Gibberellic acid

About: Gibberellic acid is a research topic. Over the lifetime, 6597 publications have been published within this topic receiving 109294 citations. The topic is also known as: GIBBERELLIN A3.

Phytohormones (Auxin, Gibberellin) and ACC Deaminase In Vitro Synthesized by the Mycoparasitic Trichoderma DEMTkZ3A0 Strain and Changes in the Level of Auxin and Plant Resistance Markers in Wheat Seedlings Inoculated with this Strain Conidia

Abstract: Both hormonal balance and plant growth may be shaped by microorganisms synthesizing phytohormones, regulating its synthesis in the plant and inducing plant resistance by releasing elicitors from cell walls (CW) by degrading enzymes (CWDE). It was shown that the Trichoderma DEMTkZ3A0 strain, isolated from a healthy rye rhizosphere, colonized the rhizoplane of wheat seedlings and root border cells (RBC) and caused approximately 40% increase of stem weight. The strain inhibited (in over 90%) the growth of polyphagous Fusarium spp. (F. culmorum, F. oxysporum, F. graminearum) phytopathogens through a mechanism of mycoparasitism. Chitinolytic and glucanolytic activity, strongly stimulated by CW of F. culmorum in the DEMTkZ3A0 liquid culture, is most likely responsible for the lysis of hyphae and macroconidia of phytopathogenic Fusarium spp. as well as the release of plant resistance elicitors. In DEMTkZ3A0 inoculated plants, an increase in the activity of the six tested plant resistance markers and a decrease in the concentration of indoleacetic acid (IAA) auxin were noted. IAA and gibberellic acid (GA) but also the 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase (ACCD) enzyme regulating ethylene production by plant were synthesized by DEMTkZ3A0 in the liquid culture. IAA synthesis was dependent on tryptophan and negatively correlated with temperature, whereas GA synthesis was positively correlated with the biomass and temperature.

A Sequential Growth Response to Gibberellic Acid, Kinetin and Indolyl-3-Acetic Acid in the Wheat Coleoptile (TRITICUM VULGARE L.)

Abstract: A Sequential Growth Response to Gibberellic Acid, Kinetin and Indolyl-3-Acetic Acid in the Wheat Coleoptile (TRITICUM VULGARE L.)

Salicylic Acid Ameliorates Germination, Seedling Growth, Phytohormone and Enzymes Activity in Bean (Phaseolus vulgaris L.) under Cold Stress

Abstract: An experiment was carried out under laboratory condition to tackle low temperature stress by using salicylic acid (SA). Seeds of six common bean varieties (Polista, Nebraska, Goro, Helda, Duel and Giza 6) were soaked in water or 10 −4 M aerated solution of salicylic acid (SA) for 6 h. Treated and untreated seeds were germinated at 25 ○ C (optimal temperature) and at 15 ○ C (suboptimal temperature or chilling stress) under dark controlled conditions for 9 and 30 days , respectively. Germination and seedling growth of the six tested varieties were significantly hindered under low temperature. Seed treatments with SA significantly improved germination percentage, germination rate and seedling criteria, compared with control seeds under optimal and low temperature stress conditions. The content of Indolacetic acid (IAA), Gibberellic acid (GA3) and Abscisic acid (ABA) increased in the different varieties under study, in response to seed soaking in 10 −4 M SA at 15°C. GA3/ABA ratio showed maximum increase in Duel and Helda, while the lowest ratio was observed in Giza 6 and Nebraska seedlings. At the same low temperature, catalase activity was decreased, whereas that of polyphenol oxidase increased on using 10 -4 M SA. Peroxidase isozymes indicated five to three isozymes in seedlings of the six bean varieties. Salicylic acid treatment resulted in detecting (in Duel) and disappearance (in Nebraska) of peroxidase isozymes at Rf: 0.37, which might be responsible for tolerance and sensitivity mechanism, respectively. The present results indicated that, salicylic acid stimulated various growth aspects of bean seedlings perhaps through interference with the enzymatic activities responsible for biosynthesis and/or catabolism of growth promoting and inhibiting substances. Thus, it might be concluded that, SA could eliminate the adverse effects of cold stress in common bean. (Journal of American Science 2010;6(10):675-683). (ISSN: 1545-1003).

Mode of action of abscisic Acid in barley aleurone layers : induction of new proteins by abscisic Acid.

Abstract: As part of a continuing effort to elucidate the mode of action of abscisic acid (ABA) in barley (Hordeum vulgare L. cv Himalaya) aleurone layers, we have investigated the induction of several polypeptides by ABA in this tissue. There were nine ABA-induced polypeptides as observed by one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and considerably more (at least 16 spots) on a two-dimensional gel. These proteins started to show enhanced synthesis 2 to 4 hours after ABA treatment, and their synthesis continued for at least 48 hours. In vitro translation using total RNA isolated from ABA-treated aleurone layers indicated that translatable mRNA levels of these proteins essentially paralleled the levels of in vivo synthesized proteins. The most abundant of the ABA-induced proteins was a 29 kilodalton polypeptide which was also synthesized in tissue incubated without ABA. In vivo synthesis of this protein declined as ABA concentration was decreased, with 1 nanomolar ABA approaching control level. Cell fractionation experiments located the 29 kilodalton major ABA-induced protein in 1,000g and 13,000g pellets; most other induced proteins were in the 80,000g supernatant. The 29 kilodalton protein appeared to be sensitive to degradation by sulfhydryl type proteases. As expected, the induction of these proteins by ABA was suppressed by gibberellic acid. Phaseic acid, the first stable metabolite of ABA, suppressed the gibberellic acid-enhanced α-amylase synthesis but was unable to induce the ABA-induced proteins. None of the ABA-induced proteins were secreted into the incubation medium. A 36 kilodalton ABA-induced protein showed cross-reactivity with antibody against a barley lectin specific for glucosamine, galactosamine, and mannosamine.