A Simple Inexpensive Method for the Measurement of Indoleacetamide Hydrolase Activity

Abstract

Indole-3-acetic acid (IAA) a phytohormon of auxin type is synthesized by different ways in plants and some bacteria (Agrobacteria, Pseudomonas and some others). The enzyme indolylacetamide hydrolase transforms indolylacetamide to IAA mainly in bacteria. However, recently published data showed that some plants can also hydrolyze indolylacetamide into IAA. In order to elucidate the role of indolylacetamide as an auxin precursor in plants and bacteria, productive method of determination of the activity of indoleacetamide hydrolase is necessary. The simple, inexpensive and productive method for the measurement of indoleacetamide hydrolase activity was elaborated based on significant difference between IAAM and IAA in color developed with Salkovski’ reagent. The light absorbance increased during conversion of IAAM to IAA by protein extracts from some plant cells and this increase may be used for quantitative estimation of indoleacetamide hydrolase activity. The method is suitable for fast discovery of indoleacetamide hydrolase activity before planning more complicated analyses and for the analysis of many probes at a short time in physiological and biochemical experiments. A detailed protocol for determination of indoleacetamide hydrolase activity by the elaborated method is described.