PEROXIDASE-H2O2 CATALYZED INCORPORATION OF AUXIN DERIVATIVES INTO SOLUBLE-RNA

Derivatives from 3-indolyl(2-14C) acetic acid and 2,4-dichlorophenoxy (ring UL[uniformly labeled]-14C) acetic acid were bound to sRNA upon reaction with a H2O2-horseradish peroxidase system. No radioactivity was incorporated from 3-indolyl-(1-14C) acetic acid or from 2,4-dichlorophenoxy(2-14C) acetic acid indicating decarboxylation of the IAA and loss of the acetate moiety by the phenoxyacetic acid upon activation or binding. These results demonstrate that H2O2-oxidized peroxidase can produce reactive auxin derivatives that bind covalently to cellular nucleophiles. This activation may be required to produce the ultimate phytohormone in vivo.