Molecular mimicry of plant CLE peptide ligands by a parasitic nematode

 Yongfeng Guo¹* and Steven Clark²

1. Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, Shandong 266101
2. Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109 USA
* Corresponding Author：Tel: (+86532) 6671 5256; Fax: (+86532) 8870 2056; E-mail: yongfeng.guo@gmail.com

Abstract
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 characterize a ligand mimicry mechanism of a nematode protein, CLE1, 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.

Key words: GrCLE1; CLV receptors; root growth; ligand mimicry; Globodera rostochiensis; proteolytic processing