Abstract
The Rapid Alkalinization Factor (RALF) is a plant hormone peptide that inhibits proton transport causing alkalinization of the extracellular media. To detect the alkalinization response elicited by RALF peptides in root cells, Arabidopsis seedlings are carefully transferred to a gel containing the pH-sensitive indicator bromocresol purple, treated with the peptide and photographed after 30 min. Herein the protocol is optimized for evaluation of exogenous treatment, described in detail and expected results are presented.