%0 Journal Article %T Effect of fluorophenylalanine on indole-3-acetic acid oxidation in Avena coleoptiles %A Andrew B. Maksymowych %A Joseph A.J. Orkwiszewski %J Acta Societatis Botanicorum Poloniae %D 1992 %I Polish Botanical Society %R 10.5586/asbp.1992.034 %X Effects of the amino acid analog D,L-p-fluorophenylalanine on auxin oxidizing activity from Avena saliva cv. Clintford have been examined. Incubation of etiolated Avena coleoptile apices with D,L-p-fluorophenylalanine, previously reported to promote elongation and depress phenolic metabolism, lowers auxin oxidizing activity. Temperature and pH profiles demonstrated that depression of oxidizing activity by D,L-p-fluorophenylalanine occurs over a relatively wide range. Incubation of coleoptiles in media containing L-phenylalanine alone or L-phenylalanine combined with D,L-p-fluorophenylalanine result in oxidizing activities which are, respectively, slightly higher than or restored to control levels. Thus, dark incubation of coleoptiles with D,L-p-fluorophenylalanine results in auxin oxidizing activity which differs from that of control and other treatment groups. Oxidizing activity from D,L-p-fluorophenylalanine pretreated coleoptiles has a Michaelis constant (70 ¦ÌM) and a maximum velocity (0.200) which are consistently lower than the control constants. These findings provide further clarification of the effects of D,L-p-fluorophenylalanine, on coleoptile elongation and auxin oxidizing activity in etiolated Avena coleoptiles. %K auxin oxidation %K Avena coleoptile %K fluorophenylalanine %K phenolic metabolism %U http://pbsociety.org.pl/journals/index.php/asbp/article/view/1187