Abscisic acid (ABA) is a vital cellular signal in plants, and effective ABA signalling is pivotal for stress tolerance. AtLOS5 encoding molybdenum cofactor sulphurase is a key regulator of ABA biosynthesis. Here, transgenic AtLOS5 plants were generated to explore the role of AtLOS5 in salt tolerance in maize. AtLOS5 overexpression significantly up-regulated the expression of ZmVp14-2, ZmAO, and...

PURPOSE To investigate the presence of calcium (Ca) aggregates influencing biocompatibility and the factors that affect calcium accumulation in explanted intraocular lenses (IOL) and to analyze the Ca distribution in an opacified hydrophilic acrylic lens. METHODS Surface irregularities and aggregates of 13 IOLs were studied with scanning electron microscopy, and their relative concentrations ...

The ability of aluminum to inhibit the (Na(+)/K(+))ATPase activity has been observed by several investigators. The (Na(+)/K(+))ATPase is characterized by a complex molecular heterogeneity that results from the expression and differential association of multiple isoforms of both catalytic (alpha) and regulatory (beta) subunits. For instance, three main alpha (alpha(1), alpha(2) and alpha(3)) and...

It is widely accepted that a critical factor in determining neuronal death during cerebral ischemia is the progressive accumulation of intracellular Na ([Na ]i) and Ca ([Ca ]i) ions, which can precipitate necrosis and apoptosis of vulnerable neurons. Whereas the detrimental action of [Na ]i increase is attributable to both cell swelling and microtubular disorganization—2 phenomena that lead to ...

The characteristics of hypoxanthine transport were examined in purified brush-border membrane vesicles isolated from guineapig kidney. Hypoxanthine uptake in the vesicles was specifically stimulated by both Na+ and an inside-negative potential, resulting in a transient accumulation of intravesicular hypoxanthine. Na+-dependent hypoxanthine influx was saturable (apparent Km 4.4 + 2.1 ,uM, Vmax 1...

Neurons have high densities of voltage-gated Na(+) channels that are restricted to axon initial segments and nodes of Ranvier, where they are responsible for initiating and propagating action potentials. New findings (Bréchet, A., M.-P. Fache, A. Brachet, G. Ferracci, A. Baude, M. Irondelle, S. Pereira, C. Leterrier, and B. Dargent. 2008. J. Cell Biol. 183:1101-1114) reveal that phosphorylation...

Schäfer, C., Y. V. Ladilov, M. Schäfer, and H. M. Piper. Inhibition of NHE protects reoxygenated cardiomyocytes independently of anoxic Ca overload and acidosis. Am J Physiol Heart Circ Physiol 279: H2143–H2150, 2000.—We investigated the question of whether inhibition of the Na/H exchanger (NHE) during ischemia is protective due to reduction of cytosolic Ca accumulation or enhanced acidosis in ...

Salinity stress is the most widespread and the most severe abiotic stress that plants face. More than 800 million hectares worldwide, representing more than 6% of world's land area, are affected by salinity. Tomato is one of the most important horticultural crops. However, due to the progressive salinization of irrigated land, areas for optimal growth of tomato are being reduced all over the wo...

Voltage-gated sodium (Na(v)) channels accumulate at the axon initial segment (IS), where their high density supports spike initiation. Maintenance of this high density of Na(v) channels involves a macromolecular complex that includes the cytoskeletal linker protein ankyrin-G, the only protein known to bind Na(v) channels and localize them at the IS. We found previously that Na(v)1.6 is the pred...

Two Zea mays cultivars, salt sensitive Trihybrid 321 and salt tolerant Giza 2, were studied, namely their adaptation to NaCl imposition at cell and whole plant level. Changes in growth and mineral content of roots and shoots, glycinebetaine (GB) and free proline (Pro) levels of shoots, plasma membrane permeability and solute potential (ø s) of leaf sheath subepider-mal cells were measured. NaCl...