Submitted to: Molecular Plant-Microbe Interactions
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/11/2009
Publication Date: 6/15/2009
Citation: Lu, S., Chen, S., Wang, J., Yu, H., Chronis, D., Mitchum, M.G., Wang, X. 2009. Structural and functional diversity of CLAVATA3/ESR (CLE)-like genes from the potato cyst nematode Globodera rostochiensis. Molecular Plant-Microbe Interactions. 22:1128-1142.
Interpretive Summary: The potato cyst nematode Globodera rostochiensis (also known as the golden nematode) is a quarantined pest that represents one of the most devastating pests of potatoes worldwide. In order to successfully parasitize host roots, the nematode secretes proteins originated from its esophageal gland cells to transform plant cells into a specialized site for the nematode to feed. Understanding the function of nematode parasitism genes encoding these gland secretions will be very useful for developing novel nematode control strategies. This paper describes the isolation and functional characterization of five new genes from G. rostochiensis that have sequence similarity to plant CLE genes. This study has discovered that nematode produced CLE proteins function similarly to plant CLEs and suggested that ligand mimicry of plant CLE proteins may be an important mechanism for plant parasitism by G. rostochiensis. Knowledge developed from this study may identify new targets for generating novel nematode resistance in potato.
Technical Abstract: Plant CLAVATA3/ESR-related (CLE) peptides have diverse roles in plant growth and development. Here, we report the isolation and functional characterization of five new CLE genes from the potato cyst nematode Globodera rostochiensis. Unlike typical plant CLEs that contain a single CLE motif, four of the five Gr-CLE genes encode CLE proteins with multiple CLE motifs. These Gr-CLEs were found to be specifically expressed within the dorsal esophageal gland cell of nematode parasitic stages, suggesting a role for their encoded proteins in plant parasitism. Overexpression of Gr-CLEs in Arabidopsis mimicked overexpression of plant CLEs and Gr-CLE proteins could rescue the Arabidopsis clv3-2 mutant phenotype when expressed within meristems. A short root phenotype was observed when synthetic GrCLE peptides were exogenously applied to roots of Arabidopsis or potato similar to the overexpression of Gr-CLEs in Arabidopsis and potato hairy roots. These results reveal that G. rostochiensis CLEs with either single or multiple CLE motifs function similarly to plant CLEs and that CLE signaling components are conserved in both Arabidopsis and potato roots. Furthermore, our results provide evidence to suggest that the evolution of multiple CLE motifs may be an important mechanism for generating functional diversity in nematode CLE proteins to facilitate parasitism.