Movement and Fate of p-Nitrophenyl-alpha,alpha,alpha-Trifluoro-2-Nitro-p Tolyl Ether-1'-C in Peanut Seedlings.
Autoradiographs and liquid scintillation counts of peanut (Arachis hypogaea L., var. Starr) seedlings indicate that p-nitrophenyl-alpha,alpha,alpha-trifluoro-2-nitro-p-tolyl ether-1'-(14)C (C-6989) is rapidly absorbed from nutrient solution but only 6.5% of the radioactivity absorbed is translocated to the shoot after 144 hr, with the acropetal movement being confined to the stem and petiole.Metabolism of C-6989 by peanut seedlings proceeds rapidly, the major pathway being hydrolysis of the ether linkage and reduction of the 4-nitrophenol formed to 4-aminophenol. After 48 hr 4-aminophenol, C-6989 and 4-nitrophenol comprised 67.8, 17.4, and 13.5% of the total radioactivity recovered, respectively. After 144 hr these compounds comprised 94.3, 4.0, and 0.9% of the radioactivity, respectively.Reduction of one of the nitro groups of C-6989 followed by hydrolysis of the ether linkage is a minor pathway of metabolism in peanut seedlings. Small amounts (less than 1.0% of the total radioactivity) of both p-mitrophenyl-alpha,alpha,alpha-trifluoro-2-amino-p-tolyl ether and p-amino-phenyl-alpha,alpha,alpha-trifluoro-2-nitro-p-tolyl ether were present but no p-aminophenyl-alpha,alpha,alpha-trifluoro-2-amino-p-tolyl ether was detected. Two very minor metabolites (less than 0.1% of the radioactivity) were detected which were not identified. These metabolites were possibly conjugates of the phenol derivatives with natural plant constituents, or products of substitution on, or ring cleavage of, the phenols.
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Soil and Crop Sciences Department, Texas A&M University, College Station, Texas 77843.