Quantification of Salicylic Acid (SA) and SA-glucosides in Arabidopsis thaliana

Homeostasis between the cytoplasmic plant hormone salicylic acid (SA) and its' inactive, vacuolar storage forms, SA-2-O-β-D-glucoside (SAG) and SA-β-D-Glucose Ester (SGE), regulates the fine-tuning of defense responses to biotrophic pathogens in Arabidopsis thaliana. This protocol describes a simplified, optimized procedure to extract and quantify free SA and total hydrolyzable SA in plant tissues using a classical HPLC-based method.