| 李建秋,龚冰,季节,周子琛,仇浩.砷硒胁迫对小麦毒性效应及预测模型研究[J].农业环境科学学报,2020,39(2):239-246. |
| 砷硒胁迫对小麦毒性效应及预测模型研究 |
| Development of predictive models for quantifying the toxicological responses of wheat to arsenic, selenium, and their binary mixtures |
| 投稿时间：2019-10-08 |
| DOI：10.11654/jaes.2019-1100 |
| 中文关键词: 含氧阴离子型金属 小麦 急性毒性 生物配体模型（BLM） CA/IA模型 |
| 英文关键词: anionic metal (loid) wheat acute toxicity biotic ligand model (BLM) CA/IA model |
| 基金项目:国家重点研发计划项目（2018YFC1800600）；国家自然科学基金面上项目（41877500，41701571） |
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| 中文摘要: |
| 为阐明含氧阴离子型类金属As-Se的联合毒性及其相互作用，以小麦（Triticum aestivum L.）作为模式植物，溶液体系为毒性测试介质，以小麦相对根伸长为毒性终点，系统考察了As、Se单独和复合情况下对小麦的毒性效应，并构建兼具机理性与普适性的模型来预测和评估As-Se的生态毒性效应和风险。结果表明：As、Se单独作用于小麦时，二者都具毒性，基于自由离子活度的EC50值分别为2.88 μmol·L-1和43.51 μmol·L-1，说明As的毒性远大于Se。在As-Se混合体系中，不论是何种剂量表达形式（溶解浓度和自由离子活度剂量），一种阴离子金属的存在都会影响另一种阴离子金属的植物毒性。利用传统浓度加和及独立作用（CA/IA）模型分析和预测As-Se联合毒性作用时，两种模型均高估了其联合毒性，表明As-Se联合作用于小麦时表现为强烈的拮抗作用。进一步将As-Se交互作用纳入在内，构建的阴离子型金属生物配体模型（BLM），可以很好地解释并预测As-Se混合物的交互作用及毒性，拟合度达到0.90，As、Se和生物配体的络合平衡常数分别为logKAsBL=3.28和logKSeBL=1.93。研究表明：BLM框架可拓展应用于含氧阴离子型类金属的毒性预测，为含氧阴离子型类金属联合毒性的精确预测与风险评估提供有效手段。 |
| 英文摘要: |
| To elucidate the mixture toxicity and interactions of As-Se, Triticum aestivum L. was used as the model plant and the solution system as the toxicity test medium. The relative root elongation of wheat was adopted as the toxicological end-point. Toxicity to wheat of As and Se when applied individually and in combination were examined. In addition, a mechanistic based model was developed to predict and evaluate the toxicities and risks of As-Se. Results showed that EC50s(free metal activities at which root elongation was inhibited by 50%) were 2.88 μmol·L-1 and 43.51 μmol·L-1 for As and Se, respectively, indicating that As toxicity was much higher than Se toxicity. In mixture exposures, the presence of As affected the phytotoxicity of Se irrespective of the dose descriptors, and vice versa. Concentration addition and independent action models were used for As-Se mixture toxicity analysis. Both models overestimated the As-Se combined toxicity, indicating that there were strong antagonistic interactions between As and Se. The biotic ligand model(BLM)was developed by incorporating the As-Se interactions for quantifying the mixture toxicity of anionic As and Se. The interactions and toxicities of As-Se mixtures could be well explained and predicted by the BLM(with >90% of toxicity variations explained). Based on cation competition, the derived binding constants for the biotic ligands of wheat logKAsBL and logKSeBL were 3.28 and 1.93, respectively. Our results indicated that the framework of BLM could be extended to predict the toxicities of oxyanions of metal(loid)s, serving as an effective tool for accurate risk assessment of metal (loid) s pollution. |
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