Auxins action on Glycine max secretory phospholipase A2 is mediated by the interfacial properties imposed by the phytohormones

•Auxins self penetrate phospholipid monolayers (membrane model system).•Auxins become stabilized at the interface in presence of phospholipids.•Auxins stimulate the activity of sPLA2 independently of aggregate substrate organization.•Auxins stimulate the activity of sPLA2 regardless of enzyme source (plant or animal).•The effect of auxins on sPLA2 activity is at the membrane interface level.