To understand the role of small GTPases in response to abiotic stress, we isolated a gene encoding a small GTPase, designated MfARL1, from a subtracted cDNA library in Medicago falcata, a native legume species in semi-arid grassland in northern China. The function of MfARL1 in response to salt stress was studied by expressing MfARL1 in Arabidopsis. Wild-type (WT) and transgenic plants constitut...

Salinity-induced osmotic, ionic and oxidative stress responses were investigated on Asakaze/Manas wheat/barley addition lines 7H, 7HL and 7HS, together with their barley (salt-tolerant) and wheat (relatively salt-sensitive) parents. Growth, photosynthetic activity, chlorophyll degradation, proline, glycine betaine accumulation, sugar metabolism, Na+ and K+ uptake and transport processes and the...

Na+-K+-2Cl- cotransporter has been suggested to contribute to active intracellular Cl- accumulation in neurons at both early developmental and adult stages. In this report, we extensively characterized the Na+-K+-2Cl- cotransporter in primary culture of cortical neurons that were dissected from cerebral cortex of rat fetus at embryonic day 17. The Na+-K+-2Cl- cotransporter was expressed abundan...

1. Preparations ofmouse ascites-tumour cells depleted ofATP and Na+ ions accumulated L-methionine, in the presence of cyanide and deoxyglucose, from a 1mm solution containing 80mequiv. of Na+/1 and about 5mequiv. of K+/l. Valinomycin increased, from about 4 to 16, the maximum value of the ratio of the cellular to extracellular concentrations of methionine formed under these conditions without m...

Salinity is considered one of the major limiting factors for plant growth and agricultural productivity. We are using salt cress (Thellungiella halophila) to identify biochemical mechanisms that enable plants to grow in saline conditions. Under salt stress, the major site of Na+ accumulation occurred in old leaves, followed by young leaves and taproots, with the least accumulation occurring in ...

Single Nucleotide Polymorphisms (SNPs) within the coding sequence of HKT transporters are important for the functioning of these transporters in several plant species. To unravel the functioning of HKT transporters analysis of natural variation and multiple site-directed mutations studies are crucial. Also the in vivo functioning of HKT proteins, via complementation studies performed with athkt...

Melatonin (MT) is a multifunctional molecule in animals and plants and is involved in defense against salinity stress in various plant species. In this study, MT pretreatment was simultaneously applied to the roots and leaves of sweet potato seedlings [Ipomoea batatas (L.) Lam.], which is an important food and industry crop worldwide, followed by treatment of 150 mM NaCl. The roles of MT in med...

1. Formation of inositol phosphates (InsPs) was measured in cross-chopped slices or dispersed cells, isolated by collagenase treatment, of guinea-pig ileum longitudinal smooth muscle pre-labelled with [3H]inositol. 2. Elevation of the extracellular K+ concentration by equimolar replacement of Na+ induced accumulation of InsPs in the dispersed cells and in the tissue slices. These effects were b...

Slow conduction and unidirectional conduction block (UCB) are key mechanisms of reentry. Following abrupt changes in heart rate, dynamic changes of conduction velocity (CV) and structurally determined UCB may critically influence arrhythmogenesis. Using patterned cultures of neonatal rat ventricular myocytes grown on microelectrode arrays, we investigated the dynamics of CV in linear strands an...

Excised barley (Hordeum vulgare var Larker) leaves were treated with salt solutions or wilted. After the treatment period, the leaves were allowed to recover in a 50 millimolar sucrose and 1 millimolar glutamate solution, and proline, Na(+), and K(+) were measured at intervals. Na(+) and K(+) concentrations stayed at a constant high level after the salt treatments, and proline increased to a st...