Spatiotemporal dynamics of FERONIA reveal alternative endocytic pathways in response to flg22 elicitor stimuli

The plant receptor-like kinase FERONIA (FER) functions in the response to multiple extracellular signals, thereby regulating diverse cellular processes, such as polarized cell growth, hormone signaling and responses to pathogens. Here, we reported that in Arabidopsis thaliana, flagellin peptide flg22 stimulus significantly promoted the lateral mobility and dissociation of FER from the plasma membrane by inducing the association of FER with membrane microdomain components. FER underwent constitutive endocytosis and recycling in a brefeldin A (BFA)-sensitive manner via a clathrin-mediated pathway. Following flg22 elicitation, FER localized to bona fide endosomes via two distinct endocytic routes, showing differential sensitivity to BFA. These results at the single-particle level confirm that FER acts as an essential regulator during flg22 perception and immune activation, thus broadening our understanding of location-specific protein dynamics and membrane trafficking in receptor/receptor kinase signaling.