Abiotic stress response mechanisms, molecular mitigation, and future strategies in millets
Abstract
Abiotic stresses, such as drought, salinity, temperature extremes, heavy metals, and pesticide toxicity, severely impact plant growth and productivity, primarily through the accumulation of reactive oxygen species (ROS) and metabolic imbalances. In the era of climate change and declining agricultural sustainability, the development of stress-resilient crops has become essential for ensuring global food and nutritional security. Millets, also known as ‘super grain’ or ‘miracle grain’ due to their nutritional value, are recognized for their inherent resilience and exhibit superior adaptability in arid and semi-arid ecosystems towards these abiotic stresses. It is due to their C4 photosynthetic efficiency, rapid life cycles, and deep root architecture. These cereals deploy integrated morphological, physiological, biochemical, and molecular mechanisms, including antioxidant defense systems, osmolyte accumulation, stress-responsive gene expression, and hormonal regulation to maintain homeostasis under stress. Despite these traits, millet improvement lags behind that of major cereals due to limited breeding efforts and underdeveloped molecular resources. This review focuses on recent advances in stress tolerance mechanisms, highlighting omics-driven insights, microbial and phytohormonal mitigation strategies, and exploring genome editing and modern breeding tools, such as CRISPR/Cas9 and genome-wide association studies (GWAS), for developing climate-resilient millet cultivars suitable for sustainable agriculture and future food security. The article explores the development of climate-resilient millet varieties by integrating molecular innovations into traditional agronomic practices, which will provide future benefits framework for developing new varieties. Overall, the article will deepen understanding of the molecular processes underlying stress responses and provide targeted solutions to enhance stress tolerance in millets.
