Enhanced anti-malarial efficacy of mefloquine delivered via cationic liposome in a murine model of experimental cerebral malaria.

Malaria is a longstanding global health challenge that continues to afflict over 90 countries located in tropical and subtropical regions of the globe. The rise of drug-resistant malarial parasites has curtailed the therapeutic efficacy of a number of once-effective anti-malarials, including mefloquine. In the present study, we have taken advantage of drug encapsulation approach to elevate the anti-malarial potential of mefloquine.

Modified PCR-based assay for the differentiation of members of Anopheles fluviatilis complex in consequence of the discovery of a new cryptic species (species V).

Background: Anopheles fluviatilis is a species-complex comprising of four cryptic species provisionally designated as species S, T, U and V. Earlier, a 28S-rDNA based allele-specific polymerase chain reaction (ASPCR) assay was developed for the differentiation of the then known three members of the An. fluviatilis complex, i.

Identification of a Stelar-Localized Transport Protein That Facilitates Root-to-Shoot Transfer of Chloride in Arabidopsis.

Under saline conditions, higher plants restrict the accumulation of chloride ions (Cl(-)) in the shoot by regulating their transfer from the root symplast into the xylem-associated apoplast. To identify molecular mechanisms underpinning this phenomenon, we undertook a transcriptional screen of salt stressed Arabidopsis (Arabidopsis thaliana) roots. Microarrays, quantitative RT-PCR, and promoter-GUS fusions identified a candidate gene involved in Cl(-) xylem loading from the Nitrate transporter 1/Peptide Transporter family (NPF2.

Characterization of ion contents and metabolic responses to salt stress of different Arabidopsis AtHKT1;1 genotypes and their parental strains.

Plants employ several strategies to maintain cellular ion homeostasis under salinity stress, including mediating ion fluxes by transmembrane transport proteins and adjusting osmotic pressure by accumulating osmolytes. The HKT (high-affinity potassium transporter) gene family comprises Na(+) and Na(+)/K(+) transporters in diverse plant species, with HKT1;1 as the only member in Arabidopsis thaliana. Cell-type-specific overexpression of AtHKT1;1 has been shown to prevent shoot Na(+) overaccumulation under salinity stress.

AtHKT1;1 mediates nernstian sodium channel transport properties in Arabidopsis root stelar cells.

The Arabidopsis AtHKT1;1 protein was identified as a sodium (Na⁺) transporter by heterologous expression in Xenopus laevis oocytes and Saccharomyces cerevisiae. However, direct comparative in vivo electrophysiological analyses of a plant HKT transporter in wild-type and hkt loss-of-function mutants has not yet been reported and it has been recently argued that heterologous expression systems may alter properties of plant transporters, including HKT transporters. In this report, we analyze several key functions of AtHKT1;1-mediated ion currents in their native root stelar cells, including Na⁺ and K⁺ conductances, AtHKT1;1-mediated outward currents, and shifts in reversal potentials in the presence of defined intracellular and extracellular salt concentrations.

Assessing the role of root plasma membrane and tonoplast Na+/H+ exchangers in salinity tolerance in wheat: in planta quantification methods.

This work investigates the role of cytosolic Na+ exclusion in roots as a means of salinity tolerance in wheat, and offers in planta methods for the functional assessment of major transporters contributing to this trait. An electrophysiological protocol was developed to quantify the activity of plasma membrane Na+ efflux systems in roots, using the microelectrode ion flux estimation (MIFE) technique. We show that active efflux of Na+ from wheat root epidermal cells is mediated by a SOS1-like homolog, energized by the plasma membrane H+-ATPase.

Type-B response regulators ARR1 and ARR12 regulate expression of AtHKT1;1 and accumulation of sodium in Arabidopsis shoots.

Soil salinity affects a large proportion of the land worldwide, forcing plants to evolve a number of mechanisms to cope with salt stress. Cytokinin plays a role in the plant response to salt stress, but little is known about the mechanism by which cytokinin controls this process. We used a molecular genetics approach to examine the influence of cytokinin on sodium accumulation and salt sensitivity in Arabidopsis thaliana.

Contrast in chloride exclusion between two grapevine genotypes and its variation in their hybrid progeny.

Potted grapevines of 140 Ruggeri (Vitis berlandieri × Vitis rupestris), a good Cl(-) excluder, and K 51-40 (Vitis champinii × Vitis riparia 'Gloire'), a poor Cl(-) excluder, and of a family obtained by crossing the two genotypes, were used to examine the inheritance of Cl(-) exclusion. Rooted leaves were then used to further investigate the mechanism for Cl(-) exclusion in 140 Ruggeri. In both a potting mix trial (plants watered with 50 mM Cl(-)) and a solution culture trial (plants grown in 25 mM Cl(-)), the variation in Cl(-) accumulation was continuous, indicating multiple rather than single gene control for Cl(-) exclusion between hybrids within the family.

Shoot Na+ exclusion and increased salinity tolerance engineered by cell type-specific alteration of Na+ transport in Arabidopsis.

Soil salinity affects large areas of cultivated land, causing significant reductions in crop yield globally. The Na+ toxicity of many crop plants is correlated with overaccumulation of Na+ in the shoot. We have previously suggested that the engineering of Na+ exclusion from the shoot could be achieved through an alteration of plasma membrane Na+ transport processes in the root, if these alterations were cell type specific.

Root plasma membrane transporters controlling K+/Na+ homeostasis in salt-stressed barley.

Plant salinity tolerance is a polygenic trait with contributions from genetic, developmental, and physiological interactions, in addition to interactions between the plant and its environment. In this study, we show that in salt-tolerant genotypes of barley (Hordeum vulgare), multiple mechanisms are well combined to withstand saline conditions. These mechanisms include: (1) better control of membrane voltage so retaining a more negative membrane potential; (2) intrinsically higher H(+) pump activity; (3) better ability of root cells to pump Na(+) from the cytosol to the external medium; and (4) higher sensitivity to supplemental Ca(2+).

The Na+ transporter AtHKT1;1 controls retrieval of Na+ from the xylem in Arabidopsis.

HKT-type transporters appear to play key roles in Na(+) accumulation and salt sensitivity in plants. In Arabidopsis HKT1;1 has been proposed to influx Na(+) into roots, recirculate Na(+) in the phloem and control root : shoot allocation of Na(+). We tested these hypotheses using (22)Na(+) flux measurements and ion accumulation assays in an hkt1;1 mutant and demonstrated that AtHKT1;1 contributes to the control of both root accumulation of Na(+) and retrieval of Na(+) from the xylem, but is not involved in root influx or recirculation in the phloem.