Methyl jasmonate enhances boron toxicity tolerance in strawberry (Fragaria × Ananassa 'Albion') by modulating plant growth, antioxidant defenses, and biochemical responses.

Plants frequently encounter environmental stressors that impair growth, physiology, and metabolism. Among these, boron (B) toxicity is particularly damaging in arid and semi-arid regions due to excessive B accumulation that restricts productivity. Methyl jasmonate (MeJA), a plant signaling molecule, has been shown to mitigate abiotic stress; however, its role in alleviating B toxicity in strawberry remains unclear. This study investigated the effects of foliar-applied MeJA on Fragaria × ananassa 'Albion' grown hydroponically under four B levels (23, 81, 162, and 323 µM) and four MeJA concentrations (0, 25, 50, and 100 µM). Boron toxicity significantly reduced shoot and root biomass, fruit yield, chlorophyll content, and nutrient uptake (N, Ca²⁺, Fe²⁺, Zn²⁺), while elevating oxidative stress indicators including malondialdehyde, hydrogen peroxide, and electrolyte leakage. MeJA application-particularly at 50 µM-partially alleviated these adverse effects. Positive responses included enhanced antioxidant enzyme activities (superoxide dismutase, catalase, ascorbate peroxidase, guaiacol peroxidase), increased osmolytes, improved nutrient balance, and better fruit quality attributes. MeJA also stimulated phenylalanine ammonia-lyase activity and promoted phenolics, flavonoids, and anthocyanins under moderate B stress. In contrast, higher MeJA concentration (100 µM) produced weaker or inconsistent effects under severe toxicity. To our knowledge, this is the first integrated study to evaluate the dose-dependent impact of MeJA on strawberry under B toxicity by simultaneously assessing physiology, biochemical responses, and fruit quality. These findings suggest MeJA as a promising strategy to enhance strawberry stress tolerance, though further field-based studies across cultivars and soil conditions are required for broader validation.