Low doses of exogenous methyl jasmonate applied simultaneously with toxic aluminum improve the antioxidant performance of Vaccinium corymbosum

Aims The effect of different MeJA doses applied prior to or simultaneously with toxic Al on biochemical and physiological properties of Vaccinium corymbosum cultivars with contrasting Al resistance was studied. Methods Legacy (Al-resistant) and Bluegold (Al-sensitive) plants were treated with and without toxic Al under controlled conditions: a) without Al and MeJA, b) 100 mu M Al, c) 100 mu M Al + 5 mu M MeJA, d) 100 mu M Al + 10 mu M MeJA and e) 100 mu M Al + 50 mu M MeJA. MeJA was applied to leaves 24 h prior to or simultaneously with Al in nutrient solution. After 48 h, Al-concentration, lipid peroxidation (LP), H2O2, antioxidant activity, total phenols, total flavonoids, phenolic compounds and superoxide dismutase activity (SOD) of plant organs were analyzed. Results Al-concentrations increased with Al-treatment in both cultivars, being Al, LP and H2O2 concentrations reduced with low simultaneous MeJA application. Higher MeJA doses induced more oxidative damage than the lowest. Legacy increased mainly nonenzymatic compounds, whereas Bluegold increased SOD activity to counteract Al3+. Conclusions Low MeJA doses applied simultaneously with Al3+ increased Al-resistance in Legacy by increasing phenolic compounds, while Bluegold reduced oxidative damage through increment of SOD activity, suggesting a diminution of its Al-sensitivity. Higher MeJA doses could be potentially toxic. Studies are needed to determine the molecular mechanisms involved in the protective MeJA effect against Al-toxicity.