丁基拉草為台灣使用最廣的水田殺草劑，對一年生雜草的防除有良好效果，但有關植物對其吸收、輸導及代謝等方面的研究尚無完整的報告。本研究以水稻（Oryza sativa L.）品種台農67號及14C標示的丁基拉草為材料，測定水稻幼苗對此殺草劑的吸收、輸導及代謝情形。另外，水稻與兩種水田雜草，稗草（Echinochloa crusgalli(L.)Beauv.）及鴨舌草（Monochoria vaginalis Presl）幼苗之非蛋白質硫醇（non-protein thiols）含量及GST（glutathione S-transferase）的活性大小亦加以比較。丁基拉草容易被稻苗根部吸收，處理24小時後，尚有80﹪的放射活性留在根部，僅有20﹪轉移到地上部，並且大約有50﹪被代謝為水溶性物質。經薄層色層分析結果，最多的代謝物質為丁基拉草-谷胱甘太物（butachlor-glutathione conjugate）。稻苗之非蛋白質硫醇含量及GST活性隨苗齡而改變，苗齡增加，每株地上部之非蛋白質硫醇含量亦增加，但以蛋白質為計算基礎之GST活性則下降。水稻、稗草、及鴨舌草均含有相當高之非蛋白質硫醇含量，但GST活性則以水稻最高，稗草次之，鴨舌草最低。稗草及鴨舌草幼苗對丁基拉草較為敏感，可能與其GST活性較低有關。

Butachlor [2-chloro-N-(2,6-diethylphenyl)-N-(butoxymethyl) acetamide)is one of the most important herbicides for transplante rice (Oryaz sativa L.) weed control in Taiwan. The herbicide was readily absorbed by rice roots. During 24 hours of uptake experiment, 32% of the applied herbicid was absorbed. The pretreatment of the herbbicide for 2 days did not affect the absorption.Of the absorbed herbicide,80% remained in roots, only 20% translocated into shoots, and more than 50% was metabolized to water soluble substances. Thin layer chromatographic (TLC) analysis showed that the Rf value of the most abundam metabolite was the same as butachlor-glutathione conjugate. Rice, barnyard-grass(Echinochloa crusgalli(L.) Beauv) and monochoria(Monochoria vaginalis Presl) seedlings contained rclatively high level of non-protein thiols, whilc the glutathione S-transferase (GST) activity was highest in ric, barnyardgrass the next, monochlorla the lowest. The difference in GST activity among these species might be related to their sensitivity to butachlor.