System Biology of Metal Tolerance in Plants: An Integrated View of Genomics, Transcriptomics, Metabolomics, and Phenomics

Abstract

Heavy metal toxicity is heavily damaging constraint to quality and productivity of crops these days. Plants exposed to heavy metals (HMs) contaminated sites respond at cellular, biochemical, physiological, and molecular levels to cope with lethal effects of heavy metal toxicity. A substantial interest has developed in plant metal tolerance mechanisms especially the ones enabling plants to thrive well in environments having high metals concentrations. Expression of genes in different plant cells, tissues along with expression timing and conditions in cells can be estimated. Gene expression analyses help in determining the response of stress tolerant plants to various environmental conditions including heavy metal stress. Previously, unannotated gene functions can also be inferred by this way. In comparison with practicing techniques, using omic technology is greatly helpful, pragmatic and feasible approach for improving plant systems. The earlier findings point toward omics as a prospective helping hand to engineer heavy metal (s) tolerance in plants. Current developments in various disciplines of biology, for example, genomics, transcriptomics, metabolomics, and phenomics have aided in the characterization of genomes, RNA biology, transcription factors, metabolites, and phenomes gene products involved in metal tolerance in one or the other way, thereby, used for producing heavy metal tolerant crops. The role of genomes (genomics), RNA transcripts (transcriptomics), metabolites (metabolomics), and phenotypes (phenomics) in inducing metal tolerance in plant biological systems under heavy metal toxicity has been summarized in this chapter. We reviewed the deterministic significance of integrated plant omics for heavy metal tolerance and their role in mediating plant responses to HM toxicity. This chapter also summarized the topical developments by the identification and validation of different metal stress-responsive genes, TFs, and miRNAs.