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Transcriptome of Aphanomyces euteiches: new oomycete putative pathogenicity factors and metabolic pathways.

Gaulin E, Madoui MA, Bottin A, Jacquet C, Mathé C, Couloux A, Wincker P, Dumas B - PLoS ONE (2008)

Bottom Line: 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.

View Article: PubMed Central - PubMed

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

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.

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Identification of conserved amino acid residues at the N-terminal extremities of P. infestans and A. euteiches CRN sequences.A, multiple alignment of A. euteiches like CRNs and P. infestans CRNs (CRN1, CRN5, CRN11, CRN14) showing the highest homology to A. euteiches sequences. B, consensus sequence pattern calculated using Weblogo showing the most conserved amino acid residues.
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pone-0001723-g006: Identification of conserved amino acid residues at the N-terminal extremities of P. infestans and A. euteiches CRN sequences.A, multiple alignment of A. euteiches like CRNs and P. infestans CRNs (CRN1, CRN5, CRN11, CRN14) showing the highest homology to A. euteiches sequences. B, consensus sequence pattern calculated using Weblogo showing the most conserved amino acid residues.

Mentions: A distinct class of putative cytoplasmic effectors is the Crinkling and Necrosis (CRN) family first described in P. infestans [48]. While Phytophthora CRNs lack an RxLR motif, some H. parasitica CRNs show an RxRL sequence overlapping another conserved motif LxFLAK [24]. Several sequences showing high similarity with Phytophthora CRN were detected in A. euteiches. The largest groups of CRNs showed strong similarity to P. infestans CRN5 (14 unigenes) or CRN13 (9 unigenes). Interestingly, the conserved LxLFLAK sequence was not present in A. euteiches genes, but a closely related motif, F/LxLYLALK, was detected (Figure 6). This is the first time that CRN genes are found in an organism distinct from Peronosporales suggesting that this class of effectors plays an important role in oomycete pathogenicity.


Transcriptome of Aphanomyces euteiches: new oomycete putative pathogenicity factors and metabolic pathways.

Gaulin E, Madoui MA, Bottin A, Jacquet C, Mathé C, Couloux A, Wincker P, Dumas B - PLoS ONE (2008)

Identification of conserved amino acid residues at the N-terminal extremities of P. infestans and A. euteiches CRN sequences.A, multiple alignment of A. euteiches like CRNs and P. infestans CRNs (CRN1, CRN5, CRN11, CRN14) showing the highest homology to A. euteiches sequences. B, consensus sequence pattern calculated using Weblogo showing the most conserved amino acid residues.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2248709&req=5

pone-0001723-g006: Identification of conserved amino acid residues at the N-terminal extremities of P. infestans and A. euteiches CRN sequences.A, multiple alignment of A. euteiches like CRNs and P. infestans CRNs (CRN1, CRN5, CRN11, CRN14) showing the highest homology to A. euteiches sequences. B, consensus sequence pattern calculated using Weblogo showing the most conserved amino acid residues.
Mentions: A distinct class of putative cytoplasmic effectors is the Crinkling and Necrosis (CRN) family first described in P. infestans [48]. While Phytophthora CRNs lack an RxLR motif, some H. parasitica CRNs show an RxRL sequence overlapping another conserved motif LxFLAK [24]. Several sequences showing high similarity with Phytophthora CRN were detected in A. euteiches. The largest groups of CRNs showed strong similarity to P. infestans CRN5 (14 unigenes) or CRN13 (9 unigenes). Interestingly, the conserved LxLFLAK sequence was not present in A. euteiches genes, but a closely related motif, F/LxLYLALK, was detected (Figure 6). This is the first time that CRN genes are found in an organism distinct from Peronosporales suggesting that this class of effectors plays an important role in oomycete pathogenicity.

Bottom Line: 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.

View Article: PubMed Central - PubMed

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

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.

Show MeSH
Related in: MedlinePlus