Details

Autor(en) / Beteiligte

• Morel, Mélanie
• Crouzet, Jérôme
• Gravot, Antoine
• Auroy, Pascaline
• Leonhardt, Nathalie
• Vavasseur, Alain
• Richaud, Pierre

Titel

AtHMA3, a P1B-ATPase Allowing Cd/Zn/Co/Pb Vacuolar Storage in Arabidopsis1[W]

Ist Teil von

• Plant physiology (Bethesda), 2009-02, Vol.149 (2), p.894-904

Ort / Verlag

American Society of Plant Biologists

Erscheinungsjahr

2009

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• The Arabidopsis ( Arabidopsis thaliana ) Heavy Metal Associated3 (AtHMA3) protein belongs to the P 1B-2 subgroup of the P-type ATPase family, which is involved in heavy metal transport. In a previous study, we have shown, using heterologous expression in the yeast Saccharomyces cerevisiae , that in the presence of toxic metals, AtHMA3 was able to phenotypically complement the cadmium/lead (Cd/Pb)-hypersensitive strain ycf1 but not the zinc (Zn)-hypersensitive strain zrc1 . In this study, we demonstrate that AtHMA3 in planta is located in the vacuolar membrane, with a high expression level in guard cells, hydathodes, vascular tissues, and the root apex. Confocal imaging in the presence of the Zn/Cd fluorescent probe BTC-5N revealed that AtHMA3 participates in the vacuolar storage of Cd. A T-DNA insertional mutant was found more sensitive to Zn and Cd. Conversely, ectopic overexpression of AtHMA3 improved plant tolerance to Cd, cobalt, Pb, and Zn; Cd accumulation increased by about 2- to 3-fold in plants overexpressing AtHMA3 compared with wild-type plants. Thus, AtHMA3 likely plays a role in the detoxification of biological (Zn) and nonbiological (Cd, cobalt, and Pb) heavy metals by participating in their vacuolar sequestration, an original function for a P 1B-2 ATPase in a multicellular eukaryote.