Spectral light quality regulates photosynthesis and thylakoidal protein complexes to improve drought tolerance in okra rootstocks

Infrared thermographic images showed lower canopy temperatures, indicating increased water content under R:B light conditions. NS-7774 exhibited improved drought tolerance confirmed by decreased malondialdehyde (MDA) levels and enhanced antioxidant enzyme activity. Metabolic stability was indicated by preserved photosynthetic protein complexes and stress-responsive polypeptides in the thylakoidal multiprotein complex profiling. Nutrient preservation was validated through SEM-EDAX analysis, assessments of chlorophyll, total soluble protein, isoenzyme patterns, and antioxidant activity (CAT, SOD, APX, GPOX). Multivariate analysis highlighted six critical factors contributing to resilience. These results demonstrate that combinational spectral light modifications can greatly increase the tolerance of okra to drought. The superior performance of NS 7774 under R:B light conditions suggests the potential suitability of NS 7774 for cultivation in drought-prone zones of India.