Nitric Oxide-Mediated Modulation of Biochemical Responses and Leaf Spot Disease Progression in Date Palm (Phoenix dactylifera L.) under Drought Stress

This study investigates the role of sodium nitroprusside (SNP) in enhancing drought tolerance and mitigating leaf spot disease in date palm (Phoenix dactylifera L.). Three SNP concentrations (0, 75, and 150 µM) were applied under progressive drought stress (1, 3, and 6 weeks). The results showed that drought stress significantly increased oxidative stress markers, including malondialdehyde (MDA) and hydrogen peroxide (H₂O₂), while SNP, particularly at 150 µM, reduced their levels. Additionally, SNP treatment enhanced antioxidant enzyme activities (catalase and peroxidase). SNP also reduced the severity of leaf spot symptoms caused by Alternaria alternata, limiting lesion size. These findings suggest that SNP modulates physiological and biochemical responses to drought stress, improving plant defense and disease resistance. Thus, SNP application could be a promising strategy to support the long-term viability of date palm cultivation, particularly in arid regions.