caa a22 4500 606209328 CHVBK 20210128101027.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s00425-015-2250-3 doi (NATIONALLICENCE)springer-10.1007/s00425-015-2250-3 A nitrate-permeable ion channel in the tonoplast of the moss Physcomitrella patens [Elektronische Daten] [Mateusz Koselski, Halina Dziubinska, Aleksandra Seta-Koselska, Kazimierz Trebacz] Main conclusion : In this work, for the first time the activity of nitrate-permeable channels in the tonoplast of the moss Physcomitrella patens was recorded. The channels allowed nitrate flow in one direction—from the cytoplasm to the vacuole. Selectivity of nitrate over chloride of the channels was proved. The activity of the channels was dependent on cytoplasmic calcium, magnesium, and pH. A patch-clamp study carried out on the vacuolar membrane of the moss Physcomitrella patens has revealed that inhibition of cation-selective channels leads to disclosure of channels permeable to NO3 −. These channels were inwardly rectifying and allowed anions to flow from the cytoplasm to the vacuole. After a decrease in the cytoplasmic NO3 − concentration, the current density recorded in the whole-vacuole configuration and amplitude of the currents flowing through single channels were reduced. Application of the NO3 − gradient caused a shift in the reversal potential (Erev) towards ENO3−, indicating NO3 − permeability. Research of the selectivity of the channels to Cl− and NO3 − was also done; it indicated that Cl− is less permeable than NO3 − (PNO3/PCl=3.08). Measurements with different concentrations of cytoplasmic Ca2+ and Mg2+ revealed that the channel was activated by different concentrations of these ions—100µM Ca2+ and 10mMMg2+. Calcium dependence of the channels was also modulated by a redox agent—DTT (dithiothreitol), which added on the cytoplasmic side, caused a reduction in the threshold of channel activation with cytoplasmic Ca2+. The NO3 − permeable channel was also pH dependent. A decrease in the cytoplasmic pH reduced the open probability of the channel; in turn, an increase in the vacuolar pH did not decrease ion channel activity but lowered its conductance. The Author(s), 2015 Anion channels nationallicence Patch-clamp nationallicence Physcomitrella nationallicence Vacuole nationallicence ALMT : Aluminium-activated malate transporter nationallicence BTP : Bis-tris propane nationallicence CAM : Crassulacean acid metabolism nationallicence CDPK : Calcium-dependent protein kinase nationallicence ClC : Chloride channel nationallicence DTT : Dithiothreitol nationallicence EGTA : Ethylene glycol tetraacetic acid nationallicence ENO3 : Reversal potential for nitrate nationallicence NRT : Nitrate transporter nationallicence SV : Slowly activating vacuolar channel nationallicence TRP : Transient receptor potential nationallicence VK : Vacuolar K+ channel nationallicence Koselski Mateusz Department of Biophysics, Institute of Biology and Biochemistry, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland aut Dziubinska Halina Department of Biophysics, Institute of Biology and Biochemistry, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland aut Seta-Koselska Aleksandra Department of Plant Physiology and Biotechnology, Institute of Biotechnology, The John Paul II Catholic University of Lublin, Konstantynow 1i, 20-708, Lublin, Poland aut Trebacz Kazimierz Department of Biophysics, Institute of Biology and Biochemistry, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland aut Planta Springer Berlin Heidelberg 241/5(2015-05-01), 1207-1219 0032-0935 241:5<1207 2015 241 425 https://doi.org/10.1007/s00425-015-2250-3 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00425-015-2250-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Koselski Mateusz Department of Biophysics, Institute of Biology and Biochemistry, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland aut NATIONALLICENCE 700 1- Dziubinska Halina Department of Biophysics, Institute of Biology and Biochemistry, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland aut NATIONALLICENCE 700 1- Seta-Koselska Aleksandra Department of Plant Physiology and Biotechnology, Institute of Biotechnology, The John Paul II Catholic University of Lublin, Konstantynow 1i, 20-708, Lublin, Poland aut NATIONALLICENCE 700 1- Trebacz Kazimierz Department of Biophysics, Institute of Biology and Biochemistry, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland aut NATIONALLICENCE 773 0- Planta Springer Berlin Heidelberg 241/5(2015-05-01), 1207-1219 0032-0935 241:5<1207 2015 241 425