background and objectives: drought stress is one of the most important environmental factors reducing growth and yield of crops, especially in arid and semiarid regions of the world. during drought stress, nutrient uptake diminishes due to rising of solute concentrations and so increasing of osmotic potential in the root zone. with increasing soil ph, micronutrient uptake decreases more than ot...

The lumenal ionic content of an organelle is determined by its complement of channels and transporters. These proteins reach their resident organelles by adaptor-dependent mechanisms. This concept is illustrated in AP-3 deficiencies, in which synaptic vesicle zinc is depleted because the synaptic-vesicle-specific zinc transporter 3 does not reach synaptic vesicles. However, whether zinc transpo...

Streptococcus pneumoniae requires manganese for colonization of the human host, but the underlying molecular basis for this requirement has not been elucidated. Recently, it was shown that zinc could compromise manganese uptake and that zinc levels increased during infection by S. pneumoniae in all the niches that it colonized. Here we show, by quantitative means, that extracellular zinc acts i...

Uptake and elimination kinetics of zinc and cadmium were studied in the oligochaetes Enchytraeus albidus and Eisenia fetida. Even at the highest exposure concentrations where E. fetida survived, the internal zinc concentration was still regulated to a constant level. Enchytraeus albidus could not regulate the internal zinc concentration as well, and the body burden increased after exposure to h...

In order to investigate the effect of growth media and nutrition method on the growth of Bellis perennis L. and nutrients uptake, a factorial experiment was conducted with two factors: growth media (municipal waste compost, Azolla compost, tea wastes compost) and nutrition method (without fertilizer, soil application, foliar spray) in comparison to the control medium (60% soil + 20% manure + 10...

Zinc is an essential nutrient for bacterial growth. Because host cells can restrict pathogen access to zinc as an antimicrobial defense mechanism, intracellular pathogens such as Francisella must sense their environment and acquire zinc in response. In many bacteria, the conserved transcription factor Zur is a key regulator of zinc acquisition. To identify mechanisms of zinc uptake in Francisel...

Aspergillus oryzae, Penicillium citrinum and Rhizopus stolonifer isolated from Taif soil, Saudi Arabia could survive in a liquid medium containing up to 500 !lglml Zn. Aspergillus oryzae and Penicillium citrinum were more tolerant to zinc toxicity than Rhizopus stolonifer. The resistance and accumulation of zinc in the tested fungi were discussed according to tolerance index and zinc uptake in ...

Farnesyltransferase enzyme (FTase) is considered an essential enzyme in the Ras signaling pathway associated with cancer. Thus, designing inhibitors for this enzyme might lead to the discovery of compounds with effective anticancer activity. In an attempt to obtain effective FTase inhibitors, pharmacophore hypotheses were generated using structure-based and ligand-based approaches built in Disc...

zinc is one of the most important micronutrient with essential role in biochemical regulation of the body functions. the importance of zinc in pregnancy period was widely studied in various countries. variation in zinc plasma levels during pregnancy needs more investigation, because maternal zinc deficiencies may cause some severe abnormalities in the fetus. in this study the plasma levels of z...