Ionomics: Using Elemental Profiling to Understand the Genetic and Physiological Mechanisms that Enable Plants to Adapt to Their Environment

The vast majority of the elements that make up a seed, with the exception of carbon and oxygen, are obtained from soil via the roots.  These soil-derived elements are required for plant structure, metabolism, protein function, signaling, and proper osmotic and electrostatic potential.  Elemental accumulation requires the integration of processes across biological scales, including interactions with the soil matrix and biota, subcellular localization, metabolism, and gas exchange. Thus, the elemental composition of seeds (the “ionome”), including both beneficial and toxic elements, is a consequence of complex plant-environment interactions with serious nutritional implications.  High-throughput ionomics workflows allow a single inductively coupled plasma mass spectrometer (ICP-MS) to precisely analyze hundreds of samples for more than 20 elements per day. We have used ionomic profiling of 35,000+ maize kernels and 25,000+ soybeans to detect the genetic and environmental determinants of the ionome.  We are analyzing the maize diversity panel and nested association mapping population as well as mutagenized soybean populations and Soybean RILs.