The plant hormone abscisic acid (ABA) plays a role in several aspects of plant growth and development. Understanding how this hormonal stimulus is sensed and transduced turned out to be one of the major tasks in the field of plant signaling. A series of recent papers proposed several different proteins that could receive the ABA signal and initiate the signaling cascade. The winner appears to b...

The question of whether abscisic acid (ABA) acts as an inhibitor or promoter of shoot growth in plants growing in drying soil is examined, drawing on current understanding of the role of ABA in root growth maintenance. Particular consideration is given to studies of endogenous ABA deficiency, which have shown that an important role of ABA is to limit ethylene production, and that this interacti...

The effect of abscisic acid (ABA) and excess benzyladenine (BA) on the formation of shoot from tea (Camellia sinensis L. assamica × sinensis) leaf was investigated in this research. Callus was formed and grew well when explants were cultured on LS basal medium supplemented with (in mg/L) thiamine-HCl, 1.25; pyridoxine-HCl, 0.625; nicotinic acid, 0.625; indole-3-acetic acid (IAA), 30; naphthalen...

Protein kinases are involved in signal transduction for environmental stress responses. In response to drought and salinity, a 48-kDa protein kinase (AAPK; abscisic acid-activated protein kinase (AAPK) in guard cells is activated by abscisic acid (ABA) and phosphorylates several targets such as the carboxy-terminus of inward-rectifying K+ channel and heterogeneous mRNA binding protein to adopt ...

The search for receptors for abscisic acid (ABA), a phytohormone central to the response of plants to biotic and abiotic stress, has been controversial. In this issue, Pandey et al. (2009) report the identification of two membrane proteins from Arabidopsis, GTG1 and GTG2, that bind ABA in vitro and mediate ABA responses in vivo.

Abscisic acid (ABA) levels were measured by enzyme-linked immunosorbent assay in developing zygotic embryos of Theobroma cacao. ABA was detected in all embryos tested, with a peak of ABA at levels of 1 to 3 micrograms per gram fresh weight during early maturation. This corresponded to embryos of 10 to 30% dry weight and to early stages of anthocyanin and lipid accumulation.

Abiotic stresses affect plant growth and development by causing cellular damage and/or restricting resources. Plants often respond to through abscisic acid (ABA) signaling. Exogenous ABA application can therefore be used mimic stress responses, which overridden glucose (Glc) addition during seed germination. It remains unclear whether ABA-mediated germination inhibition is due regional or globa...

Abscisic acid (ABA) is a key plant hormone involved in diverse physiological and developmental processes, including abiotic stress responses and the regulation of stomatal aperture and seed germination. Abscisic acid glucosyl ester (ABA-GE) is a hydrolyzable ABA conjugate that accumulates in the vacuole and presumably also in the endoplasmic reticulum. Deconjugation of ABA-GE by the endoplasmic...

The HPLC-MS/MS method was developed to profile the dynamics of abscisic acid (ABA) and ABA-glucose ester (ABA-GE) after cloning glycosyltransferase enzyme family gene AtUGT71C5 into Arabidopsis thaliana. By constructing over-expression lines (OE) and down-expression lines (DN), we acquired mutant strains to analyze the function of AtUGT71C5. The multiple-reaction monitoring (MRM) was used for q...

Structurally similar to retinoic acid (RA), the phytohormone abscisic acid (ABA) controls many developmental and physiological processes via complicated signaling networks that are composed of receptors, secondary messengers, protein kinase/phosphatase cascades, transcription factors, and chromatin-remodeling factors. In addition, ABA signaling is further modulated by mRNA maturation and stabil...