High V-PPase activity is beneficial under high salt loads, but detrimental without salinity

Bibliographische Detailangaben
Veröffentlicht in:	The New phytologist. - 1979. - 219(2018), 4 vom: 09. Sept., Seite 1421-1432
1. Verfasser:	Graus, Dorothea (VerfasserIn)
Weitere Verfasser:	Konrad, Kai R, Bemm, Felix, Patir Nebioglu, Meliha Görkem, Lorey, Christian, Duscha, Kerstin, Güthoff, Tilman, Herrmann, Johannes, Ferjani, Ali, Cuin, Tracey Ann, Roelfsema, M Rob G, Schumacher, Karin, Neuhaus, H Ekkehard, Marten, Irene, Hedrich, Rainer
Format:	Online-Aufsatz
Sprache:	English
Veröffentlicht:	2018
Zugriff auf das übergeordnete Werk:	The New phytologist
Schlagworte:	Journal Article Research Support, Non-U.S. Gov't cell death plasma membrane voltage proton pump currents salt vacuolar pH vacuolar proton-ATPase (V-ATPase) vacuolar proton-pyrophosphatase (V-PPase) Diphosphates mehr... Isoenzymes Proton Pumps Protons Sodium Chloride 451W47IQ8X Vacuolar Proton-Translocating ATPases EC 3.6.1.- Inorganic Pyrophosphatase EC 3.6.1.1

Beschreibung
Zusammenfassung:	© 2018 The Authors. New Phytologist © 2018 New Phytologist Trust. The membrane-bound proton-pumping pyrophosphatase (V-PPase), together with the V-type H+ -ATPase, generates the proton motive force that drives vacuolar membrane solute transport. Transgenic plants constitutively overexpressing V-PPases were shown to have improved salinity tolerance, but the relative impact of increasing PPi hydrolysis and proton-pumping functions has yet to be dissected. For a better understanding of the molecular processes underlying V-PPase-dependent salt tolerance, we transiently overexpressed the pyrophosphate-driven proton pump (NbVHP) in Nicotiana benthamiana leaves and studied its functional properties in relation to salt treatment by primarily using patch-clamp, impalement electrodes and pH imaging. NbVHP overexpression led to higher vacuolar proton currents and vacuolar acidification. After 3 d in salt-untreated conditions, V-PPase-overexpressing leaves showed a drop in photosynthetic capacity, plasma membrane depolarization and eventual leaf necrosis. Salt, however, rescued NbVHP-hyperactive cells from cell death. Furthermore, a salt-induced rise in V-PPase but not of V-ATPase pump currents was detected in nontransformed plants. The results indicate that under normal growth conditions, plants need to regulate the V-PPase pump activity to avoid hyperactivity and its negative feedback on cell viability. Nonetheless, V-PPase proton pump function becomes increasingly important under salt stress for generating the pH gradient necessary for vacuolar proton-coupled Na+ sequestration
Beschreibung:	Date Completed 25.09.2019 Date Revised 13.12.2023 published: Print-Electronic Citation Status MEDLINE
ISSN:	1469-8137
DOI:	10.1111/nph.15280