EcoLab, CNRS, Université de Toulouse, Toulouse, France.
EcoLab, Campus INPT-ENSAT, Avenue de l'Agrobiopole - BP 32607, 31326, Castanet Tolosan Cedex, France.
Environ Sci Pollut Res Int. 2019 May;26(14):14106-14115. doi: 10.1007/s11356-019-04630-3. Epub 2019 Mar 10.
Environmentally mediated sensitivity of Lemna minor to copper (Cu) was evaluated for the first time in three experiments: the effects of two levels of nutrient concentration, light irradiance or Cu pre-exposure were tested. Various Cu concentrations (ranging from 0.05 to 0.25 mg/L) were used to assess the sensitivity of L. minor to this metal, using one common strain previously acclimatized to two different levels of light intensity, nutrient enrichment and Cu pre-exposure. Our results showed a phenotypic plastic response of the relative growth rates based on frond number and fresh mass production, and maximum quantum yield of photosystem II (F/F). Growth was affected by the three environmental conditions both prior and during Cu exposure, whereas F/F was mostly affected during Cu exposure. Copper significantly influenced all the parameters measured in the three experiments. Environmental conditions significantly modified L. minor sensitivity to Cu in all experiments, with up to twofold difference depending on the treatment. Growth rate was the parameter that was most impacted. Our study revealed for the first time the existence of phenotypic plasticity in L. minor sensitivity to chemical contamination, and implies that environmental context needs to be taken into account for a relevant risk assessment.
首次在三个实验中评估了环境介导的浮萍对铜（Cu）的敏感性：测试了两种营养浓度水平、光照强度或 Cu 预暴露的影响。使用先前适应两种不同光照强度、营养富集和 Cu 预暴露水平的同一普通品系，我们使用了从 0.05 到 0.25mg/L 的各种 Cu 浓度来评估 L. minor 对这种金属的敏感性。我们的结果表明，基于叶片数和鲜质量产量的相对生长率以及光系统 II（F/F）的最大量子产量存在表型塑性反应。生长受到 Cu 暴露前后三种环境条件的影响，而 F/F 主要在 Cu 暴露期间受到影响。Cu 显著影响了三个实验中测量的所有参数。环境条件在所有实验中显著改变了 L. minor 对 Cu 的敏感性，具体取决于处理，差异可达两倍。生长速度是受影响最大的参数。我们的研究首次揭示了浮萍对化学污染敏感性存在表型可塑性，这意味着需要考虑环境背景来进行相关的风险评估。
