Brassica Plants to Provide Enhanced Human Mineral Nutrition: Selenium Phytoenrichment and Metabolic Transformation

Abstract

It is widely recognized that plants contain nutrients and chemicals that are beneficial beyond general nutrient needs. In fact, research has shown that of the more than 4,000 chemical compounds found in plants, some help prevent the development of disease by interfering with the destructive oxidation of cellular components, and others prevent the development of certain cancers. Moreover, plants can also provide for enhanced mineral nutrition. The same mechanisms that allow plants to extract heavy metals such as lead and uranium can also be applied to the phytoextraction of desirable, beneficial micronutrients, such as selenium, under controlled growing conditions. This process provides for hyperenrichment of the desired micronutrient. Plants containing targeted micronutrients can provide the minimum daily adult requirements in a single tablet or capsule. We describe in this report selected cultivars of Brassica juncea, or Indian mustard, a member of the Brassicaceae (formerly the Cruciferae) containing 2,000 ppm selenium under hydroponic cultivation. The supplied selenium is converted by the plants to organic selenium compounds following the sulfur assimilatory scheme. We present data that confirms the usefulness of Indian mustard and the potential of Astragalus bisulcatus as a source of genetic material for enhancement of selenium biotransformation in the mustard plant.