Open AccessEffect of fluorophenylalanine on indole-3-acetic acid oxidation in Avena coleoptiles
Author(s) -
Andrew B. Maksymowych,
Joseph A. J. Orkwiszewski
Publication year - 2014
Publication title -
acta societatis botanicorum poloniae
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.297
H-Index - 29
eISSN - 2083-9480
pISSN - 0001-6977
DOI - 10.5586/asbp.1992.034
Subject(s) - coleoptile , avena , incubation , oxidizing agent , auxin , etiolation , chemistry , elongation , biochemistry , phenylalanine , biology , botany , amino acid , enzyme , organic chemistry , materials science , ultimate tensile strength , gene , metallurgy
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 µM) 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