Unequal functional redundancy between the two Arabidopsis thaliana high-affinity sulphate transporters SULTR1;1 and SULTR1;2.
* In Arabidopsis, SULTR1;1 and SULTR1;2 are two genes proposed to be involved in high-affinity sulphate uptake from the soil solution. We address here the specific issue of their functional redundancy for the uptake of sulphate and for the accumulation of its toxic analogue selenate with regard to plant growth and selenate tolerance. * Using the complete set of genotypes, including the wild-type, each one of the single sultr1;1 and sultr1;2 mutants and the resulting double sultr1;1-sultr1;2 mutant, we performed a detailed phenotypic analysis of root length, shoot biomass, sulphate uptake, sulphate and selenate accumulation and selenate tolerance. * The results all ordered the four different genotypes according to the same functional hierarchy. Wild-type and sultr1;1 mutant plants displayed similar phenotypes. By contrast, sultr1;1-sultr1;2 double-mutant plants showed the most extreme phenotype and the sultr1;2 mutant displayed intermediate performances. Additionally, the degree of selenate tolerance was directly related to the seedling selenate content according to a single sigmoid regression curve common to all the genotypes. * The SULTR1;1 and SULTR1;2 genes display unequal functional redundancy, which leaves open for SULTR1;1 the possibility of displaying an additional function besides its role in sulphate membrane transport.
Barberon
Marie
M
UMR de Biochimie et Physiologie Moléculaire des Plantes, Centre International d'Etudes Supérieures en Sciences Agronomiques, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Montpellier II, 2 Place Pierre Viala, 34060 Montpellier cedex 1, France.
Berthomieu
Pierre
P
UMR de Biochimie et Physiologie Moléculaire des Plantes, Centre International d'Etudes Supérieures en Sciences Agronomiques, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Montpellier II, 2 Place Pierre Viala, 34060 Montpellier cedex 1, France.
Clairotte
Michael
M
UMR de Biogéochimie du Sol et de la Rhizosphère, Centre International d'Etudes Supérieures en Sciences Agronomiques, Institut National de la Recherche Agronomique, 2 Place Pierre Viala, 34060 Montpellier cedex 1, France.
Shibagaki
Nakako
N
Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1, Yamadaoka, Suita, Osaka 565-0871, Japan.
Davidian
Jean-Claude
JC
UMR de Biochimie et Physiologie Moléculaire des Plantes, Centre International d'Etudes Supérieures en Sciences Agronomiques, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Montpellier II, 2 Place Pierre Viala, 34060 Montpellier cedex 1, France.
Gosti
Françoise
F
UMR de Biochimie et Physiologie Moléculaire des Plantes, Centre International d'Etudes Supérieures en Sciences Agronomiques, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Montpellier II, 2 Place Pierre Viala, 34060 Montpellier cedex 1, France.