陈亚慧,刘晓宇,王明新,王静,严新美.蓖麻对镉的耐性、积累及与镉亚细胞分布的关系[J].环境科学学报,2014,34(9):2440-2446
蓖麻对镉的耐性、积累及与镉亚细胞分布的关系
- Cadmium tolerance, accumulation and relationship with Cd subcellular distribution in Ricinus communis L.
- 基金项目：江苏省高校自然科学研究项目（No.14KJB610001）；国家自然科学基金（No.31071350）
- 陈亚慧
- 1. 常州大学环境与安全工程学院, 常州 213164
- 刘晓宇
- 2. 中国环境科学研究院, 北京 100012
- 王明新
- 1. 常州大学环境与安全工程学院, 常州 213164
- 王静
- 1. 常州大学环境与安全工程学院, 常州 213164
- 严新美
- 1. 常州大学环境与安全工程学院, 常州 213164
- 摘要：本研究以淄蓖麻3号为供试材料，通过营养液栽培实验，研究了不同Cd浓度（0、10、25、50、100、200、400 μmol·L-1）对蓖麻生理特性、镉积累和亚细胞分布特征的影响，揭示镉细胞分布特征对镉耐性与积累的影响.结果表明，镉处理对蓖麻叶片丙二醛含量影响不显著，叶绿素含量则对镉具有较强的敏感性，可作为蓖麻镉耐性的评价指标.随着营养液镉含量的增加，蓖麻根、茎、叶镉含量均呈上升趋势，各器官镉含量呈现出根>茎>叶的分配特征，根系对镉具有较强的积累能力和滞留作用.镉在蓖麻根系和叶片各亚细胞组分的含量均为可溶组分 >细胞壁 >细胞器，随着镉胁迫的增加，蓖麻根系细胞壁中镉的相对含量呈增加趋势，可见液泡区隔化和细胞壁固持是蓖麻应对镉胁迫的重要耐性机制.镉在蓖麻体内的茎-叶转移系数为0.35~0.62，而根-茎转移系数仅为0.02~0.11，可见镉从根系向茎的转移能力较弱是降低蓖麻地上部镉富集的重要原因.统计分析表明，蓖麻根系镉的亚细胞分布特征对镉从根向茎的迁移转化能力有显著影响.根-茎转移系数随着根系细胞壁和细胞器镉分配比例的增加而递减，随可溶组分镉分配比例的增加而递增.
- Abstract：A hydroponic experiment was conducted to investigate the physiological parameters, Cd accumulation and subcellular distribution characteristics in energy crop Ricinus communis (Zibima 3) with different Cd doses in nutrient solution (0, 10, 25, 50, 100, 200, 400 μmol·L-1). The results show no significant differences of MDA contents between all Cd treatments. However, chlorophyll contents are sensitive to Cd supply, so it can be used as the Cd tolerance index for Ricinus communis. The Cd contents and uptakes in roots, stems and leaves increase with elevating Cd supply in nutrition solution. The Cd contents in the plant tissues are generally in the sequence root>stem>leaf. The roots demonstrate high accumulation and sequestration capacity of Cd. The Cd subcellular distribution is in the order of soluble fraction >cell wall >organelle in both roots and leaves. In addition, the Cd accumulation percentages in cell wall show increasing trend with elevating Cd supply. Therefore, vacuolar compartmentalization and cell wall binding are supposed to be the main tolerance mechanism to Cd in Ricinus communis. The stem-leaf translocation factors are 0.35~0.62 and the root-stalk transfer coefficients are only 0.02~0.11. Thus, the low translocation ability of cadmium from root to stem may be the limiting factor of accumulation ability in aerial parts of Ricinus communis. Statistical analysis shows significant effects of Cd subcellular distribution on Cd translocation capacity in plants. The root-stem translocation coefficients show negative relationship with the Cd content percentages in the root cell wall and cell organelles, but they are positively related to the Cd content proportions in soluble fractions.
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