Na+-Dependent High-Affinity Nitrate, Phosphate and Amino Acids Transport in Leaf Cells of the Seagrass Posidonia oceanica (L.) Delile
| Autor: | Delia García-Pérez, José A. Fernández, María J. García-Sánchez, Lourdes Rubio |
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| Rok vydání: | 2018 |
| Předmět: |
inorganic chemicals
0106 biological sciences 0301 basic medicine Posidonia Cytosolic Na+ high-affinity transport NO3− uptake Pi uptake Na+-dependent transport systems amino acid transport Sodium chemistry.chemical_element 01 natural sciences Catalysis lcsh:Chemistry Inorganic Chemistry 03 medical and health sciences chemistry.chemical_compound Nitrate Physical and Theoretical Chemistry lcsh:QH301-705.5 Molecular Biology Spectroscopy Membrane potential chemistry.chemical_classification biology Organic Chemistry food and beverages General Medicine biology.organism_classification Phosphate Computer Science Applications Amino acid Salinity 030104 developmental biology lcsh:Biology (General) lcsh:QD1-999 chemistry Posidonia oceanica Biophysics 010606 plant biology & botany |
| Zdroj: | International Journal of Molecular Sciences, Vol 19, Iss 6, p 1570 (2018) International Journal of Molecular Sciences; Volume 19; Issue 6; Pages: 1570 |
| ISSN: | 1422-0067 |
| Popis: | Posidonia oceanica (L.) Delile is a seagrass, the only group of vascular plants to colonize the marine environment. Seawater is an extreme yet stable environment characterized by high salinity, alkaline pH and low availability of essential nutrients, such as nitrate and phosphate. Classical depletion experiments, membrane potential and cytosolic sodium measurements were used to characterize the high-affinity NO3−, Pi and amino acids uptake mechanisms in this species. Net uptake rates of both NO3− and Pi were reduced by more than 70% in the absence of Na+. Micromolar concentrations of NO3− depolarized mesophyll leaf cells plasma membrane. Depolarizations showed saturation kinetics (Km = 8.7 ± 1 μM NO3−), which were not observed in the absence of Na+. NO3− induced depolarizations at increasing Na+ also showed saturation kinetics (Km = 7.2 ± 2 mM Na+). Cytosolic Na+ measured in P. oceanica leaf cells (17 ± 2 mM Na+) increased by 0.4 ± 0.2 mM Na+ upon the addition of 100 μM NO3−. Na+-dependence was also observed for high-affinity l-ala and l-cys uptake and high-affinity Pi transport. All together, these results strongly suggest that NO3−, amino acids and Pi uptake in P. oceanica leaf cells are mediated by high-affinity Na+-dependent transport systems. This mechanism seems to be a key step in the process of adaptation of seagrasses to the marine environment. |
| Databáze: | OpenAIRE |
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