| 摘要: |
| 为揭示铜污染对红树植物的毒性效应和植物的抗性机制, 作者研究了红树植物秋茄(Kandelia obovata)幼苗在不同质量浓度的Cu2+(0, 0.5, 5, 50, 100, 200 mg/L)离子胁迫90 d后, 幼苗生长、部分生理指标的变化以及Cu2+在幼苗体内的累积情况。测定的主要参数有: 幼苗的主根长度、侧根数目、生物量、叶片的光合速率、色素含量、可溶性糖和蛋白含量及抗氧化酶系活性。研究结果表明: 当Cu2+浓度范围在(0.5～200 mg/L)时, 主根长度、侧根数目、生物量、叶片的光合速率、色素含量、可溶性糖和蛋白含量均呈降低趋势; 根系POD活性持续升高, 叶片和根系的SOD和CAT活性呈先升后降趋势;根系MDA含量在整个Cu2+胁迫浓度范围保持相对稳定, 叶片MDA含量在高浓度Cu2+胁迫下增加Cu2+主要累积在根部而向地上部分转运的较少。根据不同浓度的Cu2+离子对秋茄幼苗生长及生理特性影响, 秋茄幼苗对Cu2+胁迫的耐受质量浓度范围为5～50 mg/L。 |
| 关键词: 红树植物 秋茄(Kandelia obovata) Cu2+ 抗氧化酶 累积 |
| DOI：10.11759//hykx20140804002 |
| 分类号: |
| 基金项目:国家自然科学青年基金(41001189); 安徽省教育厅自然科学基金(2015KJ006); 阜阳师范学院自然科学基金校级重点项目(2013FSKJ04ZD) |
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| Growth and physiological characteristics of Kandelia obovata seedlings under Cu2+ stress |
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ZHAO Hu,TANG Jun,ZHENG Wen-jiao
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| Abstract: |
| To reveal the toxic effects of copper on mangroves and the mechanism of plant resistance, the growth of Kandelia obovata seedlings, changes in some of their physiological indices, and the accumulation of copper in them under different copper concentrations were investigated for 90 days. The main parameters that were determined included main root length, lateral root number, biomass, photosynthetic rate, pigment content, soluble sugar and protein contents, and antioxidant enzyme activities. The results showed marked reductions in the main root length, lateral root number, biomass, photosynthetic rate, pigment content, and soluble sugar and protein contents with increasing copper concentration. POD activity was more sensitive to copper stress in the roots than in the leaves. The activities of SOD and CAT first increased and then decreased as the copper concentration increased. The MDA content in the roots remained relatively stable under copper stress, whereas its content in the leaves increased under a high concentration of copper. Copper absorbed by K. obovata was mainly accumulated in the roots, and only a small amount of copper was transferred to the aboveground plant parts. The growth and physiological characteristics of the plant indicated that K. obovata tolerated copper concentrations of approximately 5–50 mg/L. |
| Key words: mangrove Kandelia obovata Cu2+ antioxidant enzymes accumulation |
