Plant ionomics: toward high-throughput nutrient profiling

Abstract Up to two-thirds of the world population is at risk of deficiency in one or more fundamental mineral elements. In order to overcome deficiency disorder of mineral nutrients, a biofortification approach in crops is an absolute requirement to eliminate hidden hunger. Hence the goal of crop biofortification is shifting from food security to nutritional security. In this context, ionomics becomes essential to recognize potential gene(s) responsible for the uptake, transport, and storage of ions in plants. Ionomics is one of the major pillars for the study of structural and functional genomics. It includes the estimation of elemental composition of an organism and changes in its composition in relation to physiological, formative, environmental, and genetic variables. The whole ionomic profiling of the plant is done by various analytical tools fruitfully used to measure elemental composition. Among the best are atomic absorption spectrometry, ion beam analysis, ICP-OES, X-ray crystallography, inductively coupled plasma–mass spectrometry, and neutron activation analysis. These tools gave complete profiles of the ions present in the plants. These data are stored in a database called PiiMS (Purdue Ionomics Information Management System). The vast amount of data available in the database helps the forward and reverse genetic approach for studying the structural and functional genomics of particular organisms. It renders the functional analysis of genes and gene networks that directly or indirectly influence the complete ionome. This chapter discusses the study of ionome with special reference to different types of ionic interaction, quantifications, and gene identification.