Department of Chemistry and Biochemistry, University of Québec in Montréal, Case Postal 8888, Succursale Centre-Ville, Montréal, Québec H3C 3P8, Canada.
Plant Physiol Biochem. 2013 Oct;71:235-9. doi: 10.1016/j.plaphy.2013.07.019. Epub 2013 Aug 7.
The toxicity effects of silver (Ag) and the protective role of calcium chloride (CaCl2) was studied in Lemna gibba L. (L. gibba) plants. Silver speciation showed that silver toxicity in L. gibba culture medium can be attributed to free ionic Ag(+) concentration. Frond abscission, intracellular reactive oxygen species (ROS) formation and intracellular uptake of Ag(+) were investigated when L. gibba plants were exposed to AgNO3 concentrations (0.5, 1, 5, and 10 μM) supplemented or not by 10 μM CaCl2. An increase in frond abscission, intracellular ROS and intracellular uptake of Ag(+) were detected in L. gibba plants for all tested concentrations of AgNO3 after 24 h treatment. However, addition of 10 μM CaCl2 to the L. gibba culture medium reduced the toxic effects of Ag by decreasing silver uptake into the plant and intracellular ROS formation. The results suggest that Ag-induced toxicity was attributed to Ag(+) accumulation and chloride was able to protect L. gibba plants against Ag toxicity by formation of complexes with Ag and then alleviation of the metal induced oxidative stress.
研究了银（Ag）的毒性作用和氯化钙（CaCl2）的保护作用在浮萍（L. gibba）植物中的表现。银形态分析表明，浮萍培养液中银的毒性可以归因于游离离子 Ag(+)浓度。当浮萍植物暴露于 AgNO3 浓度（0.5、1、5 和 10 μM）中时，研究了 Frond 脱落、细胞内活性氧（ROS）形成和细胞内 Ag(+)摄取，补充或不补充 10 μM CaCl2。在 24 h 处理后，所有测试浓度的 AgNO3 均导致浮萍植物的 Frond 脱落、细胞内 ROS 和细胞内 Ag(+)摄取增加。然而，向浮萍培养液中添加 10 μM CaCl2 可通过减少 Ag 进入植物和细胞内 ROS 形成来降低 Ag 的毒性作用。结果表明，Ag 诱导的毒性归因于 Ag(+)积累，而氯离子通过与 Ag 形成复合物，然后减轻金属诱导的氧化应激，从而能够保护浮萍植物免受 Ag 毒性的影响。
