Tiny molecules that regulate how plant genes function could eventually help scientists develop a new generation of climate-resilient and nutrient-dense millets, according to a comprehensive scientific review examining the emerging role of microRNAs in millet improvement.

MicroRNAs, commonly abbreviated as miRNAs, are short, non-coding RNA molecules generally around 21–24 nucleotides long. Rather than producing proteins themselves, they regulate gene expression and can influence processes ranging from root development and flowering to stress responses and nutrient transport.

The review, published in Stress Biology, evaluates evidence involving major and minor millets and examines how miRNA networks could contribute to drought tolerance, salinity response, heat adaptation, grain development and micronutrient accumulation.

Researchers highlighted several promising examples. In foxtail millet, miR394 has been associated with drought resistance, while SimiR396d and its target SiGRF1 have been linked with root development and drought tolerance. Research in pearl millet has also identified numerous miRNAs responding to high vapour-pressure deficit and salinity stress.

Finger millet provides another important research direction. The review discusses the Eco-miR169–EcNF-YA13 regulatory module in relation to dehydration and salinity tolerance, demonstrating how particular miRNA-target relationships could become candidates for future crop-improvement programmes.

The potential extends beyond climate adaptation. Researchers are interested in whether miRNA networks can eventually contribute to nutritional biofortification, particularly the accumulation and transport of micronutrients such as iron and zinc.

Pearl millet research has identified pgl-miR159 as a candidate associated with iron metabolism. However, the scientific review explicitly cautions that this association should not yet be interpreted as functional proof that the miRNA increases grain iron accumulation.

That distinction is critical. Despite the considerable potential, millet miRNA science remains at a relatively early stage. Much of the existing research consists of computational predictions, sequencing and expression profiling. Experimentally validated regulatory relationships remain considerably more limited.

The researchers therefore propose a roadmap combining detailed miRNA atlases with degradome sequencing, molecular validation, genomic prediction and intervention technologies including artificial miRNAs, Short Tandem Target Mimics and CRISPR-mediated genome editing.

Such technologies could ultimately allow researchers to modify regulatory pathways influencing stress tolerance or nutritional characteristics rather than relying exclusively on conventional selection.

For the global millet sector, the research demonstrates how advanced molecular biology is beginning to converge with crops historically regarded as under-researched compared with wheat, rice and maize.

The opportunity is significant, but the next phase will depend on moving from promising molecular candidates to experimentally validated traits and ultimately field-tested millet cultivars capable of maintaining their performance across diverse environments.