Moss secreted peptidome - Salicylic acid influences the protease activity and posttranslation modifications of the secreted peptides in the moss Physcomitrella patens

Plant secretome comprise dozens of secreted proteins and peptide hormones. However, little is known about peptide composition of plant secretome as well as proteases responsible for peptide pools generation. While the majority of studies focuses on the target detection and characterization of specific plant peptide hormones, we performed a comprehensive analysis of the whole extracellular peptidome, using moss Physcomitrella patens as a model object. We identified hundreds of modified and unmodified endogenous peptides originated from functional and non-functional protein precursors. Plant proteases responsible for shaping the pool of endogenous peptides were predicted. We showed that salicylic acid (SA) induces peptide production in the secretome.