Genetic Improvement of Drought-Resistant Millet Crops

Millet species, including foxtail, pearl and broomcorn millet, represent vital cereals for arid and semi-arid regions owing to their inherent drought resilience and nutritional value. Genetic improvement efforts have focused on elucidating the molecular mechanisms underlying stress tolerance, developing genomic and breeding resources, and deploying modern biotechnologies to accelerate cultivar development. High-quality genome assemblies have provided reference frameworks for pan-genome analyses, comparative genomics and identification of gene families associated with water-use efficiency, root architecture and osmotic adjustment. Advances in marker-assisted selection and genome-wide association studies have pinpointed quantitative trait loci (QTL) linked to drought-adaptive traits, while transcriptomic and proteomic surveys have revealed networks of stress-responsive transcription factors, hormone pathways and protective enzymes. Complementary approaches using transgenic expression and genome editing tools have validated candidate genes and facilitated rapid trait enhancement. Collectively, these strategies are converging to deliver millet varieties with improved yield stability under water deficit, thereby strengthening food security in vulnerable regions and supporting climate-smart agriculture.

Research from Nature Portfolio

Recent studies have identified a specific E2–E3 ubiquitin-ligase module in foxtail millet that stabilises a key brassinosteroid receptor, enhancing both grain yield and tolerance to environmental stresses. Elite alleles of this module confer improved growth under suboptimal conditions, offering a template for targeted allelic introgression. A chromosome-scale genome assembly of broomcorn millet has uncovered lineage-specific expansions of ubiquitin E3 ligase subunits and the full complement of C4 carbon fixation genes, laying a foundation for dissecting exceptional water-use efficiency. In a complementary effort, a platinum-quality genome of green millet and de novo assemblies of numerous wild accessions have enabled discovery of loci controlling climate-adaptation traits; one locus regulating seed shattering was functionally validated via CRISPR–Cas9 editing, demonstrating the power of precise genome engineering for domestication trait improvement.

Genetic Improvement of Drought-Resistant Millet Crops publication trend

The graph below shows the total number of articles in genetic improvement of drought-resistant millet crops across all publications each year (not limited to Nature Index journals).

Technical terms

Ubiquitination: Covalent attachment of ubiquitin molecules to a protein, regulating its stability or activity.

Quantitative trait locus (QTL): A genomic region that contributes to variation in a measurable trait such as drought tolerance.

C4 photosynthesis: A carbon fixation mechanism that concentrates CO₂ around the enzyme Rubisco, enhancing efficiency under high light and temperature.

Osmolyte: A small organic molecule that accumulates in cells to maintain osmotic balance during water stress.

CRISPR–Cas9: A precise genome editing system that introduces targeted DNA breaks to enable specific genetic modifications.

References

1. An E2-E3 pair contributes to seed size control in grain crops. Nature Communications (2023).
2. Genome-Wide Identification, Bioinformatic Characterization, and Expression Profiling of Starch Synthase (SS) Genes in Foxtail Millet under Drought Condition. Stresses (2024).
3. The genome of broomcorn millet. Nature Communications (2019).
4. A genome resource for green millet Setaria viridis enables discovery of agronomically valuable loci. Nature Biotechnology (2020).
5. Comparative proteomic investigation of drought responses in foxtail millet. BMC Plant Biology (2018).
6. Stable Expression of mtlD Gene Imparts Multiple Stress Tolerance in Finger Millet. PLOS ONE (2014).