Characterization of Three Functional High-Affinity Ammonium Transporters in Lotus japonicus with Differential Transcriptional Regulation and Spatial Expression

• DOI: 10.1104/pp.103.034322
• Publication Date: 2004-04-14T22:18:21Z
• Authors: Enrica D'Apuzzo; Alessandra Rogato; Ulrike Simon-Rosin; Hicham El Alaoui; Ani Barbulova; Marco Betti; Maria Dimou; Panagiotis Katinakis; Antonio Marquez; Anne-Marie Marini; Michael K. Udvardi; Maurizio Chiurazzi
• Keywords: Lotus japonicus

Abstract Ammonium is a primary source of nitrogen for plants. In legume plants ammonium can also be obtained by symbiotic fixation, and \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{{+}}\) \end{document} regulator early late interaction steps. transporters are likely to play important roles in the control nodule formation as well assimilation. Two new genes, LjAMT1;2 LjAMT1;3, were cloned from Lotus japonicus. Both able complement growth defect yeast (Saccharomyces cerevisiae) transport mutant. Measurement [14C]methylammonium uptake rates competition experiments revealed that each transporter had high affinity \end{document}. The K i was 1.7, 3, 15 μ m LjAMT1;1, 1;2, 1;3, respectively. Real-time PCR higher expression 1;3 genes leaves than roots nodule, with levels decreasing order LjAMT1;1 > 1;2 except flowers, which LjAMT1;3 expressed at level leaves, showed lowest expression. Expression induced deprivation. repressed exposed elevated CO2 concentrations, suppress photorespiration. Tissue cellular localization LjAMT1 expression, using promoter-β-glucuronidase situ RNA hybridization approaches, distinct spatial different organs, including nodules, suggesting differential metabolism these organs.