Teisseire H, Couderchet M, Vernet G
Laboratoire de Zoologie et des Sciences de l'Environement, Bâtiment Europol'Agro, Faculté des Sciences, Université des Reims Champagne-Ardenne, Reims, France.
Ecotoxicol Environ Saf. 1998 Jul;40(3):194-200. doi: 10.1006/eesa.1998.1682.
Toxicity of copper and folpet--two fungicides widely used on grape--was evaluated on Lemna minor L., a sensitive aquatic weed regularly used for (eco)toxicological studies. Toxicity assessments were based on inhibition of growth and chlorophyll content of L. minor cultures after 7 days. IC10, IC50, and IC90 were determined for both compounds alone and were respectively, 0.03, 0.16, and 0.95 mg liter-1 for copper and 1.20, 7.50, and > 40 mg liter-1 for folpet. When both compounds were combined, the response of L. minor depended on the initial folpet concentration. Indeed, a slight synergy was observed for 5 mg liter-1 folpet, while at folpet concentrations of 20 to 35 mg liter-1, the two fungicides were antagonists. The antagonism was positively correlated with folpet concentration. Antagonism between Cu and folpet could not be explained by a reduced bioavailability of Cu since concentration of free copper in the mixture did not depend on the presence of folpet. One physiological defense response elicited by copper in plants is an increase in catalase activity. Copper and folpet stimulated catalase activity and changes in the activity of the enzyme could not account for the synergy but possibly for the antagonism. Nevertheless, catalase activity increase significantly after a 24-h exposure to 25 micrograms liter-1 of copper. The use of this property as a rapid and sensitive biomarker to monitor the toxicity of xenobiotics alone or in combination and of environmental water is discussed.
对两种广泛用于葡萄种植的杀菌剂——铜和灭菌丹，在浮萍（Lemna minor L.）上进行了毒性评估，浮萍是一种常用于（生态）毒理学研究的敏感水生杂草。毒性评估基于7天后浮萍培养物生长和叶绿素含量的抑制情况。分别测定了两种化合物单独作用时的IC10、IC50和IC90，铜的数值分别为0.03、0.16和0.95毫克/升，灭菌丹的数值分别为1.20、7.50和>40毫克/升。当两种化合物混合时，浮萍的反应取决于初始灭菌丹浓度。实际上，对于5毫克/升的灭菌丹观察到轻微协同作用，而在灭菌丹浓度为20至35毫克/升时，两种杀菌剂表现为拮抗作用。拮抗作用与灭菌丹浓度呈正相关。铜和灭菌丹之间的拮抗作用无法用铜生物利用度降低来解释，因为混合物中游离铜的浓度并不取决于灭菌丹的存在。植物中铜引发的一种生理防御反应是过氧化氢酶活性增加。铜和灭菌丹刺激了过氧化氢酶活性，该酶活性的变化无法解释协同作用，但可能解释拮抗作用。然而，在暴露于25微克/升铜24小时后，过氧化氢酶活性显著增加。本文讨论了将这一特性用作快速灵敏的生物标志物，以监测单一或混合的外源性物质以及环境水的毒性。
