Oxidative damage is one of the most harmful effects arising from arsenic (As) toxicity in plants. Herein, the role of exogenous jasmonic acid (JA) in the modulation of As-induced oxidative stress in Lemna valdiviana was investigated. Plants were grown for 24 h in Clark’s nutritive solution containing As (4.0 mg L⁻¹) or As + JA (50, 100, 250 and 500 µM). Chlorophyll a and b content decreased under As stress, either in isolation or associated with JA. The decreased chlorophyll a/b ratio in As-exposed plants was recovered by JA treatment at 100 µM. The carotenoid content was higher in plants exposed to As compared to controls and lower when it was associated with JA. Arsenic triggered the accumulation of O₂^•− and H₂O₂, in addition to severely increasing lipid peroxidation. Application of JA in As-grown plants resulted in lower O₂^•− content and lipid peroxidation than in those grown under As alone, as a result of enhanced SOD activity. On the other hand, H₂O₂ accumulation was increased by JA in As-stressed plants, associated with higher CAT, POX and GPX activity. The As content and bioaccumulation factor (BF) were improved by application of JA in the nutritive solution at 250 and 500 µM. Our findings indicate that JA modulates the pigment balance, thereby fine-tuning energy dissipation as well as alleviating As-induced oxidative damage in L. valdiviana through modulation of ROS homeostasis and improvement of the antioxidant enzymatic system, allowing increased accumulation of As without showing major damage.

氧化损伤是植物中砷（As）毒性引起的最有害的影响之一。在本文中，研究了外源茉莉酸（JA）在Lemna valdiviana中As诱导的氧化应激调节中的作用。使植物在含有As（4.0 mg L ^-1）或As + JA（50、100、250和500 µM）的Clark营养溶液中生长24小时。在砷胁迫下，叶绿素a和b含量降低，无论是单独还是与JA相关。叶绿素a / b降低通过100 µM的JA处理回收了砷暴露植物中的比例。与对照相比，暴露于As的植物中类胡萝卜素含量更高，而与JA结合时则更低。除严重增加脂质过氧化作用外，砷还引发O ₂ ^•-和H ₂ O ₂的积累。由于SOD活性增强，在砷生长的植物中施用JA导致的O ₂ ^•含量和脂质过氧化作用低于在砷单独生长的植物中。另一方面，H ₂ O ₂JA在胁迫植物中的积累增加，这与较高的CAT，POX和GPX活性有关。通过在营养溶液中以250和500 µM的比例施用JA可以提高As含量和生物富集因子（BF）。我们的研究结果表明，JA调制颜料平衡，从而微调能量耗散以及减轻由于诱导的氧化损伤L. valdiviana通过ROS稳态和抗氧化酶体系的改进的调节，允许增加的作为积累而没有显示大损伤。