This work examined the capability of Imperata cylindrica to respond, tolerate and accumulate Cu when growing at high Cu concentration (300 mg kg⁻¹ of substrate) at different times of exposure (2, 14 and 21 days). The Cu accumulation in plants was examined by atomic absorption spectroscopy (AAS) and Cu localized by Scanning Electron Microscopy-Energy Dispersive X-Ray spectroscopy. Additionally, the phenolic compound identifications and concentrations were determined using liquid chromatography coupled to mass spectrometry. Our results showed that root biomass decreased significantly at high Cu levels, with a greater decrease at 21 days (39.8% less biomass in comparison to control). The root showed 328 mg Cu kg⁻¹ dry weight at 21 days of exposure to Cu, being the tissue that accumulates most of the Cu. Lipid peroxidation was a clear indicator of Cu stress, principally in shoots. The exposure to Cu significantly increased the synthesis of phenolic compounds in shoots of plants exposed 21 days to Cu, where 5-caffeoylquinic acid reached the highest concentrations. Our results support that I. cylindrica is a Cu accumulator plant in root organs with a medium level of accumulation (between 200–600 mg Cu kg⁻¹ biomass), which can tolerate the exposure to high Cu levels by means of increasing the synthesis of phenolic compound in shoots, suggesting a potential use as phytoremediation tool in Cu polluted environments.

中文翻译：

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潜在植物对铜污染环境进行生物修复的植物白茅（Imperata Cylindrica）中酚类化合物的抗氧化反应和铜的固定化

这项工作研究了在不同暴露时间（2、14和21天）以高Cu浓度（300 mg kg ^-1底物）生长时，Imperata cylindrica对Cu的响应，耐受和积累的能力。植物中的铜积累通过原子吸收光谱法（AAS）进行检查，并且铜通过扫描电子显微镜-能量色散X射线光谱法进行定位。另外，酚类化合物的鉴定和浓度使用液相色谱-质谱联用确定。我们的结果表明，高铜水平下根系生物量显着下降，在21天时下降幅度更大（与对照相比，生物量减少39.8％）。根显示328 mg Cu kg ^-1接触铜21天后的干重，即组织中积累的大部分铜。脂质过氧化是铜胁迫的明确指标，主要在芽中。暴露于铜显着提高了暴露于铜第21天的植物的枝条中酚类化合物的合成，其中5-咖啡酰奎尼酸达到最高浓度。我们的研究结果表明，cylindrica是根器官中的一种Cu累积植物，具有中等水平的积累（200–600 mg Cu kg ^-1生物量之间），可以通过增加草甘膦的合成来耐受高含量的Cu。芽中的酚类化合物，表明在铜污染的环境中有可能用作植物修复工具。