The Use of Hydroponic Growth Systems to Study the Root and Shoot Ionome of Arabidopsis thaliana

Plants provide an important source of minerals for human and animal consumption. There is a general worldwide deficiency of human intake of several essential minerals, including iron, zinc, copper, calcium, magnesium, selenium, and iodine (White & Broadley, 2009). This deficiency exists not only in developing countries, but also in the developed world. On the other hand, excessive amounts of heavy metals in crop plants can endanger the health of humans and livestock. It is, therefore, important to develop crop plants with balanced levels of minerals. Understanding of the genes and processes that control the mineral content of plants can provide the basis for engineering crops with the optimal concentrations of minerals in various organs and tissues. In recent years, there has been increasing interest in determining the elemental composition (ionome) of various plant species and identifying the genes that dominate this composition [reviewed by Baxter (2009), Salt et al. (2008), and Williams & Salt (2009)]. The agriculturally related plants whose ionomes were investigated include the crops rice (Norton et al., 2010) and Brassica napus (Liu et al., 2009), as well as the plant Lotus japonicus, which serves as a model species for legume crops (Chen et al., 2009).