Sprague-Dawley rats. In which, 30 rats were divided into three even groups. First group received orally normal saline (3 ml/kg b.w.) and kept as normal control in parallel to treated groups (5 rats each), second group received orally 2,4-dichlorophenoxyacetic acid (30 mg/kg b.w.) for 2 months and third group rec...

2,4-Dichlorophenoxyacetic Acid, Glycine max L., Plant Cell Suspension Culture, Vacuole, /?-ü-Glucosides Cell suspension cultures of soybean (Glycine m ax L.) were incubated with [14C]-2,4dichlorophenoxyacetic acid (62 h, 27 °C). The cells were converted to protoplasts by use of the cell-wall degrading enzymes, Driselase and pectinase. This procedure resulted in the release of the cellular amino...

2,4-Dichlorophenoxyacetic acid had a multiple effect on the development of indoleacetic acid oxidase isoenzymes in tobacco callus tissues (Nicotiana tabacum, cv. White Gold) cultured in vitro, and the development of these isoenzymes was differentially associated with growth promotion or inhibition depending on the concentration of 2,4-dichlorophenoxyacetic acid. At low concentrations (0.1 to 1 ...

An investigation has been made of the RNA synthesized by chromatin-bound RNA polymerase from soybean hypocotyls (Glycine max var. Wayne). Polymerase activity is 4- to 5-fold higher with chromatin from tissue treated with 2,4-dichlorophenoxyacetic acid, a synthetic auxin, compared to untreated tissue. Thin layer chromatography of the RNA hydrolysis products and acrylamide gel electrophoresis of ...