Journal article

Publication year: 2005

Pages: 892-901

Journal: Plant & Cell Physiology

Volume number: 46

Issue number: 6

ISSN: 0032-0781

Open access status: Bronze

DOI Link: https://doi.org/10.1093/pcp/pci094

Publisher: Oxford University Press

Abstract: 
White lupin (Lupinus albus L.) is able to acclimate to phosphorus deficiency by forming proteoid roots that release a large amount of citric acid, resulting in the mobilization of sparingly soluble soil phosphate in the rhizosphere. The mechanisms responsible for the release of organic acids have not been fully elucidated. In this study, we focused on the link between citrate and malate release and the release of H+ and other inorganic ions by proteoid roots of white lupin. The release of citrate was closely correlated with the release of H+, K+, Na+ and Mg2+, but not with that of Ca2+. The stoichiometric relationships between citrate release and the release of H+, K+, Na+ and Mg2+ were 1 : 1.3, 1 : 2.1, 1 : 1.5 and 1 : 0.47, respectively. Similar correlations were found between exudation of malate and cations. During 30 min incubation, fusicoccin addition stimulated H+ and malate release, but not citrate release. A concomitant stimulation of H+, malate and citrate release was measured after 60 min incubation. Vanadate inhibited the release of H+ and malate, but not that of citrate. Anthracene-9-carboxylic acid, an anion channel blocker, caused a concomitant decrease in release of citrate, malate and H+. We conclude that for export of citrate across the plasma membrane of proteoid root cells, H+ release is not strictly related to citrate release. Other cations such as K+ and Na+ can also serve as counterions for citrate release. In contrast, malate release shows a strong H+ release dependency.

Harvard Citation style: Zhu, Y., Yan, F., Zörb, C. and Schubert, S. (2005) A link between citrate and proton release by proteoid roots of white lupin (Lupinus albus L.) grown under phosphorus-deficient conditions?, Plant & Cell Physiology, 46(6), pp. 892-901. https://doi.org/10.1093/pcp/pci094

APA Citation style: Zhu, Y., Yan, F., Zörb, C., & Schubert, S. (2005). A link between citrate and proton release by proteoid roots of white lupin (Lupinus albus L.) grown under phosphorus-deficient conditions?. Plant & Cell Physiology. 46(6), 892-901. https://doi.org/10.1093/pcp/pci094