Multi-omics intervention in Setaria to dissect climate-resilient traits: Progress and prospects

Abstract

Millets constitute a significant proportion of underutilized grasses and are well known for their climate resilience as well as excellent nutritional profiles. Among millets, foxtail millet (Setaria italica) and its wild relative green foxtail (S. viridis) are collectively regarded as models for studying broad-spectrum traits, including abiotic stress tolerance, C4 photosynthesis, biofuel, and nutritional traits. Since the genome sequence release, the crop has seen an exponential increase in omics studies to dissect agronomic, nutritional, biofuel, and climate-resilience traits. These studies have provided first-hand information on the structure, organization, evolution, and expression of several genes; however, knowledge of the precise roles of such genes and their products remains elusive. Several open-access databases have also been instituted to enable advanced scientific research on these important crops. In this context, the current review enumerates the contemporary trend of research on understanding the climate resilience and other essential traits in Setaria, the knowledge gap, and how the information could be translated for the crop improvement of related millets, biofuel crops, and cereals. Also, the review provides a roadmap for studying other underutilized crop species using Setaria as a model.

Revitalization of small millets for nutritional and food security by advanced genetics and genomics approaches

“…Small millets are small-grained cereals and usually have a lower milling recovery than other grains. Therefore, uniformly sized, unbroken seeds are of concern in small millet production ( Aggarwal et al, 2022 ). The colors vary from black to light yellow-colored grains, with consumers predominantly preferring light yellow- to brown-colored seeds for flour and cooking purposes ( Durgad et al, 2021 ).…”

“…The colors vary from black to light yellow-colored grains, with consumers predominantly preferring light yellow- to brown-colored seeds for flour and cooking purposes ( Durgad et al, 2021 ). Yellow-colored grains are also reportedly more aromatic compared to black grains ( Aggarwal et al, 2022 ). Small millets are also a great source of resistant starch.…”

“…QTL mapping and trait mapping in small millets are in the initial stages; until now, QTL mapping for agronomic traits was performed ( Table 4 ). The QTLs for traits like tiller number, branching, number of spikelets, bristles, panicle length and weight, plant height, grain weight/plant, and pericarp color have been identified in foxtail millet ( Aggarwal et al, 2022 ). In finger millet, Babu (2014 ) and Ramakrishnan et al (2016) identified QTLs for blast, neck blast, and leaf blast.…”

“…The use of other mapping populations like NILs and double haploids remains to be explored ( Vetriventhan et al, 2020 ; Zhang et al, 2021 ). Association mapping in foxtail millet and proso millet were predominantly studied with SSR and SNPs to determine the LD values for the diverse collections ( Aggarwal et al, 2022 ; Boukail et al, 2021 ).…”

“…Dissecting the genes underlying nutritional and therapeutic traits by applying advanced omics will reveal novel metabolic pathways in cereals for biofortification ( Kumar, and Kumar, 2015 ). Next-generation and third-generation crop sequencing and breeding have demonstrated the potential of genetic databases and tools to analyze the genomes of small millets ( Aggarwal et al, 2022 ). Hence, the future relies on developing smart crops with climate resilience, higher nutrition, and therapeutic traits.…”