Omics-Aided Crop Improvement in Foxtail Millet

One of the oldest cultivated grasses, foxtail millet (Setaria italica (L.) P. Beauv.) is a promising model crop for nutritional studies, stress genomics, and in understanding the molecular basis of biofuel crops owing to its short growing cycle, small diploid genome size, excellent seed production, low repetitive DNA content, and its close relation to leading bioenergy grasses. Foxtail millet is a significant source of good quality protein, fiber, and minerals and offers potential antioxidant properties. The grains are rich in proteins and have unique protein composition dominated by prolamines. A crop with a comparatively smaller genome size of 515 Mb, foxtail millet has the earliest sequenced genome among small millets, offering it the leverage for advancement in modern molecular research. This has helped its progress in omics technologies which primarily aim at the collective detection of genes, transcriptomes, proteins, and metabolites in the crop with diverse applications. Known to be a drought-hardy and salinity-tolerant crop, the genetic basis of these traits has been studied through deep sequencing of RNAs and small RNAs and by analyzing their proteomes. Several of the stress-responsive transcriptional factor families have been systematically studied and database established for further use. Lately, there has been a surge in metabolomics studies in this crop that encompassed comprehensive nutritional profiling and species-specific accumulation of metabolites, stress metabolomics as well as metabolome-based GWAS to understand natural variations, all aiding in crop improvement with breeding applications. Among small millets, foxtail millet is a forerunner in the omics research arena that will be discussed in detail in this chapter.