P-222 - Investigating the dual function of PROSCOOP peptides as stress signals and antimicrobial peptides

Endogenous peptides are crucial for effective cell-to-cell signaling in plant immune responses. In response to biotic and abiotic stresses, Brassicales secrete SERINE RICH ENDOGENOUS PEPTIDES (SCOOPs) that are recognized by the receptor kinase MALE DISCOVERER 1-INTERACTING RECEPTOR-LIKE KINASE 2 (MIK2). With 50 members in Arabidopsis thaliana, the SCOOP family is one of the largest known families of signaling peptides and shows remarkably high length- and sequence-diversity. How SCOOPs are all recognized by a single receptor and yet control different downstream biological processes remains unresolved. SCOOPs are initially produced as pro-peptides (PROSCOOPs) and require proteolytic processing to become active. To investigate how these peptides are processed and recognized, transient expression systems are being developed in yeast and tobacco to identify the precise PROSCOOP maturation. Additionally, we are exploring the potential role of C-terminal regions of PROSCOOPs in recruiting specific signaling components to fine-tune responses. According to in vitro assays with a variety of plant pathogens, PROSCOOPs may also have direct antimicrobial activity, constituting an additional SCOOP-mediated layer of defense and providing evolutionary insights into the origin of this peptide family. This project advances our understanding of this recently identified large family of stress-responsive peptides and will assist the development of novel solutions for sustainable agriculture.