1. A comparison of sulfate and selenium accumulation in relation to the expression of sulfate transporter genes in Astragalus species.
- Author
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Cabannes E, Buchner P, Broadley MR, and Hawkesford MJ
- Subjects
- Amino Acid Motifs, Amino Acid Sequence, Anion Transport Proteins genetics, Astragalus Plant genetics, Base Sequence, Biological Transport, DNA, Complementary genetics, DNA, Plant chemistry, DNA, Plant genetics, Gene Expression Regulation, Plant, Molecular Sequence Data, Phenotype, Plant Proteins genetics, Plant Proteins metabolism, Plant Roots genetics, Plant Roots metabolism, Plant Shoots genetics, Plant Shoots metabolism, Plants, Genetically Modified, RNA genetics, RNA, Plant genetics, Selenic Acid analysis, Sequence Alignment, Sulfates analysis, Anion Transport Proteins metabolism, Astragalus Plant metabolism, Selenic Acid metabolism, Selenium metabolism, Sulfates metabolism, Sulfur metabolism
- Abstract
Sulfate and selenate uptake were investigated in both selenium (Se) hyperaccumulators (Astragalus racemosus and Astragalus bisulcatus) and closely related nonaccumulator species (Astragalus glycyphyllos and Astragalus drummondii). Sulfur (S) starvation increased Se accumulation, whereas increased selenate supply increased sulfate accumulation in both root and shoot tissues. cDNAs for homologs of groups 1 to 4 sulfate transporters were cloned from these Astragalus species to investigate patterns of expression and interactions with sulfate and selenate uptake. In contrast to all other previously analyzed plant species, abundant gene expression of putative sulfate transporters was observed for both Se-hyperaccumulating and nonaccumulating Astragalus, regardless of S and Se status. Furthermore, quantitative analysis of expression indicated a transcript level in Se-hyperaccumulating Astragalus comparable with other plant species under S deprivation. The high expression of sulfate transporters in certain Astragalus species may lead to enhanced Se uptake and translocation ability and therefore may contribute to the Se hyperaccumulation trait; however, it is not sufficient to explain S/Se discriminatory mechanisms.
- Published
- 2011
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