Deletion of the N-terminal domain of the yeast vacuolar (Na+,K+)/H+ antiporter Vnx1p improves salt tolerance in yeast and transgenic Arabidopsis |
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Authors: | Olivier Cagnac Mourad Baghour Noelia Jaime-Pérez M Nieves Aranda-Sicilia M Elena Sánchez-Romero M Pilar Rodríguez-Rosales Kees Venema |
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Affiliation: | 1. Faculté Pluridisciplinaire de Nador, Université Mohammed Premier, Nador, Morocco;2. Estación Experimental del Zaidín, CSIC, Granada, Spain |
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Abstract: | Cation/proton antiporters play a major role in the control of cytosolic ion concentrations in prokaryotes and eukaryotes organisms. In yeast, we previously demonstrated that Vnx1p is a vacuolar monovalent cation/H+ exchanger showing Na+/H+ and K+/H+ antiporter activity. We have also shown that disruption of VNX1 results in an almost complete abolishment of vacuolar Na+/H+ exchange, but yeast cells overexpressing the complete protein do not show improved salinity tolerance. In this study, we have identified an autoinhibitory N-terminal domain and have engineered a constitutively activated version of Vnx1p, by removing this domain. Contrary to the wild type protein, the activated protein has a pronounced effect on yeast salt tolerance and vacuolar pH. Expression of this truncated VNX1 gene also improves Arabidopsis salt tolerance and increases Na+ and K+ accumulation of salt grown plants thus suggesting a biotechnological potential of activated Vnx1p to improve salt tolerance of crop plants. |
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Keywords: | (Na+ K+)/H+ antiporters Arabidopsis ion transport salt tolerance vacuoles yeast |
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