The effect of acclimation to drought in seedlings of Mediterranean evergreen sclerophyll Laurus nobilis L. (laurel) was studied in semiarid field conditions. The phytohormones abscisic acid (ABA), gibberellic acid (GA 3), zeatin (Z) and indole-3-acetic acid (IAA) contents, plant water potential, photochemical efficiency, and morphological characters were determined. Seedlings were acclimated to...

Autophagy has recently been shown to be required for postmeiotic anther development including anther dehiscence, programmed cell death-mediated degradation of the tapetum and pollen maturation in rice. Several phytohormones are known to play essential roles during male reproductive development including pollen maturation. However, the relationship between phytohormone metabolism and autophagy i...

Many plant developmental, physiological and metabolic processes are regulated, at least in part, by nutrient availability. In particular, alterations in the availability of soluble sugars, such as glucose and sucrose, help regulate a diverse array of processes. Multiple lines of evidence indicate that many of these processes are also regulated in response to other signalling molecules, such as ...

Cytokinins were discovered in the search for factors that promoted division of plant cells in culture. Naturally occurring cytokinins are N-substituted adenine derivatives that generally contain an isoprenoid derivative side chain. These hormones influence numerous aspects of plant development and physiology, including seed germination, de-etiolation, chloroplast differentiation, apical dominan...

Calcium-dependent protein kinases (CPKs/CDPKs) are Ca2+-sensors that decode Ca2+ signals into specific physiological responses. Research has reported that CDPKs constitute a large multigene family in various plant species, and play diverse roles in plant growth, development, and stress responses. Although numerous CDPKs have been exhaustively studied, and many of them have been found to be invo...

Low soil temperature is one of the reasons for poor germination and establishment of maize. The aim of this study was to evaluatethe possibilityof improvingthe seedling emergence and performance of maize under low temperature stress. A pot experiment was conducted on Zea maize (single cross 704) at 14 ºC as cold stress and seed treatments were priming with  200,  300 and 400ppm of GA3; 100, 200...

Environmental changes strongly affect plant growth and development. Phytohormones, endogenous plant-made small molecules such as ethylene, regulate a wide range of processes throughout the lifetime of plants. The ability of plants to integrate external signals with endogenous regulatory pathways is vital for their survival. Ethylene has been found to suppress hypocotyl elongation in darkness wh...

The sedimentaion of amyloplasts in tomato leaf petiole cells, when influenced by gravistimulation, gravistimulation and phytohormone epine, an exogenous source ethylene ethephon for a period 0.25–24 h, was demonstrated. Ethephone significantly slowed down the sedimentation serving as statolytes which correlates with its inhibitory effect on formation gravitropic bending stem.

We identify an Arabidopsis pyridoxal-phosphate-dependent aminotransferase, VAS1, whose loss-of-function simultaneously increases amounts of the phytohormone auxin and the ethylene precursor 1-aminocyclopropane-1-carboxylate. VAS1 uses the ethylene biosynthetic intermediate methionine as an amino donor and the auxin biosynthetic intermediate indole-3-pyruvic acid as an amino acceptor to produce ...

Bacteria have evolved gibberellin phytohormone biosynthesis independently of plants and fungi. Through 13C-labeling and NMR analysis, the mechanistically unusual "B" ring contraction catalyzed by a cytochrome P450 (CYP114), which is the committed step in gibberellin biosynthesis, was shown to occur via oxidative extrusion of carbon-7 from ent-kaurenoic acid in bacteria. This is identical to the...