title: Transcriptome of Aphanomyces euteiches: new oomycete putative pathogenicity factors and metabolic pathways.
abstract: Aphanomyces euteiches is an oomycete pathogen that causes seedling blight and root rot of legumes, such as alfalfa and pea. The genus Aphanomyces is phylogenically distinct from well-studied oomycetes such as Phytophthora sp., and contains species pathogenic on plants and aquatic animals. To provide the first foray into gene diversity of A. euteiches, two cDNA libraries were constructed using mRNA extracted from mycelium grown in an artificial liquid medium or in contact to plant roots. A unigene set of 7,977 sequences was obtained from 18,864 high-quality expressed sequenced tags (ESTs) and characterized for potential functions. Comparisons with oomycete proteomes revealed major differences between the gene content of A. euteiches and those of Phytophthora species, leading to the identification of biosynthetic pathways absent in Phytophthora, of new putative pathogenicity genes and of expansion of gene families encoding extracellular proteins, notably different classes of proteases. Among the genes specific of A. euteiches are members of a new family of extracellular proteins putatively involved in adhesion, containing up to four protein domains similar to fungal cellulose binding domains. Comparison of A. euteiches sequences with proteomes of fully sequenced eukaryotic pathogens, including fungi, apicomplexa and trypanosomatids, allowed the identification of A. euteiches genes with close orthologs in these microorganisms but absent in other oomycetes sequenced so far, notably transporters and non-ribosomal peptide synthetases, and suggests the presence of a defense mechanism against oxidative stress which was initially characterized in the pathogenic trypanosomatids.
authors.affiliation: UMR 5546 Centre National de la Recherche Scientifique (CNRS), Université Paul Sabatier Toulouse III, Université de Toulouse, Pôle de Biotechnologie Végétale, Castanet-Tolosan, France. gaulin@scsv.ups-tlse.fr
authors.forename: Elodie
authors.initials: E
authors.lastname: Gaulin
authors.forename: Mohammed-Amine
authors.initials: MA
authors.lastname: Madoui
authors.forename: Arnaud
authors.initials: A
authors.lastname: Bottin
authors.forename: Christophe
authors.initials: C
authors.lastname: Jacquet
authors.forename: Catherine
authors.initials: C
authors.lastname: Mathé
authors.forename: Arnaud
authors.initials: A
authors.lastname: Couloux
authors.forename: Patrick
authors.initials: P
authors.lastname: Wincker
authors.forename: Bernard
authors.initials: B
authors.lastname: Dumas
mesh_terms: D044744:Aphanomyces / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D020224:Expressed Sequence Tags; D020869:Gene Expression Profiling; D015723:Gene Library; D005800:Genes, Fungal; D008565:Membrane Proteins / Q000378:metabolism; D053858:Metabolic Networks and Pathways; D009868:Oomycetes / Q000378:metabolism*; D010838:Phytophthora / Q000378:metabolism; D018517:Plant Roots / Q000254:growth & development / Q000378:metabolism; D020543:Proteome / Q000032:analysis*; D037521:Virulence Factors / Q000378:metabolism*
chemical_list: D008565:Membrane Proteins; D020543:Proteome; D037521:Virulence Factors