Abstract:

This study investigated copper-resistant Cinnamomum camphora (L.) Presl in the restoration of a copper-polluted mining area through pot simulation experiments. Six treatment concentrations were established (50, 150, 300, 600, 900, and 1 200 mg/kg), with no copper addition used as the control (CK). After 60 d of treatment, biomass accumulation, chlorophyll content, physiological and biochemical indexes of C. camphora, and copper ion accumulation and transfer were measured. The impact of different copper concentrations on growth, physiological, and biochemical responses in C. camphora, as well as the patterns of copper accumulation and distribution in various tissues, were explored to evaluate copper tolerance in this species. Results showed that C. camphora growth under copper stress was enhanced at low copper concentrations (150 mg/kg) and inhibited at high copper concentrations. Physiological indicators, including superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), hydrogen peroxide (H₂O₂), free proline, and soluble sugar, did not significantly increase under 900 mg/kg copper treatment. glutathione reductase (GR) decreased gradually with the increase of copper concentration, while malondialdehyde (MDA) and glutathione (GSH) contents increased gradually with the increase of copper concentration. Copper was predominantly accumulated in the roots, minimizing toxicity to above-ground tissues, with organ copper content in the order root > leaf > stem. The copper transfer rate (IF) from root to leaf (leaf/root) decreased from 0.078 in the control to 0.007 in the 1 200 mg/kg copper treatment group, while the copper transfer rate (IF) from root to stem (Stem/Root) decreased from 0.06 in the control to 0.005 in the 1 200 mg/kg copper treatment group. Based on growth performance, physiological responses, and copper ion accumulation and transfer, C. camphora exhibited good copper tolerance, withstanding up to 900 mg/kg, highlighting its potential for planting in copper-contaminated soils.

摘要：

以前期在铜污染矿区修复中筛选出的耐铜樟树（Cinnamomum camphora (L.) Presl）为材料，通过盆栽模拟实验，以不添加铜为对照（CK），设置50、150、300、600、900、1 200 mg/kg 6个处理浓度，胁迫处理60 d后，测定樟树的生物量积累、叶绿素含量、生理生化指标及樟树对铜离子的富集和转移量，分析不同浓度铜处理对耐铜樟树生长、生理生化的影响，以及铜在不同组织的富集转运规律。结果显示，樟树对铜胁迫表现出低浓度（150 mg/kg）促进生长，高浓度抑制生长的趋势。超氧化物歧化酶（Superoxide dismutase，SOD）、过氧化物酶（Peroxidase，POD）、过氧化氢酶（Catalase，CAT）、过氧化氢（Hydrogen peroxide，H₂O₂）、游离脯氨酸和可溶性糖含量等生理指标在900 mg/kg处理时没有显著升高；谷胱甘肽还原酶（Glutathione reductase，GR）随着处理浓度的升高逐渐降低；丙二醛（Malondialdehyde，MDA）、谷胱甘肽（Glutathione，GSH）含量则随着处理浓度的升高逐渐升高。各器官铜含量的大小顺序为根>叶>茎，樟树主要将铜富集在根系，往地上茎和叶的转移率很低，极大地降低了对茎、叶的铜毒害作用，且随着处理浓度的增加，铜由根系向叶片的转移率IF（Leaf/Root）由对照处理的0.078逐降至1 200 mg/kg处理时的0.007；铜由根系向茎的转移率IF（Stem/Root）由对照处理的0.06逐降至1 200 mg/kg处理时的0.005。综合其生长、生理及铜的富集转运特性，樟树对铜具有较好的耐受性，耐受浓度可达900 mg/kg，是可用于铜污染土壤种植的理想材料。