title: Genome analysis of the sugar beet pathogen Rhizoctonia solani AG2-2IIIB revealed high numbers in secreted proteins and cell wall degrading enzymes.
abstract: BACKGROUND
  Sugar beet (Beta vulgaris) is a crop cultivated for its high content in sugar, but it is vulnerable to many soil-borne pathogens. One of them is the basidiomycete Rhizoctonia solani. This fungal species has a compatibility system regulating hyphal fusions (anastomosis). Consequently, R. solani species are categorized in anastomosis groups (AGs). AG2-2IIIB isolates are most aggressive on sugar beet. In the present study, we report on the draft genome of R. solani AG2-2IIIB using the Illumina technology. Genome analysis, interpretation and comparative genomics of five sequenced R. solani isolates were carried out.
  
  
  RESULTS
  The draft genome of R. solani AG2-2IIIB has an estimated size of 56.02 Mb. In addition, two normalized EST libraries were sequenced. In total 20,790 of 21,980 AG2-2IIIB isotigs (transcript isoforms) were mapped on the genome with more than 95 % sequence identity. The genome of R. solani AG2-2IIIB was predicted to harbor 11,897 genes and 4908 were found to be isolate-specific. R. solani AG2-2IIIB was predicted to contain 1142 putatively secreted proteins and 473 of them were found to be unique for this isolate. The R. solani AG2-2IIIB genome encodes a high number of carbohydrate active enzymes. The highest numbers were observed for the polysaccharide lyases family 1 (PL-1), glycoside hydrolase family 43 (GH-43) and carbohydrate estarase family 12 (CE-12). Transcription analysis of selected genes representing different enzyme clades revealed a mixed pattern of up- and down-regulation six days after infection on sugar beets featuring variable levels of resistance compared to mycelia of the fungus grown in vitro.
  
  
  CONCLUSIONS
  The established R. solani AG2-2IIIB genome and EST sequences provide important information on the gene content, gene structure and transcriptional activity for this sugar beet pathogen. The enriched genomic platform provides an important platform to enhance our understanding of R. solani biology.
authors.affiliation: Institute for Genome Research and Systems Biology, CeBiTec, Bielefeld University, D-33501, Bielefeld, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Wibberg
authors.affiliation: Syngenta Seeds AB, Säbyholmsvägen 24, 26191, Landskrona, Sweden.|Swedish University of Agricultural Sciences, Department of Plant Biology, Uppsala BioCenter, Linnean Center for Plant Biology, P.O. Box 7080, S-75007, Uppsala, Sweden.
authors.forename: Louise
authors.initials: L
authors.lastname: Andersson
authors.affiliation: Swedish University of Agricultural Sciences, Department of Plant Biology, Uppsala BioCenter, Linnean Center for Plant Biology, P.O. Box 7080, S-75007, Uppsala, Sweden.
authors.forename: Georgios
authors.initials: G
authors.lastname: Tzelepis
authors.affiliation: Bioinformatics and Systems Biology, Gießen University, D-35392, Gießen, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Rupp
authors.affiliation: Bioinformatics and Systems Biology, Gießen University, D-35392, Gießen, Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Blom
authors.affiliation: Bioinformatics and Systems Biology, Gießen University, D-35392, Gießen, Germany.
authors.forename: Lukas
authors.initials: L
authors.lastname: Jelonek
authors.affiliation: Institute for Genome Research and Systems Biology, CeBiTec, Bielefeld University, D-33501, Bielefeld, Germany.
authors.forename: Alfred
authors.initials: A
authors.lastname: Pühler
authors.affiliation: Swedish University of Agricultural Sciences, Department of Plant Biology, Uppsala BioCenter, Linnean Center for Plant Biology, P.O. Box 7080, S-75007, Uppsala, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Fogelqvist
authors.affiliation: Institute for sugar beet research, IfZ, Göttingen, Germany.
authors.forename: Mark
authors.initials: M
authors.lastname: Varrelmann
authors.affiliation: Institute for Genome Research and Systems Biology, CeBiTec, Bielefeld University, D-33501, Bielefeld, Germany. aschluet@cebitec.uni-bielefeld.de.
authors.forename: Andreas
authors.initials: A
authors.lastname: Schlüter
authors.affiliation: Swedish University of Agricultural Sciences, Department of Plant Biology, Uppsala BioCenter, Linnean Center for Plant Biology, P.O. Box 7080, S-75007, Uppsala, Sweden. Christina.Dixelius@slu.se.
authors.forename: Christina
authors.initials: C
authors.lastname: Dixelius
mesh_terms: D027461:Beta vulgaris / Q000382:microbiology*; D002874:Chromosome Mapping; D055028:Comparative Genomic Hybridization; D020224:Expressed Sequence Tags; D016681:Genome, Fungal; D010935:Plant Diseases / Q000382:microbiology; D012232:Rhizoctonia / Q000201:enzymology / Q000235:genetics*; D017422:Sequence Analysis, DNA
keywords: Beta vulgaris; Carbohydrate active enzymes; Carbohydrate esterases; Glycoside hydrolases; Polysaccharide lyases; Rhizoctonia solani; Sugar beet pathogens