Localization and speciation of selenium and mercury in Brassica juncea—implications for Se–Hg antagonism
Abstract
The occurrence and form of selenium and mercury were investigated in Indian Mustard, Brassica juncea, a selenium accumulating plant, which had been co-exposed to varying concentration levels of these two elements. Plants were grown and exposed in hydroponic solutions. Following exposure, root exudates were collected in fresh solutions and the head-space around the aerial portions of the plants was sampled. These samples and the harvested plant tissues were then processed for determination of Se and Hg-containing compounds. For the plant tissues, roots, stems and leaves were separated and extracted using a sequential procedure that removed water-soluble species, water-soluble