Topic
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.
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TL;DR: It is shown that high carbohydrate levels in the maturation medium significantly increase plant conversion of oak somatic embryos, which exhibit no variation in DNA sequences when proliferated by secondary embryogenesis.
38 citations
TL;DR: It is suggested that GA(3) can reverse biochemical events of tuberization in tubers as well as prevent the accumulation of the major tuber proteins in other inducible tissues.
Abstract: Many studies have shown that gibberellic acid (GA3) inhibits tuberization in potato (Solanum tuberosum L.). In this study, we have utilized the 40 kilodalton glycoprotein, patatin, as a marker for biochemical events associated with the process of tuberization. To determine the effects of exogenous applications of GA3 on the induction of the accumulation of this major tuber protein, we measured patatin levels in tubers from treated whole plants, petioles from a single-node cutting system with GA3 applied in a lanolin paste, and stolon tips cultured in vitro on an inductive medium supplemented with GA3. In all three systems, GA3 inhibited the accumulation of patatin and the major 15 and 22 kilodalton tuber proteins. This effect appeared to be selective since most of the other proteins were not affected and, in tubers, at least one protein was stimulated by GA3. These results suggest that GA3 can reverse biochemical events of tuberization in tubers as well as prevent the accumulation of the major tuber proteins in other inducible tissues.
38 citations
TL;DR: In this article, the effect of cytokinin, kinetin, and Gibberellic acid on abscisic acid (dormin) inhibition of α-amylase synthesis and growth in intact barley seed was investigated.
Abstract: The effect of cytokinin, kinetin, on abscisic acid (dormin) inhibition of α-amylase synthesis and growth in intact barley seed was investigated. Abscisic acid at 5 × 10−5M nearly completely inhibited growth response and α-amylase synthesis in barley seed. Kinetin reversed to a large extent abscisic acid inhibition of α-aniylase synthesis and coleoptile growth. The response curves of α-amylase synthesis and coleoptile growth in presence of a fixed amount of abscisic acid (6 × l0−6M) and increasing concentrations of kinetin (from 5 × l0−7M to 5 × 10−5 M) showed remarkable similarity. Kinetin and abscisic acid caused synergistic inhibition of root growth. Gibberellic acid was far less effective than kinetin in reversing abscisic acid inhibition of α-amylase synthesis and coleoptile growth. A combination of kinetin and gibberellic acid caused nearly complete reversal of abscisic acid inhibition of α-amylase synthesis but not the abscisic acid inhibition of growth. The results suggest that factors controlling α-amylase synthesis may not have a dominant role in all growth responses of the seed. Kinetin possibly acts by removing the abscisic acid inhibition of enzyme specific sites thereby allowing gibberellic acid to function to produce α-amylase.
38 citations
TL;DR: It is suggested that SA might protect tomato fruit from CI and oxidative damage through regulating GA metabolism, CBF1 gene expression, and antioxidant enzyme activities.
Abstract: Effects of salicylic acid (SA) on gibberellin (GA) homeostasis, C-repeat/dehydration-responsive element binding factor (CBF) pathway, and antioxidant enzyme systems linked to chilling- and oxidative-stress tolerance in tomato fruit were investigated. Mature green tomatoes (Solanum lycopersicum L. cv. Moneymaker) were treated with 0, 0.5, and 1 mM SA solution for 15 min before storage at 4 °C for 28 days. In comparison to 0 or 0.5 mM SA, 1 mM SA significantly decreased the chilling injury (CI) index in tomato fruit. In the SA-treated fruit, the upregulation of GA biosynthetic gene (GA3ox1) expression was followed by gibberellic acid (GA3) surge and DELLA protein degradation. CBF1 participated in the SA-modulated tolerance and stimulated the expression of GA catabolic gene (GA2ox1). Furthermore, 1 mM SA enhanced activities of antioxidant enzymes and, thus, reduced reactive oxygen species accumulation. Our findings suggest that SA might protect tomato fruit from CI and oxidative damage through regulating GA ...
38 citations
01 Jan 2010
TL;DR: The effect of gibberellin on promoting stem growth was first discovered in 1930s by studies of the Bakanae(foolish seedling) disease in rice and analysis of their GA contents revealed that bioactive GAs are endogenous hormones that regulate the natural developmental processes including stem growth in plants.
Abstract: The effect of gibberellin (GA) on promoting stem growth was first discovered in 1930s by studies of the Bakanae(foolish seedling) disease in rice (57). Gibberella fujikuroi, a pathogenic fungus, produces gibberellic acid (GA3) that causes the infected rice plants to grow so tall that they fall over. Later studies of dwarf mutants and analysis of their GA contents revealed that bioactive GAs are endogenous hormones that regulate the natural developmental processes including stem growth in plants. An increase in both cell elongation and cell division occurs during stem growth. GA induces transcription of genes involved in these processes. For example, expression of some of the genes encoding xyloglucan endotransglycosylases (XETs1) and expansins are upregulated by GA in elongating internodes in rice and in Arabidopsis (7, 62, 66). XET is thought to increase the plasticity of the cell wall because this enzyme is involved in xyloglucan reorganization through cleaving and re-ligating xyloglucan polymers in the cell wall. Expansins are also extracellular proteins that cause plant cell wall loosening, probably by disrupting the polysaccharide adhesion. Transcripts of the genes encoding for cyclin-dependent protein kinases are also elevated in intercalary meristem in rice after GA treatment (12).
38 citations