Plant growth regulators, including auxin, gibberellin, cytokinin, abscisic acid, and ethylene, are investigated in this learning activity to demonstrate how these chemicals (hormones) affect plant growth and development.

Phytohormones, including auxins, abscisic acid, brassinosteroids, cytokinins, ethylene, gibberellins, and jasmonates, are involved in all aspects of plant growth, and developmental processes as well as environmental responses. However, our understanding of hormonal homeostasis is far from complete. Phytohormone conjugation is ...

Seed dormancy, afterripening, and germination are complex developmental process regulated by phytohormones. The phytohormone abscisic acid (ABA) is needed to set up seed dormancy during embryo maturation whereas gibberellin (GA) stimulates seed germination. In tomato and Arabidopsis, GA is clearly ...

Since the 14th Conference in Amsterdam in 1991, progress in plant hormone research and developmental plant biology has been truly astonishing. The five ''classical'' plant hormones, auxin, gibberellin, cytokinin, ethylene, and abscisic acid, have been joi...

Making an appropriate decision to germinate is essential for the survival of plant species and is important for proper stand establishment in crop plants. Germination is regulated by the antagonistic effects to two plant hormones in Arabidopsis thaliana: abscisic acid (ABA) induces dormancy and repr...

An inhibitor extracted from short day treated Acer negundo leaves was compared to abscisic acid in 4 different solvent systems. The chromatographic properties of abscisic acid and the inhibitor were in very close agreement. Treatment of Acer negundo plants under non-hardening preconditions (long days) with either ...

An inhibitor extracted from short day treated Acer negundo leaves was compared to abscisic acid in 4 different solvent systems. The chromatographic properties of abscisic acid and the inhibitor were in very close agreement. Treatment of Acer negundo plants under non-hardening preconditions (long days) with either ...

The interrelationship between water deficiency and hormonal makeup in plants was investigated in detached leaves of romaine lettuce (Lactuca sativa L. cv. `Hazera Yellow'). Water stress was imposed by desiccating the leaves for several hours in light or darkness at different air temperatures and relative humidity. In the course of desiccation, a rise in abscisic ...

Levels of (+)-abscisic acid present in the long-day plant spinach (Spinacia oleracea L., cv. Savoy Hybrid 612) grown under different photoperiodic regimes were measured in purified extracts by optical rotary dispersion. When plants were transferred from short to long days, the abscisic acid content increased 2- to ...

Barley germination is a complex and multi-stage biological process important to plant development, plant evolution, and agricultural production. It is accompanied with concerted expression of many genes and biological pathways. Transcriptomic analysis of barley grains/seedlings representing six well...

Seed dormancy is a common phase of the plant life cycle and several parts of the seed can contribute to dormancy. Whole seeds, seeds lacking the testa, embryos, and isolated aleurone layers of Arabidopsis thaliana were used in experiments designed to identify components of the arabidopsis seed that ...

17th International Conference on Arabidopsis Research, June 28-July 2, 2006, Madison, WI. Abstract #378. Seed germination is a complex developmental process regulated by phytohormones. The phytohormone abscisic acid (ABA) inhibits seed germination, whereas gibberellin (GA) stimulates seed germinat...

Seed germination is a complex developmental process regulated by phytohormones. The phytohormone abscisic acid (ABA) inhibits seed germination, whereas gibberellin (GA) stimulates seed germination. In tomato and Arabidopsis, GA is clearly required for seed germination. Recent evidence suggests tha...

Hormones which inhibit senescence in Rumex leaf tissue in the dark include gibberellic acid and the cytokinin zeatin. Abscisic acid accelerates senescence in this tissue. Other workers have proposed that cytokinins, but not gibberellins, interact with abscisic acid in ...

The authors cloned a cDNA for a gibberellin-induced ribonuclease (RNase) expressed in barley (Hordeum vulgare) aleurone and the gene for a second barley RNase expressed in leaf tissue. The protein encoded by the cDNA is unique among RNases described to date in that it contains a novel 23-amino acid insert between the C2 and C3 conserved sequences. ...

We cloned a cDNA for a gibberellin-induced ribonuclease (RNase) expressed in barley (Hordeum vulgare) aleurone and the gene for a second barley RNase expressed in leaf tissue. The protein encoded by the cDNA is unique among RNases described to date in that it contains a novel 23-amino acid insert between the C2 and C3 conserved sequences. Expression ...

... Accession Number : AD0854129. Title : Abscission: Role of Abscisic Acid. ... Abstract : The effect of abscisic acid on cotton (Gossypium hirsutum L. cv. ...

Hormones which inhibit senescence of Rumex leaf tissue in the dark include gibberellin A₃, and the cytokinins 6-benzylamino purine and zeatin. These hormones inhibit respiratory metabolism in this tissue, but do not change the pattern or total amount of oxygen consumption during senescence. Abscisic acid, a ...

Gibberellin A₁ (GA₁), 3-epi-GA₁, GA₄, GA₉, 11?-hydroxyGA₁₂, 12?-hydroxyGA₁₂, GA₁₅, GA₁₇, GA₁₉, GA₂₀, ...

Protein synthesis in gibberellin-treated lettuce (Lactuca sativa) seeds has been studied during the lag phase between the beginning of imbibition and the first signs of radicle protrusion. When compared to the water-imbibed controls, both polyribosome populations and radioactive leucine incorporation into protein increase in the embryos of GA/sub 3/-induced seeds early in the ...

We have used a transient expression assay in aleurone protoplasts of barley to delineate hormone response elements of the abscisic acid (ABA)-responsive rice gene Rab16A and of the gibberellin A3 (GA3)-responsive barley alpha-amylase gene Amy 1/6-4. Our approach used transcriptional fusions between their 5' upstream sequences and a ...

We have used a transient expression assay in aleurone protoplasts of barley to delineate hormone response elements of the abscisic acid (ABA)-responsive rice gene Rab16A and of the gibberellin A3 (GA3)-responsive barley alpha-amylase gene Amy 1/6-4. Our approach used transcriptional fusions between their 5' upstream sequences and a ...

Seedlings of castor bean (Ricinus communis cv. Hale) were exposed to a range of concentrations of gibberellin A₃ (GA₃). Treatments for 20 hours with GA₃ concentrations of 0.5 ?M or higher resulted in increased levels of NADH-cytochrome c reductase, phosphorylcholine glyceride transferase, and malate synthase ...