Antioxidant Defense and Flavonoid Accumulation in Saffron Under Viral Stress: A Metabolomic Approach

Saffron ( Crocus sativus L.), valued for its culinary and medicinal properties, is increasingly affected by viral infections that compromise its biochemical integrity and market quality. This study investigates the impact of cucumber mosaic virus (CMV; Cucumovirus CMV ) and turnip mosaic virus (TuMV; Potyvirus rapae ) on saffron’s antioxidant profile, flavonoid content, and physiological parameters. Sixteen traits were quantified, including enzymatic antioxidants (CAT, POD, PPO, PAL), non-enzymatic markers (Trolox, vitamin C, proline), total flavonoids and phenolics, gas exchange parameters (Ci, Cond, VpdL), and morphological indicators. Principal component analysis (PCA) revealed that antioxidant-related traits contributed strongly to the first principal component (F1), explaining 78.29% of the total variance. Viral infection led to elevated antioxidant enzyme activity and flavonoid accumulation, alongside reduced stomatal conductance and altered water vapor dynamics. These findings suggest that CMV and TuMV induce oxidative stress responses and metabolic shifts that may affect saffron’s nutritional and sensory quality. Integrative biochemical profiling offers a valuable approach for assessing viral impact and guiding crop management strategies.