title: Analysis of putative apoplastic effectors from the nematode, Globodera rostochiensis, and identification of an expansin-like protein that can induce and suppress host defenses.
abstract: The potato cyst nematode, Globodera rostochiensis, is an important pest of potato. Like other pathogens, plant parasitic nematodes are presumed to employ effector proteins, secreted into the apoplast as well as the host cytoplasm, to alter plant cellular functions and successfully infect their hosts. We have generated a library of ORFs encoding putative G. rostochiensis putative apoplastic effectors in vectors for expression in planta. These clones were assessed for morphological and developmental effects on plants as well as their ability to induce or suppress plant defenses. Several CLAVATA3/ESR-like proteins induced developmental phenotypes, whereas predicted cell wall-modifying proteins induced necrosis and chlorosis, consistent with roles in cell fate alteration and tissue invasion, respectively. When directed to the apoplast with a signal peptide, two effectors, an ubiquitin extension protein (GrUBCEP12) and an expansin-like protein (GrEXPB2), suppressed defense responses including NB-LRR signaling induced in the cytoplasm. GrEXPB2 also elicited defense response in species- and sequence-specific manner. Our results are consistent with the scenario whereby potato cyst nematodes secrete effectors that modulate host cell fate and metabolism as well as modifying host cell walls. Furthermore, we show a novel role for an apoplastic expansin-like protein in suppressing intra-cellular defense responses.
authors.affiliation: Département de Biologie, Université de Sherbrooke, 2500 Boulevard de l'Université Sherbrooke, Sherbrooke, Québec, Canada; Horticulture R & D Centre Agriculture and Agri-Food Canada, 430 Boulevard Gouin, St-Jean-sur-Richelieu, Québec, Canada.
authors.forename: Shawkat
authors.initials: S
authors.lastname: Ali
authors.affiliation: Département de Biologie, Université de Sherbrooke, 2500 Boulevard de l'Université Sherbrooke, Sherbrooke, Québec, Canada.
authors.forename: Maxime
authors.initials: M
authors.lastname: Magne
authors.affiliation: Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853, United States of America.
authors.forename: Shiyan
authors.initials: S
authors.lastname: Chen
authors.affiliation: Département de Biologie, Université de Sherbrooke, 2500 Boulevard de l'Université Sherbrooke, Sherbrooke, Québec, Canada.
authors.forename: Olivier
authors.initials: O
authors.lastname: Côté
authors.affiliation: Agricultural Institute of Slovenia, Plant Protection Department, Hacquetova ulica 17, SI-1000 Ljubljana, Slovenia.
authors.forename: Barbara Gerič
authors.initials: BG
authors.lastname: Stare
authors.affiliation: Département de Biologie, Université de Sherbrooke, 2500 Boulevard de l'Université Sherbrooke, Sherbrooke, Québec, Canada.
authors.forename: Natasa
authors.initials: N
authors.lastname: Obradovic
authors.affiliation: Département de Biologie, Université de Sherbrooke, 2500 Boulevard de l'Université Sherbrooke, Sherbrooke, Québec, Canada.
authors.forename: Lubna
authors.initials: L
authors.lastname: Jamshaid
authors.affiliation: Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853, United States of America; Robert W. Holley Center for Agriculture and Health, US Department of Agriculture, Agricultural Research Service, Ithaca, New York 14853, United States of America.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Wang
authors.affiliation: Horticulture R & D Centre Agriculture and Agri-Food Canada, 430 Boulevard Gouin, St-Jean-sur-Richelieu, Québec, Canada.
authors.forename: Guy
authors.initials: G
authors.lastname: Bélair
authors.affiliation: Département de Biologie, Université de Sherbrooke, 2500 Boulevard de l'Université Sherbrooke, Sherbrooke, Québec, Canada.
authors.forename: Peter
authors.initials: P
authors.lastname: Moffett
mesh_terms: D000818:Animals; D005786:Gene Expression Regulation / Q000502:physiology*; D015801:Helminth Proteins / Q000096:biosynthesis* / Q000235:genetics; D054884:Host-Pathogen Interactions / Q000502:physiology*; D009348:Nematoda / Q000502:physiology*; D010935:Plant Diseases / Q000469:parasitology*; D011198:Solanum tuberosum / Q000469:parasitology*
chemical_list: D015801:Helminth Proteins