Uptake and Translocation of Isouron in Sugarcane Plants

Abstract

Uptake of isouron by sugarcane plants from soil was more rapid during the first 7 weeks than during the later stage. Specific activity in plants reached a maximum in 4-7 weeks. More than 83% of the radioactivity translocated to leaves after 2 weeks. Larger amount of radioactivity was detected in the young leaves at the earlier stage, but most of the activity was found in the old leaves at the late stage after 7 weeks. Up to 7 weeks, 97.7 to 94.4% of the radioactivities were extractable with methanol-water (2:1) from the leaves. Among them, dichloromethane extractable parts decreased from 73.4 to 26.3%, while water soluble fractions increased from 24.6 to 69.4% as the time elapsed. Since 5.4 to 17.7% of the radioactivities in the aqueous phase were extractable with dichloromethane after acid hydrolysis, the existence of metabolites in conjugated form was suggested.