title: Pep-13, a plant defense-inducing pathogen-associated pattern from Phytophthora transglutaminases.
abstract: Innate immunity, an ancient form of defense against microbial infection, is well described for animals and is also suggested to be important for plants. Discrimination from self is achieved through receptors that recognize pathogen-associated molecular patterns (PAMPs) not found in the host. PAMPs are evolutionarily conserved structures which are functionally important and, thus, not subject to frequent mutation. Here we report that the previously described peptide elicitor of defense responses in parsley, Pep-13, constitutes a surface-exposed fragment within a novel calcium-dependent cell wall transglutaminase (TGase) from Phytophthora sojae. TGase transcripts and TGase activity are detectable in all Phytophthora species analyzed, among which are some of the most destructive plant pathogens. Mutational analysis within Pep-13 identified the same amino acids indispensable for both TGase and defense-eliciting activity. Pep-13, conserved among Phytophthora TGases, activates defense in parsley and potato, suggesting its function as a genus-specific recognition determinant for the activation of plant defense in host and non-host plants. In summary, plants may recognize PAMPs with characteristics resembling those known to trigger innate immune responses in animals.
authors.affiliation: Abteilung für Stress, Institut für Pflanzenbiochemie, Weinberg 3, D-06120 Halle/Saale, Germany.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Brunner
authors.forename: Sabine
authors.initials: S
authors.lastname: Rosahl
authors.forename: Justin
authors.initials: J
authors.lastname: Lee
authors.forename: Jason J
authors.initials: JJ
authors.lastname: Rudd
authors.forename: Carola
authors.initials: C
authors.lastname: Geiler
authors.forename: Sakari
authors.initials: S
authors.lastname: Kauppinen
authors.forename: Grethe
authors.initials: G
authors.lastname: Rasmussen
authors.forename: Dierk
authors.initials: D
authors.lastname: Scheel
authors.forename: Thorsten
authors.initials: T
authors.lastname: Nürnberger
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D015152:Blotting, Northern; D017124:Conserved Sequence; D004252:DNA Mutational Analysis; D004305:Dose-Response Relationship, Drug; D008969:Molecular Sequence Data; D009154:Mutation; D010838:Phytophthora / Q000201:enzymology*; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D011198:Solanum tuberosum / Q000378:metabolism; D013997:Time Factors; D011503:Transglutaminases / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D012333:RNA, Messenger; D011994:Recombinant Proteins; D011503:Transglutaminases