Premium
Mobilization of vacuolar iron by AtNRAMP3 and AtNRAMP4 is essential for seed germination on low iron
Author(s) -
Lanquar Viviane,
Lelièvre Françoise,
Bolte Susanne,
Hamès Cécile,
Alcon Carine,
Neumann Dieter,
Vansuyt Gérard,
Curie Catherine,
Schröder Astrid,
Krämer Ute,
BarbierBrygoo Hélène,
Thomine Sebastien
Publication year - 2005
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/sj.emboj.7600864
Subject(s) - vacuole , germination , biology , mutant , arabidopsis , phenotype , microbiology and biotechnology , botany , biochemistry , gene , cytoplasm
Iron (Fe) is necessary for all living cells, but its bioavailability is often limited. Fe deficiency limits agriculture in many areas and affects over a billion human beings worldwide. In mammals, NRAMP2/DMT1/DCT1 was identified as a major pathway for Fe acquisition and recycling. In plants, AtNRAMP3 and AtNRAMP4 are induced under Fe deficiency. The similitude of AtNRAMP3 and AtNRAMP4 expression patterns and their common targeting to the vacuole, together with the lack of obvious phenotype in nramp3‐1 and nramp4‐1 single knockout mutants, suggested a functional redundancy. Indeed, the germination of nramp3 nramp4 double mutants is arrested under low Fe nutrition and fully rescued by high Fe supply. Mutant seeds have wild type Fe content, but fail to retrieve Fe from the vacuolar globoids. Our work thus identifies for the first time the vacuole as an essential compartment for Fe storage in seeds. Our data indicate that mobilization of vacuolar Fe stores by AtNRAMP3 and AtNRAMP4 is crucial to support Arabidopsis early development until efficient systems for Fe acquisition from the soil take over.