Potassium extrusion by plant cells: evolution from an emergency valve to a driver of long-distance transport.

The ability to accumulate nutrients is a hallmark for living creatures and plants evolved highly effective nutrient transport systems, especially for the uptake of potassium (K). However, plants also developed mechanisms that enable the rapid extrusion of K in combination with anions. The combined release of K and anions is probably an ancient extrusion system, as it is found in the Characeae that are closely related to land plants.

The outward shaker channel OsK5.2 improves plant salt tolerance by contributing to control of both leaf transpiration and K secretion into xylem sap.

Soil salinity constitutes a major environmental constraint to crop production worldwide. Leaf K /Na homoeostasis, which involves regulation of transpiration, and thus of the xylem sap flow, and control of the ionic composition of the ascending sap, is a key determinant of plant salt tolerance. Here, we show, using a reverse genetics approach, that the outwardly rectifying K -selective channel OsK5.

Investigation of Na+ and K+ Transport in Halophytes: Functional Analysis of the HmHKT2;1 Transporter from Hordeum maritimum and Expression under Saline Conditions.

Control of K+ and Na+ transport plays a central role in plant adaptation to salinity. In the halophyte Hordeum maritimum, we have characterized a transporter gene, named HmHKT2;1, whose homolog HvHKT2;1 in cultivated barley, Hordeum vulgare, was known to give rise to increased salt tolerance when overexpressed. The encoded protein is strictly identical in two H.

Effect of salinity on osmotic adjustment, proline accumulation and possible role of ornithine-δ-aminotransferase in proline biosynthesis in .

The short time response to salt stress was studied in . Plants were exposed to different salt concentrations (0, 100, 200 and 400 mM NaCl) and harvested after 4, 24, 72 and 168 h of treatment. Before harvesting plants, tissue hydration, osmotic potential, inorganic and organic solute contents, and ornithine-δ-aminotransferase activity were measured.

Salt stress reveals differential physiological, biochemical and molecular responses in and wheat genotypes.

Salt stress responses implicate a complex mechanism and differ from plant species to another. In this study, we analyzed the physiological, biochemical and molecular responses to salt stress of the diploid wheat () and compared to the tetraploid wheat (). Our results showed that the diploid wheat cultivar (cv.