Submitted to: Journal of Nematology
Publication Type: Abstract Only
Publication Acceptance Date: 4/6/2006
Publication Date: 6/18/2006
Citation: Lu, S., Tian, D., Deng, X., Thurston, D., Wang, X. 2006. Parasitism genes identified in the potato cyst nematode, globodera rostochiensis, using a comparative genomic approach [abstract]. Journal of Nematology. 38(2):280.
Technical Abstract: Stylet secretions are encoded by parasitism genes expressed in the esophageal gland cells of plant-parasitic nematodes. These are the primary signals that facilitate nematode migration in host roots and control the formation of the elaborate feeding cells necessary for the development and reproduction of the nematode. Cyst nematodes of genera Heterodera (e.g. the soybean cyst nematode, SCN, H. glycines) and Globodera (e.g. the potato cyst nematode, PCN, G. rostochiensis) are devastating pests of agriculturally important crops in the US. Both SCN and PCN induce syncytia in their host roots for feeding. BLAST searches using fifty parasitism protein sequences of SCN against approximately 6,000 PCN ESTs have led to the discovery of ten new putative parasitism genes in PCN. Seven of them were further cloned including CLE-like gene (GrCLE1), venom allergen-like gene (GrVAP1), ubiquitin extension gene (GrUBI1), SKP1-like gene (GrSKP1), chorismate mutase gene (GrCM1), and two pioneer genes (Gr4E02 and Gr33E05) corresponding to 4E02 and 33E05 of SCN. Southern blot analysis confirmed the presence of these genes in PCN. GrCLE1, GrCM1 and GrUBI1 were found to be expressed exclusively within esophageal gland cells of the nematode using mRNA in-situ hybridization analysis. In addition, all seven genes except Gr4E02 were also expressed in parasitic stages, suggesting an important role in nematode parasitism of hosts. Further identification and functional studies of PCN parasitism genes will lead to a better understanding of the PCN-potato interaction and may provide targets for developing novel strategies to engineer PCN resistance in potato.