Omics for proso millet genetic improvement

Proso millet (Panicum miliaceum L.) is one of the seven commonly cultivated millets. It is regarded as a climate-smart, ancient, and gluten-free and therefore, is healthy to humans and the environment. The exceptional nutritional properties of the grain resulted in a gradual surge in its demand in the human food market especially for people with diabetes and celiac disease. It is essential to continue the genetic improvement of proso millet to meet its ever-increasing demand. Genetic improvement of proso millet in the United States, however, is impeded by the narrow genetic base in the germplasm and lack of extensive research on its genetics and breeding. There are lots of reports on 'omics' (genomics, transcriptomics, proteomics, metabolomics, and phenomics) of many common crops and the technologies are being extensively used in their genetic improvement. However, such studies are scarce in proso millet. The objective of this review article is to summarize available 'omics' reports of proso millet and discuss their relevance for its genetic improvement. Relatively more genomics and transcriptomics reports of proso millet are available but only two proteomics and metabolomics reports focusing on grain composition and no phenomics report are available. As more efficient, fast, and cheaper 'omics' technologies are available, it is imperative that global proso and other millets breeders and geneticists collaborate strongly for successful utilization of 'milletomics' for developing of noble proso millet varieties for future need of this climate-smart superfood grain.