Abscisic acid (ABA) is a key hormone regulating plant growth, development and the response to biotic and abiotic stress. ABA binding to pyrabactin resistance (PYR)/PYR1-like (PYL)/Regulatory Component of Abscisic acid Receptor (RCAR) intracellular receptors promotes the formation of stable complexes with certain protein phosphatases type 2C (PP2Cs), leading to the activation of ABA signalling. ...

Aluminum (Al)-induced decrease in leaf hydration has been associated with low gas exchange, especially stomatal conductance (gs). However, the mechanisms explaining these responses are unclear. Citrus limonia was exposed to 0 and 1480 μM Al nutrient solution for 90 days test whether gs plants is increased 9-cis-epoxycarotenoid dioxygenase (NCED) gene expression abscisic acid (ABA) biosynthesis....

The plant growth regulator abscisic acid (ABA) is formed by the oxidative cleavage of an epoxy-carotenoid. The synthesis of other apocarotenoids, such as vitamin A in animals, may occur by a similar mechanism. In ABA biosynthesis, oxidative cleavage is the first committed reaction and is believed to be the key regulatory step. A new ABA-deficient mutant of maize has been identified and the corr...

Changes in levels of abscisic acid (ABA) and cytokinin activity in the xylem sap of willow (Salix viminalis, L.) were followed throughout two growth cycles.Growth in spring was preceded by decreasing levels of ABA and an increase in cytokinin activity. The onset of dormancy was associated with low levels of cytokinins and high contents of ABA. A second peak of ABA was found in July which was no...

Isolated guard cells, prepared by sonication of epidermal peels, were used to investigate the endogenous level of abscisic acid (ABA) in the guard cells of turgid and stressed leaves of Vicia faba L. and the argenteum (arg) mutant of Pisum sativum L. The guard cells of V. faba and arg were found to contain 18 and 8 times more ABA, respectively, when isolated from stressed leaves than from turgi...

Abbreviations: 2,4-D: 2,4-dichlorophenoxyacetic acid ABA: abscisic acid ABI3: ABI gene family member 3 ANP1: Arabidopsis NPK1-like protein kinase AP: ascorbate peroxidase AOX: alternative oxidase DNA: deoxyribonucleic acid Fe-EDTA: ferric ethylenediaminetetraacetic acid M: molar concentration MAPK: mitogen-activated protein kinase NO: Nitric oxide PGRs: plant growth regulators ROS: reactive oxy...

Abscisic acid (ABA), auxins, cytokinins, gibberellic acid, alone or in combination were tested for their effects on short-term sucrose uptake in sugar beet (Beta vulgaris cv USH-20) roots. The effect of ABA on active sucrose uptake varied from no effect to the more generally observed 1.4-to 3.0-fold stimulation. A racemic mixture of ABA and its trans isomer were more stimulatory than ABA alone....

Fruit ripening and senescence are finely controlled by plant hormones such as ethylene abscisic acid (ABA) but also calcium ions calcium-dependent signaling pathways. Although there extensive data supporting an interaction between in fruit ripening, the regulatory mechanisms resulting from ABA have not yet been fully clarified. In this article, we reviewed full roles of its sensors (CaM, CMLs, ...

Fibrillins are lipid-binding proteins of plastids that are induced under abiotic stress conditions. In response to environmental stress, plants generate abscisic acid (ABA) as an endogenous signal. We show that ABA treatment and fibrillin accumulation enhance the tolerance of photosystem II toward light stress-triggered photoinhibition in Arabidopsis. ABA induces fibrillin accumulation, and the...

Microspore-derived embryos of Brassica napus cv Reston were used to examine the effects of exogenous (+)-abscisic acid (ABA) and related compounds on the accumulation of very-long-chain monounsaturated fatty acids (VLCMFAs), VLCMFA elongase complex activity, and induction of the 3-ketoacyl-coenzyme A synthase (KCS) gene encoding the condensing enzyme of the VLCMFA elongation system. Of the conc...