Skip Navigation


JXB Advance Access originally published online on February 12, 2009
Journal of Experimental Botany 2009 60(4):1363-1374; doi:10.1093/jxb/erp011
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
60/4/1363    most recent
erp011v1
Right arrow E-letters: Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when E-letters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Queirós, F.
Right arrow Articles by Fidalgo, F.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Queirós, F.
Right arrow Articles by Fidalgo, F.
Agricola
Right arrow Articles by Queirós, F.
Right arrow Articles by Fidalgo, F.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author [2009]. Published by Oxford University Press [on behalf of the Society for Experimental Biology]. All rights reserved. For Permissions, please e-mail: journals.permissions@oxfordjournals.org

RESEARCH PAPER

Activity of tonoplast proton pumps and Na+/H+ exchange in potato cell cultures is modulated by salt

Filipa Queirós1,2, Natacha Fontes3,4, Paulo Silva3,4, Domingos Almeida5,6, Masayoshi Maeshima7, Hernâni Gerós3,4,* and Fernanda Fidalgo1,8

1Departamento de Botânica, Faculdade de Ciências, Universidade do Porto, Ed. FC4, Rua do Campo Alegre, s/nº, 4169-007 Porto, Portugal
2Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto, Portugal
3Departamento de Biologia, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal
4Centro de Investigação e de Tecnologias Agro-Ambientais e Biológicas (CITAB)
5Secção Autónoma Eng.a Ciências Agrárias, Faculdade de Ciências, Universidade do Porto, Rua do Monte, 4485-661 Vairão, Portugal
6CBQF, Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Dr. António Bernardino de Almeida, 4200-072 Porto, Portugal
7Laboratory of Cell Dynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
8Center for Biodiversity, Functional and Integrative Genomics (BioFIG)

* To whom correspondence should be addressed: E-mail: geros{at}bio.uminho.pt

The efficient exclusion of excess Na from the cytoplasm and vacuolar Na+ accumulation are the main mechanisms for the adaptation of plants to salt stress. This is typically carried out by transmembrane transport proteins that exclude Na+ from the cytosol in exchange for H+, a secondary transport process which is energy-dependent and driven by the proton-motive force generated by plasma-membrane and tonoplast proton pumps. Tonoplast enriched-vesicles from control and 150 mM NaCl-tolerant calli lines were used as a model system to study the activity of V-H+-PPase and V-H+-ATPase and the involvement of Na+ compartmentalization into the vacuole as a mechanism of salt tolerance in Solanum tuberosum. Both ATP- and pyrophosphate (PPi)-dependent H+-transport were higher in tonoplast vesicles from the salt-tolerant line than in vesicles from control cells. Western blotting of tonoplast proteins confirmed that changes in V-H+-PPase activity are correlated with increased protein amount. Conversely, immunodetection of the A-subunit of V-H+-ATPase revealed that a mechanism of post-translational regulation is probably involved. Na+-dependent dissipation of a pre-established pH gradient was used to measure Na+/H+ exchange in tonoplast vesicles. The initial rates of proton efflux followed Michaelis–Menten kinetics and the Vmax of proton dissipation was 2-fold higher in NaCl-tolerant calli when compared to the control. H+-coupled exchange was specific for Na+ and Li+ and not for K+. The increase of both the pH gradient across the tonoplast and the Na+/H+ antiport activity in response to salt strongly suggests that Na+ sequestration into the vacuole contributes to salt tolerance in potato.

Key words: Callus tissue, potato, proton transport, salt tolerance, tonoplast vesicles, vacuolar H+-ATPase, vacuolar H+-pyrophosphatase, vacuolar Na+/H+ antiporter

Received 23 September 2008; Revised 11 December 2008 Accepted 8 January 2009


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.