Mechanisms of Molecular Mimicry of Plant CLE Peptide Ligands by the Parasitic Nematode Globodera rostochiensis

Nematodes that parasitize plant roots cause huge economic losses and have few mechanisms for control. Many parasitic nematodes infect plants by reprogramming root development to drive the formation of feeding structures. How nematodes take control of plant development is largely unknown. Here we identify two host factors involved in the function of a receptor ligand mimic, GrCLE1, secreted by the potato cyst nematode (PCN) Globodera rostochiensis. GrCLE1 is correctly processed to an active form by host plant proteases. Processed GrCLE1 peptides bind directly to the plant CLE receptors CLV2, BAM1 and BAM2. Involvement of these receptors in the ligand mimicking process is also supported by the facts that the ability of GrCLE1 peptides to alter plant root development in Arabidopsis is dependent on these receptors. Critically, we also demonstrate that GrCLE1 maturation can be entirely carried out by plant factors and that the availability of CLE processing activity may be essential for successful ligand mimicry.