Insights into chickpea (Cicer arietinum L.) genotype adaptations to terminal drought stress: Evaluating water-use patterns, root growth, and stress-responsive proteins

Chickpea (Cicer arietinum L.), a rainfed crop in semi-arid regions, experiences frequent intermittent drought stress, hindering growth. This study explored morpho-physiological and molecular responses of six chickpea genotypes (ICC 4958, BG 4005, Pusa 362, BGM 10218, RSG 888, ICC 1882) under terminal drought to enhance yield and adaptability. Drought stress was imposed during early podding in a controlled glasshouse experiment. Various physiological, root growth, fertility, and yield parameters were measured. Proteomics analysis was conducted on leaf, pod, and root tissue samples, collected at ~0.3 fraction of transpirable soil water (FTSW). Significant differences occurred for various traits, including phenologies, water relations, pollen viability and germination, flower and pod numbers, abortion rates, photosynthetic apparatus and pigments, osmotic adjustments, canopy temperatures, root length, and densities, and overall yield and biomass. FTSW dynamics can aid genotype screening during early drought. Characterizing stress-responsive proteins can provide insights into cellular processes and adaptations. Terminal drought affected leaf central shoot metabolism, reducing photosynthetic capacity, while roots and pods reconfigured enzyme abundances to promote root growth and pod development. The extensive genotypic variation in proteome data, morpho-physiological traits, and water-use patterns presents opportunities for developing drought-adapted cultivars.