A Putative Function for the Arabidopsis Fe–Phytosiderophore Transporter Homolog AtYSL2 in Fe and Zn Homeostasis

• DOI: 10.1093/pcp/pci081
• Publication Date: 2005-03-08T01:32:03Z
• Authors: Gabriel Schaaf; Adam Schikora; Jennifer Häberle; Grégory Vert; Uwe Ludewig; Jean-François Briat; Catherine Curie; Nicolaus von Wirén
• Keywords: Heterologous expression

Although Arabidopsis thaliana does not produce phytosiderophores (PS) under Fe deficiency, it contains eight homologs of the metal-PS/metal-nicotianamine (NA) transporter ZmYS1 from maize. This study aimed to investigate whether one closest ZmYS1, AtYSL2, is involved in metal-chelate transport. Northern analysis revealed high expression levels AtYSL2 Fe-sufficient or Fe-resupplied roots, while deficiency transcript decreased. Quantitative real-time polymerase chain reaction (PCR) and transgenic plants expressing an promoter::beta-glucuronidase gene further allowed detection down-regulated Zn deficiency. In contrast did mediate metal-PS metal-NA transport yeast mutants defective Cu uptake, nor Fe(II)-NA-, Fe(III)-NA- Ni(II)-NA-inducible currents when assayed by two-electrode voltage clamp Xenopus oocytes. Moreover, truncation N-terminus remove putative phosphorylation sites that might trigger autoinhibition confer functionality AtYSL2. A direct growth comparison cells transformed with two different vectors showed transformation empty pFL61 repressed even non-limiting supply. We therefore conclude complementation assay previously employed allow identification as Fe-NA transporter. Transgenic root endodermis pericycle facing meta-xylem tubes. Taken together, our investigations support involvement homeostasis, although substrate specificity are likely differ between ZmYS1.