Submitted to: Plant Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/7/2011
Publication Date: 7/12/2011
Citation: Guo, Y., Ni, J., Denver, R., Wang, X., Clark, S.E. 2011. Mechanisms of molecular mimicry of plant CLE peptide ligands by the parasitic nematode Globodera rostochiensis. Plant Physiology. 157:476-484. DOI: 10.1104/PP.2011-180554. Interpretive Summary: Nematodes that parasitize plant roots cause huge economic losses. The CLE protein family, once thought to be plant-specific, was recently identified in plant-parasitic cyst nematodes. This discovery led to the hypothesis that cyst nematodes may use CLE proteins for their parasitic benefit. In plants CLE precursor proteins are processed to become active CLE peptides that play diverse roles in plant development. In this study, we showed that the GrCLE1 precursor protein, encoded by the potato cyst nematode (Globodera rostochiensis), is correctly processed by the potato root extract. The processed GrCLE1 peptides were found to bind directly to several plant CLE receptors. These results clearly indicated that nematode CLEs can become functional CLE peptides once they are released into host roots by the nematode. We also showed that host and non-host plants differ in the ability to process GrCLE1 with host species containing more processing activity. This new knowledge may suggest a potential target to block nematode infection.
Technical 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. The CLE family of receptor ligands, thought to be plant-specific, was subsequently identified in plant-parasitic nematodes as well, leading to the hypothesis that the parasites use the CLE proteins to alter root development. In plants, CLE precursor proteins undergo proteolytic maturation to release active CLE peptides which act as receptor ligands to regulate differentiation of stem cells at the shoot and root meristem, in the vascular system and during nodulation. Here we present evidence that the GrCLE1 protein encoded by potato cyst nematode (PCN) Globodera rostochiensis is correctly processed by plant CLE processing activities. The processed GrCLE1 peptides bind directly to several plant CLE receptors and can alter plant root development in both host and non-host species. We also show that host and non-host plants differ in the ability to process the GrCLE1 precursor, with host species containing more robust processing activity, suggesting a possible mechanism of G. rostochiensis host range determination and providing a potential target to block nematode parasitism.