Skip Navigation


JXB Advance Access originally published online on December 14, 2006
Journal of Experimental Botany 2007 58(3):651-658; doi:10.1093/jxb/erl238
This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
58/3/651    most recent
erl238v1
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 ISI Web of Science
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 Babourina, O.
Right arrow Articles by Rengel, Z.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Babourina, O.
Right arrow Articles by Rengel, Z.
Agricola
Right arrow Articles by Babourina, O.
Right arrow Articles by Rengel, Z.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author [2006]. 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

Nitrate supply affects ammonium transport in canola roots

Olga Babourina1, Konstantin Voltchanskii1, Bart McGann1, Ian Newman2 and Zed Rengel1

1School of Earth and Geographical Sciences, M087, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009
2School of Mathematics and Physics, University of Tasmania, GPO Box 252-21, Hobart, Tasmania 7001

* To whom correspondence should be addressed. E-mail: olgab{at}cyllene.uwa.edu.au

Plants may suffer from ammonium (NHFormula) toxicity when NHFormula is the sole nitrogen source. Nitrate (NOFormula) is known to alleviate NHFormula toxicity, but the mechanisms are unknown. This study has evaluated possible mechanisms of NOFormula alleviation of NHFormula toxicity in canola (Brassica napus L.). Dynamics of net fluxes of NHFormula, H+, K+ and Ca2+ were assessed, using a non-invasive microelectrode (MIFE) technique, in plants having different NOFormula supplies, after single or several subsequent increases in external NH4Cl concentration. After an increase in external NH4Cl without NOFormula, NHFormula net fluxes demonstrated three distinct stages: release ({tau}1), return to uptake ({tau}2), and a decrease in uptake rate ({tau}3). The presence of NOFormula in the bathing medium prevented the {tau}1 release and also resulted in slower activation of the {tau}3 stage. Net fluxes of Ca2+ were in the opposite direction to NHFormula net fluxes, regardless of NOFormula supply. In contrast, H+ and K+ net fluxes and change in external pH were not correlated with NHFormula net fluxes. It is concluded that (i) NOFormula primarily affects the NHFormula low-affinity influx system; and (ii) NHFormula transport is inversely linked to Ca2+ net flux.

Key words: Ammonium toxicity, Brassica napus, Ca2+, H+, ion fluxes, nitrate

Received 10 April 2006; Revised 17 October 2006 Accepted 18 October 2006


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.