Optimal nitric oxide treatment preserves strawberry quality by coordinating antioxidant defense and cell wall metabolism

This study systematically examined the effects of nitric oxide (NO) treatment at varying concentrations on physiological metabolism, quality attributes, and antioxidant system regulation in strawberry fruits during postharvest storage. The results indicate that NO treatment significantly delays the increase in decay rate, suppresses respiration rate, and slows down weight loss. It also helps maintain higher levels of total soluble solids (TSS) and titratable acid (TA). The 200 μL L −1 NO treatment demonstrated optimal efficacy in mitigating oxidative damage, as reflected by decreased malondialdehyde (MDA) accumulation and preserved Vitamin C (V C ) content. Furthermore, it enhanced the activity of key antioxidant enzymes while suppressing cell wall-degrading enzymes, effectively delaying fruit softening and maintaining textural stability. Principal component analysis (PCA) of electronic nose data further confirmed that NO treatment stabilized the release patterns of volatile organic compounds. qRT-PCR analysis revealed upregulation of FaSOD , FaPOD , FaCAT , FaAPX , and FaGR genes concomitant with downregulation of FaPG , Faβ-Glu , and FaCEI , indicating a coordinated molecular-level response. Collectively, NO treatment improved strawberry storage quality through multifaceted mechanisms, with the 200 μL L −1 concentration exhibiting superior performance in delaying senescence and preserving sensory-nutritional properties. • NO suppressed respiration rate, stabilizing sugar-acid metabolism and energy balance. • NO treatment boosted antioxidant activity, thereby decreasing ROS accumulation and delaying lipid peroxidation. • NO downregulated FaPG , Faβ-Glu , and FaCEI , maintaining cell wall integrity.