Inhibition of selected plant systems by stereoisomers of chloramphenicol

Abstract The stereospecificity of chloramphenicol isomers on the inhibition of several plant systems was investigated. l - Threo , d - erythro , l - erythro and the antibiotic d - threo -chloramphenicol were effective inhibitors of auxin-induced elongation, 14 C-leucine uptake and 14 C-leucine incorporation into the protein fraction of coleoptiles from Avena sativa and Triticum vulgare . The isomers also inhibited Avena coleoptile uptake of 14 C-α-aminoisobutyric acid and the de novo synthesis of α-amylase by aleurone layers from Hordeum vulgare seeds. All four compounds inhibited these processes to about the same extent and over a similar high concentration range (5 × 10 −4 to 5 × 10 −3 M). Bioassay of extracts from Avena coleoptiles treated with the non-antibiotic isomers revealed no tissue conversion into d - threo -chloramphenicol.