title: Nematode Parasitism Genes.
abstract: The ability of nematodes to live on plant hosts involves multiple parasitism genes. The most pronounced morphological adaptations of nematodes for plant parasitism include a hollow, protrusible stylet (feeding spear) connected to three enlarged esophageal gland cells that express products that are secreted into plant tissues through the stylet. Reverse genetic and expressed sequence tag (EST) approaches are being used to discover the parasitism genes expressed in nematode esophageal gland cells. Some genes cloned from root-knot (Meloidogyne spp.) and cyst (Heterodera and Globodera spp.) nematodes have homologues reported in genomic analyses of Caenorhabditis elegans and animal-parasitic nematodes. To date, however, the candidate parasitism genes endogenous to the esophageal glands of plant nematodes (such as the ß-1,4-endoglucanases) have their greatest similarity to microbial genes, prompting speculation that genes for plant parasitism by nematodes may have been acquired by horizontal gene transfer.
authors.affiliation: Department of Plant Pathology, North Carolina State University, Campus Box 7616, Raleigh, North Carolina 27695; e-mail: eric_davis@ncsu.edu.
authors.forename: Eric L
authors.initials: EL
authors.lastname: Davis
authors.affiliation: Department of Plant Pathology, University of Georgia, 2309 Miller Plant Science Building, Athens, Georgia 30602-7274; e-mail: hussey@uga.cc.uga.edu.
authors.forename: Richard S
authors.initials: RS
authors.lastname: Hussey
authors.affiliation: Department of Plant Pathology, Iowa State University, 351 Bessey Hall, Ames, Iowa 50011; e-mail: tbaum@iastate.edu.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Baum
authors.affiliation: Department of Nematology, Wageningen University and Research Centre, Binnenhaven 10, PD Wageningen, 6709 The Netherlands; e-mail: Jaap.Bakker@MEDEW.NEMA.WAU.NL ; Arjen.Schots@LMA.NEMA.WAU.NL.
authors.forename: Jaap
authors.initials: J
authors.lastname: Bakker
authors.affiliation: Department of Nematology, Wageningen University and Research Centre, Binnenhaven 10, PD Wageningen, 6709 The Netherlands; e-mail: Jaap.Bakker@MEDEW.NEMA.WAU.NL ; Arjen.Schots@LMA.NEMA.WAU.NL.
authors.forename: Arjen
authors.initials: A
authors.lastname: Schots
authors.affiliation: Laboratoire de Biologie des Invertebres, Institut National de la Recherche Agronomique, 123 Boulevarde Francis Meilland, Cedex Antibes, 06600 France; e-mail: rosso@antibes.inra.fr ; abad@antibes.inra.fr.
authors.forename: Marie-Noëlle
authors.initials: MN
authors.lastname: Rosso
authors.affiliation: Laboratoire de Biologie des Invertebres, Institut National de la Recherche Agronomique, 123 Boulevarde Francis Meilland, Cedex Antibes, 06600 France; e-mail: rosso@antibes.inra.fr ; abad@antibes.inra.fr.
authors.forename: Pierre
authors.initials: P
authors.lastname: Abad