PLANT CELL BIOTECHNOLOGY AND MOLECULAR BIOLOGY

Abiotic stresses, particularly salinity, drought, and heat, pose severe threat to the productivity of major cereal crops, threatening global food security at a time when climate variability is intensifying. Conventional yield-based selection strategies have proven inadequate under these conditions, largely owing to the complexity of genotype × environment interactions that hide the true genetic potential of stress-tolerant lines. Consequently, attention has shifted toward secondary physiological traits as more dependable for stress adaptation. In rice, sodium exclusion capacity and sustained stomatal conductance have been closely associated with salinity tolerance, while in wheat, reduced canopy temperature and high stomatal conductance serve as meaningful markers of drought resilience and yield stability. In sorghum, stay-green lines demonstrate a remarkable capacity to sustain photosynthetic activity under water-deficit conditions, and in maize, reduced anthesis-silking interval alongside stay-green phenotypes confers a measurable advantage under drought stress.

Complementing these physiological insights, multi-omics approaches have substantially advanced our mechanistic understanding of stress adaptation at the molecular and metabolic levels. Metabolomic profiling of wheat and rice under drought conditions has revealed consistent patterns of soluble sugar and osmoprotectant accumulation, while genome-wide association studies and quantitative trait locus mapping have successfully pinpointed genomic regions governing stress-responsive phenotypes. When these molecular tools are coupled with high-throughput phenotyping platforms, the resulting framework offers both precision and scalability in breeding programmes. Collectively, this integrated strategy holds considerable promise for accelerating the development of climate-resilient grain varieties, stabilising crop yields under environmental adversity, and ultimately reducing the vulnerability of agricultural systems to the growing pressures of a changing climate.