To elucidate the involvement of gibberellin (GA) in the growth regulation of Arabidopsis roots, effects of shoot-applied GA and GA-biosynthesis inhibitors on the root were examined. Applying GA to the shoot of Arabidopsis slightly enhanced the primary root elongation. Treating shoots with uniconazole, a GA biosynthesis inhibitor, also resulted in enhancement of primary root elongation, while sh...

Suspension cultures were incubated in the presence and absence of gibberellic acid (GA(3)) in an attempt to define a new experimental system for study of the molecular action of gibberellins upon growth. Unlike many suspension cultures, an auxin-independent green clone from spinach (Spinacia oleracea L.) and an auxin-dependent line of "Paul's Scarlet" rose (Rosa sp.) were promoted in expansion ...

Recent studies using biochemical and genetic approaches have identified a number of components, including several negative regulators, of the gibberellin (GA) signal transduction pathway in higher plants. The basal state of GA signaling is likely to be repressive, and the GA signal seems to activate the pathway by de-repression to allow GA-stimulated growth and development.

Recent molecular biological and genetical studies have identified several positive and negative regulators of gibberellin (GA) signalling pathways in higher plants. The DELLA protein functions as a negative regulator of GA signalling; its degradation through the ubiquitin/proteasome pathway is a key event in the regulation of GA-stimulated processes.

Bioactive gibberellins (GAs) are plant hormones that control growth and development throughout the life cycle of the plant. Isolation and characterization of mutants that are impaired in GA biosynthesis have been crucial in both understanding the role of GAs in regulating plant development and elucidating the GA biosynthetic pathway (Davies, 1995; Hedden and Phillips, 2000). The broad spectrum ...

Presoaking several varieties of seed, especially lettuce, in various 6(substituted) aminoand thiopurine solutions has been found to increase their rate of germination (3, 5, 6). Recently it was also reported that these purine derivatives are synergistic with gibberellin in inducing these biological responses whereas gibberellin alone was only moderately active in stimulating germination of Earl...

Summer annuals overwinter as seeds in the soil seed bank. This is facilitated by a cold-induced increase in dormancy during seed maturation followed by a switch to a state during seed imbibition in which cold instead promotes germination. Here, we show that the seed maturation transcriptome in Arabidopsis thaliana is highly temperature sensitive and reveal that low temperature during seed matur...

Sum,itmary. Barley embryos, completely free from endospernm, wvere excised from germinating grain at various times and al'lowed to diffuse into an aqueous medium for varying lengths of time. At the end of this time, the embrvos and ambient solutioins were separately extracted. Gibberellin-like activity in the extracts was determined with the barley endosperm bioassay using seed from the same va...

Gibberellins are a large family of tetracyclic diterpenoid plant hormones that induce a wide range of plant growth responses including seed germination, stem elongation, leaf expansion, pollen maturation and induction of flowering. Gibberellins were first discovered by a Japanese plant pathologist, Eiichi Kurosawa, from the pathogenic fungus Gibberella fujikuroi in 1926 [1]. Kurosawa was workin...

Abstract The objective of this work was to validate the enzymatic activity in Annona x atemoyaseeds submitted treatments with plant growth regulators belonging group gibberellins and cytokinins for overcoming dormancy during germination process. Initially, water acquisition curve determined, where two points phase II (72 144 hours) were determined evaluate superoxide dismutase (SOD), peroxidase...