title: Expression of serine proteases in egg-parasitic nematophagous fungi during barley root colonization.
abstract: Nematophagous fungi Pochonia chlamydosporia and P. rubescens colonize endophytically barley roots. During nematode infection, serine proteases are secreted. We have investigated whether such proteases are also produced during root colonization. Polyclonal antibodies against serine protease P32 of P. rubescens cross-reacted with a related protease (VCP1) of P. chlamydosporia, but not with barley proteases. These antibodies also detected an unknown ca. 65-kDa protein, labeled hyphae and appressoria of P. chlamydosporia and strongly reduced proteolytic activity of extracts from fungus-colonized roots. Mass spectrometry (MS) of 32-kDa protein bands detected peptides homologous to VCP1 only in Pochonia-colonized roots. Peptides homologous to barley serine carboxypeptidases were found in 65kDa bands of all roots. RT-PCR detected expression of VCP1 and a new P. chlamydosporia serine carboxypeptidase (SCP1) genes only in fungus-colonized roots. SCP1 shared limited sequence homology with VCP1 and P32. Expression in roots of proteases from nematophagous fungi could be greatly relevant for nematode biocontrol.
authors.affiliation: Multidisciplinary Institute for Environmental Studies (MIES) Ramón Margalef, Department of Marine Sciences and Applied Biology, University of Alicante, Aptdo. 99, 03080 Alicante, Spain. lv.lopez@ua.es <lv.lopez@ua.es>
authors.forename: Luis V
authors.initials: LV
authors.lastname: Lopez-Llorca
authors.forename: Sonia
authors.initials: S
authors.lastname: Gómez-Vidal
authors.forename: Elena
authors.initials: E
authors.lastname: Monfort
authors.forename: Eduardo
authors.initials: E
authors.lastname: Larriba
authors.forename: Juan
authors.initials: J
authors.lastname: Casado-Vela
authors.forename: Félix
authors.initials: F
authors.lastname: Elortza
authors.forename: Hans-Börje
authors.initials: HB
authors.lastname: Jansson
authors.forename: Jesús
authors.initials: J
authors.lastname: Salinas
authors.forename: José
authors.initials: J
authors.lastname: Martín-Nieto
mesh_terms: D000908:Antibodies, Fungal / Q000276:immunology; D000911:Antibodies, Monoclonal / Q000276:immunology; D015153:Blotting, Western; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D005656:Fungal Proteins / Q000096:biosynthesis* / Q000737:chemistry; D020869:Gene Expression Profiling; D001467:Hordeum / Q000382:microbiology*; D006999:Hypocreales / Q000201:enzymology* / Q000254:growth & development*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D018517:Plant Roots / Q000382:microbiology*; D012331:RNA, Fungal / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D057057:Serine Proteases / Q000096:biosynthesis* / Q000737:chemistry
chemical_list: D000908:Antibodies, Fungal; D000911:Antibodies, Monoclonal; D004271:DNA, Fungal; D005656:Fungal Proteins; D012331:RNA, Fungal; D057057:Serine Proteases