A new method for abscisic acid extraction and purification was developed to handle large numbers of small (about 125 milligrams fresh weight) samples of leaf discs. This method enabled short term changes in abscisic acid to be followed in single leaves.Water potentials, stomatal diffusion resistance, and abscisic acid levels were measured in the leaves of maize (Zea mays L. var. Wisconsin 575) ...

The effect of abscisic acid on growth, respiration, the ATP pool, and rate and amount of RNA synthesis in aseptically cultured axes of Phaseolus vulgaris during the first 24 hours of germination has been measured in experiments where the duration of abscisic acid application and its concentration have been varied. At concentrations from 10(-7) to 10(-4)m, abscisic acid inhibits synthesis of RNA...

The enzymatic conversion of xanthoxin to abscisic acid by cell-free extracts of Phaseolus vulgaris L. leaves has been found to be a two-step reaction catalyzed by two different enzymes. Xanthoxin was first converted to abscisic aldehyde followed by conversion of the latter to abscisic acid. The enzyme activity catalyzing the synthesis of abscisic aldehyde from xanthoxin (xanthoxin oxidase) was ...

This study compared the shelf life and quality of potted hydrangea (‘Speedy Red’) treated with different abscisic acid (ABA) spray concentrations investigated associated physiological changes. Plants were 0 (control), 1,000, 2,000, or 2,500 mg·L-1 ABA, which was applied by spraying. Treatment 2,000 ABA extended 2 days to control, treatment attenuated change in sepal color wilting other treatmen...

The objective of this work was to assess the regulatory effects of auxin‐priming on gas exchange and hormonal homeostasis in spring wheat subjected to saline conditions. Seeds of MH‐97 (salt‐intolerant) and Inqlab‐91 (salt‐tolerant) cultivars were subjected to 11 priming treatments (three hormones x three concentrations + two controls) and evaluated under saline (15 dS m‐1) and nonsaline (2.84 ...

Discussion The evidence presented here and previously (Neill et al., 1982a,b) strongly suggests that 1 ‘-deoxyabscisic acid (111) is the immediate precursor of abscisic acid in C. rosicola. Feeding studies have shown that 2-cis-a-ionylidene ethanol (I) and 2-cis-a-ionylidene acetic acid (11) are converted in good yield into 111 and abscisic acid. Thus they can be utilized as biosynthetic precur...

High salinity results in a decrease plant photosynthesis and crop productivity. The aim of the present study was to evaluate effect UV-C priming treatments lettuce seeds on plants grown at high salinity. Non-primed primed were an hydroponic system, with standard nutrient solution, either supplemented 100 mM NaCl (high salinity), or not (control). Considering that leaf root K + concentrations re...

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 3-fold. This rise in the level of abscisic acid took place during the 1st long da...

Gibberellic acid-induced alpha-amylase synthesis in barley (Hordeum vulgare L.) aleurone layers was inhibited by abscisic acid, and the inhibition was partly removed by additional gibberellic acid alone and by ethylene alone. Together additional gibberellic acid and ethylene almost eliminated abscisic acid inhibition of amylase synthesis. Time course studies of these phenomena showed that the e...

The plant hormones gibberellin and abscisic acid regulate gene expression, secretion and cell death in aleurone. The emerging picture is of gibberellin perception at the plasma membrane whereas abscisic acid acts at both the plasma membrane and in the cytoplasm - although gibberellin and abscisic acid receptors have yet to be identified. A range of downstream-signalling components and events ha...