This Article Full Text Full Text (PDF) All Versions of this Article: 136/3/3762    most recent pp.104.045005v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (24) Citing Articles via Google Scholar Google Scholar Articles by Wang, Y. Articles by Horst, W. J. Search for Related Content PubMed PubMed Citation Articles by Wang, Y. Articles by Horst, W. J. Agricola Articles by Wang, Y. Articles by Horst, W. J.

ENVIRONMENTAL STRESS AND ADAPTATION

Apoplastic Binding of Aluminum Is Involved in Silicon-Induced Amelioration of Aluminum Toxicity in Maize¹

Institute for Plant Nutrition, University of Hannover, D–30419 Hannover, Germany

The alleviating effect of silicon (Si) supply on aluminum (Al) toxicity was suggested to be based on ex or in planta mechanisms. In our experiments with the Al-sensitive maize (Zea mays) cultivar Lixis, Si treatment but not Si pretreatment ameliorated Al-induced root injury as revealed by less root-growth inhibition and callose formation. Si treatment did not affect monomeric Al concentrations in the nutrient solution, suggesting an in planta effect of Si on Al resistance. A fractionated analysis of Si and Al in the 1-cm root apices revealed that more than 85% of the root-tip Al was bound in the cell wall. Al contents in the apoplastic sap, the symplastic sap, and the cell wall did not differ between –Si and +Si plants. Si did not affect the Al-induced exudation of organic acid anions and phenols from the root apices. However, Al treatment greatly enhanced Si accumulation in the cell wall fraction, reducing the mobility of apoplastic Al. From our data we conclude that Si treatment leads to the formation of hydroxyaluminumsilicates in the apoplast of the root apex, thus detoxifying Al.

Article, publication date, and citation information can be found at www.plantphysiol.org/cgi/doi/10.1104/pp.104.045005.

^* Corresponding author; e-mail horst{at}pflern.uni-hannover.de; fax 49–511–762–3611.

Received April 22, 2004; returned for revision June 15, 2004; accepted June 18, 2004.

This article has been cited by other articles:

				J. L. Yang, Y. Y. Li, Y. J. Zhang, S. S. Zhang, Y. R. Wu, P. Wu, and S. J. Zheng Cell Wall Polysaccharides Are Specifically Involved in the Exclusion of Aluminum from the Rice Root Apex Plant Physiology, February 1, 2008; 146(2): 602 - 611. [Abstract] [Full Text] [PDF]

				P. Illes, M. Schlicht, J. Pavlovkin, I. Lichtscheidl, F. Baluska, and M. Ovecka Aluminium toxicity in plants: internalization of aluminium into cells of the transition zone in Arabidopsis root apices related to changes in plasma membrane potential, endosomal behaviour, and nitric oxide production J. Exp. Bot., December 1, 2006; 57(15): 4201 - 4213. [Abstract] [Full Text] [PDF]

				M. J. HODSON, P. J. WHITE, A. MEAD, and M. R. BROADLEY Phylogenetic Variation in the Silicon Composition of Plants Ann. Bot., November 1, 2005; 96(6): 1027 - 1046. [Abstract] [Full Text] [PDF]

				D. Eticha, A. Stass, and W. J. Horst Localization of aluminium in the maize root apex: can morin detect cell wall-bound aluminium? J. Exp. Bot., May 1, 2005; 56(415): 1351 - 1357. [Abstract] [Full Text] [PDF]