Phenylalanine Ammonia‐Lyase Activity in Soybean Roots Extract Measured by Reverse‐Phase High Performance Liquid Chromatography

The high performance liquid chromatography (HPLC) technique was applied to measure phenylalanine ammonia‐lyase (PAL, EC 4.3.1.5) activity in soybean (Glycine max L. Merril cv. BR16) roots. t‐Cinnamate, the catalytic product of the PAL reaction was quantified at 275nm by isocratic elution with methanol: water through an ODS(M) column. Comparative experiments were carried out with 1.0 mM ferulic acid, an inducer of PAL activity. The results suggest that liquid chromatography is a rapid and sensitive method to analyze PAL activity in non‐purified extract.