Gene expression polymorphisms associated with hyperaccumulation of selenium in Symphyotrichum ascendens (Western aster)

Symphyotrichum ascendens is responsible for the selenium poisoning of livestock and wildlife grazing on disturbed soils in the phosphate-mining region of the American Intermountain West. Goals of this study were to determine gene expression profiles and gene functions associated with selenate uptake, partitioning, and growth in S. ascendens. Plant growth and gene expression profiles were characterized using an RNAseq approach from roots and shoots of plants grown at selenium concentrations of 0.0, 0.1, 0.25, 0.5, and 1.0 mM from hydroponic solution. Selenium uptake increased with increasing solution concentration, with a leaf concentration reaching 3.6 % at the highest treatment concentration, which would be highly toxic to livestock and wildlife.