The plasma membrane H(+)-ATPase (PM-H(+)-ATPase) of barley (Hordeum vulgare L. cv Klondike) roots was assayed by cross-reaction on western blots and cryosections with an antibody against the PM-H(+)-ATPase from corn roots. Under conditions of reduced K availability, which have previously been shown to increase K influx by greater than 25-fold, there were only minor changes detected in PM-H(+)-A...

Globally, over one-third of irrigated land is affected by salinity, including much of the land under lowland rice cultivation in the tropics, seriously compromising yields of this most important of crop species. However, there remains an insufficient understanding of the cellular basis of salt tolerance in rice. Here, three methods of 24Na+ tracer analysis were used to investigate primary Na+ t...

Studies are described that sought the basis for a discrepancy in values for a key kinetic parameter of methotrexate transport (influx Vn,»,( in LI 210 cells derived alternately from biochemical or pharmacokinetic measurements. Our results show that, within a short period of time following administration of a therapeutic dose of methotrexate to leukemic mice, influx of this folate analogue meas...

Corticosterone may nongenomically affect cell functions in addition to its well-characterized effects on gene expression. The purpose of this study is to examine if corticosterone has a rapid nongenomic effect on excitability of dorsal root ganglion neurons by using patch-clamp and single-cell Ca(2+) microfluometry techniques. The results show that corticosterone has a dose-dependent rapid inhi...

Sedum alfredii (Crasulaceae) is the only known Cd-hyperaccumulating species that are not in the Brassica family; the mechanism of Cd hyperaccumulation in this plant is, however, little understood. Here, a combination of radioactive techniques, metabolic inhibitors, and fluorescence imaging was used to contrast Cd uptake and translocation between a hyperaccumulating ecotype (HE) and a non-hypera...

ATP binding cassette (ABC) transporters transport diverse substrates across membranes in various organisms. However, plant ABC transporters have only been scantily characterized. By taking advantage of the auxin-sensitive Arabidopsis thaliana root hair cell and tobacco (Nicotiana tabacum) suspension cell systems, we show here that Arabidopsis P-glycoprotein4 (PGP4) displays auxin efflux activit...

The absorption of NO(3) (-) was characterized in six regions of a 7-d-old corn root (Zea mays L. cv W64A x W182E) growing in a complete nutrient solution. Based on changing rates of (15)N accumulation during 15-min time courses, translocation of the concurrently absorbed N through each region of the intact root was calculated and distinguished from direct absorption from the medium. Of the (15)...

“A`−1” stands for the A`−1 root system that underlies this model. Similarly, an elliptic Calogero-Moser system can be defined for each irreducible (but not necessary reduced) root system. Furthermore, for non-simply laced root systems, a kind of variants called “twisted model” and “extended twisted models” are also known. Those elliptic Calogero-Moser systems are known to possess an isospectral...

Analysis of small dorsal root ganglion (DRG) neurons revealed novel functions for vanilloid receptor 1 (VR1) in the regulation of cytosolic Ca(2+). The VR1 agonist capsaicin induced Ca(2+) mobilization from intracellular stores in the absence of extracellular Ca(2+), and this release was inhibited by the VR1 antagonist capsazepine but was unaffected by the phospholipase C inhibitor xestospongin...

Estimating functions can have multiple roots. In such cases, the statistician must choose among the roots to estimate the parameter. Standard asymptotic theory shows that in a wide variety of cases, there exists a unique consistent root, and that this root will lie asymptotically close to other consistent (possibly inefficient) estimators for the parameter. For this reason, attention has largel...