Identification of new Dickeya dadantii virulence factors secreted by the type 2 secretion system
Résumé
Dickeya are plant pathogenic bacteria able to provoke disease on a wide range of plants. A type 2 secretion system named Out is necessary for bacterial virulence. Its study in D. dadantii showed that it secretes a wide range of pectinolytic enzymes. However, the full repertoire of exoproteins it can secrete has not been identified. No secretion signal present on the protein allows the identification of substrates of a type 2 secretion system. To identify new Out substrates, we analyzed D. dadantii transcriptome data obtained in plant infection condition and searched for genes strongly induced encoding a protein with a signal sequence. We identified four new Out-secreted proteins: the expansin YoaJ, VirK and two proteins of the DUF 4879 family, SvfA and SvfB. We showed that SvfA and SvfB are required for full virulence of D. dadantii and showed that Svf proteins are present with a variable number of copies, up to three in D. fanghzongdai, in other Pectobacteriaceae. This work opens the way to the study of the role in virulence of non-pectinolytic proteins secreted by the Out pathway in Pectobacteriaceae.
Domaines
Sciences du Vivant [q-bio]Origine | Fichiers produits par l'(les) auteur(s) |
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