Department of Plant Physiology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland.
Department of Plant Physiology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland.
Ecotoxicol Environ Saf. 2016 Feb;124:480-488. doi: 10.1016/j.ecoenv.2015.11.024. Epub 2015 Nov 28.
The contribution of methyl jasmonate (MJ) as a signal molecule able to take part in the defense mechanism against copper (Cu)-imposed oxidative stress was studied in the leaves and roots of runner bean (Phaseolus coccineus) plants. Roots of plants cultivated hydroponically were preincubated in MJ (10µM) for 1h or 24h and subsequently exposed to Cu (50µM) for 5h (short-term experiment) or 5 days (long-term experiment). Enzymatic (activity of superoxide dismutase, SOD; catalase, CAT; ascorbate peroxidase, APX; guaiacol peroxidase, POX) and non-enzymatic (accumulation of malondialdehyde, MDA; homoglutathione, hGSH; proline; anthocyanins; low molecular weight organic acids, LMWOAs) responses were determined in the leaves and roots. The antioxidative defense mechanism was significantly activated after Cu supplementation. In most cases, activities of ROS (reactive oxygen species) scavenging enzymes like SOD, CAT, APX, POX, as well as MDA, hGSH and proline concentrations increased following Cu exposure. MJ showed a time-dependent effect on antioxidative enzymes activity. In the short-term experiment, MJ elevated CAT, APX and POX activities in the roots, and POX activity in the leaves of non-Cu-treated plants. In the long-term experiment, MJ not only decreased POX and partially CAT activity in the roots, but also increased the MDA level and partially CAT activity in the leaves of the control plants. In Cu-treated plants, MJ reduced APX, but elevated POX activity in the leaves after 5-h exposure. After 5-day-Cu treatment, MJ inhibited POX activity in the leaves and mainly reduced SOD and CAT activities in the roots. Moreover, in the long-term experiment, MJ reduced tartrate and pyruvate in the leaves of Cu-stressed plants, but mostly elevated tartrate and malate in the roots comparing with Cu alone treatment. MJ alone and under Cu excess did not alter accumulation of MDA, hGSH and proline comparing with Cu alone, but partially elevated anthocyanin concentration. The results indicated that MJ was both partially potent in modifying the antioxidative enzymes activity and metabolites accumulation in non-stress and Cu-stress conditions.
茉莉酸甲酯（MJ）作为一种能够参与防御铜（Cu）引起的氧化应激的信号分子的贡献，在菜豆（Phaseolus coccineus）植物的叶片和根中进行了研究。水培种植的植物的根在 MJ（10µM）中预孵育 1 小时或 24 小时，然后暴露于 Cu（50µM）5 小时（短期实验）或 5 天（长期实验）。在叶片和根中测定了酶（超氧化物歧化酶，SOD；过氧化氢酶，CAT；抗坏血酸过氧化物酶，APX；愈创木酚过氧化物酶，POX）和非酶（丙二醛，MDA；还原型谷胱甘肽，hGSH；脯氨酸；花青素；低分子量有机酸，LMWOAs）的反应。在 Cu 补充后，抗氧化防御机制显著激活。在大多数情况下，Cu 暴露后，清除 ROS（活性氧）的酶如 SOD、CAT、APX、POX 的活性以及 MDA、hGSH 和脯氨酸的浓度增加。MJ 对抗氧化酶活性表现出时间依赖性效应。在短期实验中，MJ 提高了非 Cu 处理植物根中的 CAT、APX 和 POX 活性，以及叶片中的 POX 活性。在长期实验中，MJ 不仅降低了根中的 POX 和部分 CAT 活性，而且增加了对照植物叶片中的 MDA 水平和部分 CAT 活性。在 Cu 处理的植物中，MJ 在 5 小时暴露后降低了 APX，但提高了叶片中的 POX 活性。经过 5 天的 Cu 处理后，MJ 抑制了叶片中的 POX 活性，主要降低了根中的 SOD 和 CAT 活性。此外，在长期实验中，MJ 降低了 Cu 胁迫植物叶片中的酒石酸和丙酮酸，但与单独 Cu 处理相比，主要增加了根中的酒石酸和苹果酸。与单独 Cu 相比，MJ 单独处理和 Cu 过量处理并未改变 MDA、hGSH 和脯氨酸的积累，但部分提高了花青素的浓度。结果表明，MJ 既能在非胁迫和 Cu 胁迫条件下部分调节抗氧化酶活性，又能部分调节代谢物的积累。
