United States Department of Agriculture-Agricultural Research Service, P. O. Box 225, Stoneville, Mississippi 38776.
Plant Physiol. 1985 Nov;79(3):862-6. doi: 10.1104/pp.79.3.862.
The herbicide acifluorfen (2-chloro-4-(trifluoromethyl)phenoxy-2-nitrobenzoate) causes strong photooxidative destruction of pigments and lipids in sensitive plant species. Antioxidants and oxygen radical scavengers slow the bleaching action of the herbicide. The effect of acifluorfen on glutathione and ascorbate levels in cucumber (Cucumis sativus L.) cotyledon discs was investigated to assess the relationship between herbicide activity and endogenous antioxidants. Acifluorfen decreased the levels of glutathione and ascorbate over 50% in discs exposed to less than 1.5 hours of white light (450 microeinsteins per square meter per second). Coincident increases in dehydroascorbate and glutathione disulfide were not observed. Acifluorfen also caused the rapid depletion of ascorbate in far-red light grown plants which were photosynthetically incompetent.Glutathione reductase, dehydroascorbate reductase, superoxide dismutase, ascorbate oxidase, ascorbate free radical reductase, peroxidase, and catalase activities rapidly decreased in acifluorfen-treated tissue exposed to white light. None of the enzymes were inhibited in vitro by the herbicide. Acifluorfen causes irreversible photooxidative destruction of plant tissue, in part, by depleting endogenous antioxidants and inhibiting the activities of protective enzymes.
除草剂 acifluorfen（2-氯-4-（三氟甲基）苯氧基-2-硝基苯甲酸酯）会导致敏感植物物种的色素和脂质发生强烈的光氧化破坏。抗氧化剂和氧自由基清除剂可减缓除草剂的漂白作用。本研究调查了 acifluorfen 对黄瓜（Cucumis sativus L.）子叶圆片谷胱甘肽和抗坏血酸水平的影响，以评估除草剂活性与内源性抗氧化剂之间的关系。在暴露于少于 1.5 小时的白光（450 微爱因斯坦/平方米/秒）下，acifluorfen 使谷胱甘肽和抗坏血酸的水平降低了 50%以上。未观察到脱氢抗坏血酸和谷胱甘肽二硫化物的同时增加。acifluorfen 还导致在远红光下生长的植物中抗坏血酸迅速耗尽，这些植物不能进行光合作用。在暴露于白光下的 acifluorfen 处理的组织中，谷胱甘肽还原酶、脱氢抗坏血酸还原酶、超氧化物歧化酶、抗坏血酸氧化酶、抗坏血酸自由基还原酶、过氧化物酶和过氧化氢酶的活性迅速下降。该除草剂在体外均未抑制这些酶。acifluorfen 通过耗尽内源性抗氧化剂和抑制保护酶的活性，导致植物组织不可逆的光氧化破坏。
