title: The cyst nematode effector protein 10A07 targets and recruits host posttranslational machinery to mediate its nuclear trafficking and to promote parasitism in Arabidopsis.
abstract: Plant-parasitic cyst nematodes synthesize and secrete effector proteins that are essential for parasitism. One such protein is the 10A07 effector from the sugar beet cyst nematode, Heterodera schachtii, which is exclusively expressed in the nematode dorsal gland cell during all nematode parasitic stages. Overexpression of H. schachtii 10A07 in Arabidopsis thaliana produced a hypersusceptible phenotype in response to H. schachtii infection along with developmental changes reminiscent of auxin effects. The 10A07 protein physically associates with a plant kinase and the IAA16 transcription factor in the cytoplasm and nucleus, respectively. The interacting plant kinase (IPK) phosphorylates 10A07 at Ser-144 and Ser-231 and mediates its trafficking from the cytoplasm to the nucleus. Translocation to the nucleus is phosphorylation dependent since substitution of Ser-144 and Ser-231 by alanine resulted in exclusive cytoplasmic accumulation of 10A07. IPK and IAA16 are highly upregulated in the nematode-induced syncytium (feeding cells), and deliberate manipulations of their expression significantly alter plant susceptibility to H. schachtii in an additive fashion. An inactive variant of IPK functioned antagonistically to the wild-type IPK and caused a dominant-negative phenotype of reduced plant susceptibility. Thus, exploitation of host processes to the advantage of the parasites is one mechanism by which cyst nematodes promote parasitism of host plants.
authors.affiliation: Department of Plant Sciences, University of Tennessee, Knoxville, Tennessee 37996 thewezi@utk.edu tbaum@iastate.edu.
authors.forename: Tarek
authors.initials: T
authors.lastname: Hewezi
authors.affiliation: Department of Plant Pathology, Iowa State University, Ames, Iowa 50011.
authors.forename: Parijat S
authors.initials: PS
authors.lastname: Juvale
authors.affiliation: Department of Plant Sciences, University of Tennessee, Knoxville, Tennessee 37996.
authors.forename: Sarbottam
authors.initials: S
authors.lastname: Piya
authors.affiliation: Department of Plant Pathology, Iowa State University, Ames, Iowa 50011.
authors.forename: Tom R
authors.initials: TR
authors.lastname: Maier
authors.affiliation: Department of Plant Sciences, University of Tennessee, Knoxville, Tennessee 37996.
authors.forename: Aditi
authors.initials: A
authors.lastname: Rambani
authors.affiliation: Department of Plant Sciences, University of Tennessee, Knoxville, Tennessee 37996.
authors.forename: J Hollis
authors.initials: JH
authors.lastname: Rice
authors.affiliation: Division of Plant Sciences and Bond Life Sciences Center, University of Missouri, Columbia, Missouri 65211.
authors.forename: Melissa G
authors.initials: MG
authors.lastname: Mitchum
authors.affiliation: North Carolina State University, Raleigh, North Carolina 27695.
authors.forename: Eric L
authors.initials: EL
authors.lastname: Davis
authors.affiliation: Department of Plant Pathology, University of Georgia, Athens, Georgia 30602.
authors.forename: Richard S
authors.initials: RS
authors.lastname: Hussey
authors.affiliation: Department of Plant Pathology, Iowa State University, Ames, Iowa 50011 thewezi@utk.edu tbaum@iastate.edu.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Baum
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017360:Arabidopsis / Q000378:metabolism* / Q000469:parasitology*; D029681:Arabidopsis Proteins / Q000378:metabolism; D027461:Beta vulgaris / Q000469:parasitology; D002467:Cell Nucleus / Q000378:metabolism*; D006790:Host-Parasite Interactions; D007210:Indoleacetic Acids / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D019913:Nuclear Localization Signals; D010766:Phosphorylation; D010768:Phosphoserine / Q000378:metabolism; D010935:Plant Diseases / Q000469:parasitology; D011494:Protein Kinases / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D021381:Protein Transport; D015800:Protozoan Proteins / Q000378:metabolism*; D014431:Tylenchoidea / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D019913:Nuclear Localization Signals; D015800:Protozoan Proteins; D010768:Phosphoserine; D011494:Protein Kinases