Ionomics of Micronutrients in Staple Crops.

Plants take up elements from their soil environment using processes controlled by the genome. The complex nature of these interactions suggests that the elemental profile will be highly plastic with the genetic factors influencing accumulation depending on which environment the plant is grown in. My lab uses high throughput elemental profiling as a tool for understanding plant adaptation. 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 200,000+ maize kernels, soybeans and cotton seeds to detect the genetic and environmental determinants of the ionome. 

 In the first part of my talk, I will focus on our attempts to understand the genetic by environmental interactions that underlie elemental accumulation. We analyzed levels of elements in maize kernels from several populations, including the IBM and NAM populations grown in multiple locations. We looked for loci controlling elemental accumulation both as independent elemental traits and as co-regulated multi-elemental traits identified using principle components analysis. These two approaches identified two overlapping sets of loci linked to elemental accumulation, many of which were found in a single growout. By extending our multi-element phenotypes across all of the growouts, we were able to demonstrate that the growth environment has a profound effect on the elemental profile and that some multi-element phenotypes correlate with specific environmental variables.

 The second part of my talk will describe our attempts to combine quantitative genetics in Maize, Soybean and several other species with computational biology tools to identify the causal genes underlying elemental accumulation.