Abstract
Phytoalexins are antimicrobial substance synthesized in plants upon pathogen infection. Pisatin (Pisum sativum phytoalexin) is the major phytoalexin in pea, while it is also a valuable indicator of plant defense response. Pisatin can be quantitated in various methods from classical organic chemistry to Mass-spectrometry analysis. Here we describe a procedure with high reproducibility and simplicity that can easily handle large numbers of treatments. The method only requires a spectrophotometer as laboratory equipment, does not require any special analytical instruments (e.g., HPLC, mass spectrometers, etc.) to measure the phytoalexin molecule quantitatively, i.e., most scientific laboratories can perform the experiment.