Journal Article

Comparison of Sulfate and Selenium Accumulation in Relation to the Expression of Sulfate Transporter Genes in Astragalus Species

Buchner, Peter, Cabannes, Emmanuelle, Hawkesford, Malcolm J, Broadley, Martin R

2011

Overview

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.

• Publisher: American Society of Plant Biologists
• Subject: Amino Acid Motifs / Amino Acid Sequence / analysis / Anion Transport Proteins / Anion Transport Proteins - genetics / Anion Transport Proteins - metabolism / Astragalus / Astragalus bisulcatus / Astragalus drummondii / Astragalus glycyphyllos / Astragalus Plant / Astragalus Plant - genetics / Astragalus Plant - metabolism / Astragalus racemosus / Base Sequence / bioaccumulation / Biological Transport / chemistry / Complementary DNA / DNA, Complementary / DNA, Complementary - genetics / DNA, Plant / DNA, Plant - chemistry / DNA, Plant - genetics / gene expression / Gene Expression Regulation, Plant / Genes / genetics / Hyperaccumulators / metabolism / Molecular Sequence Data / Phenotype / Plant Proteins / Plant Proteins - genetics / Plant Proteins - metabolism / Plant Roots / Plant Roots - genetics / Plant Roots - metabolism / Plant Shoots / Plant Shoots - genetics / Plant Shoots - metabolism / Plants / Plants, Genetically Modified / Polymerase chain reaction / quantitative analysis / RNA / RNA - genetics / RNA, Plant / RNA, Plant - genetics / roots / Selenic Acid / Selenic Acid - analysis / Selenic Acid - metabolism / Selenium / Selenium - metabolism / Sequence Alignment / shoots / Starvation / Sulfates / Sulfates - analysis / Sulfates - metabolism / Sulfur / Sulfur - metabolism / transporters / WHOLE PLANT AND ECOPHYSIOLOGY