title: A cerato-platanin-like protein HaCPL2 from Heterobasidion annosum sensu stricto induces cell death in Nicotiana tabacum and Pinus sylvestris.
abstract: The cerato-platanin family is a group of small secreted cysteine-rich proteins exclusive for filamentous fungi. They have been shown to be involved in the interactions between fungi and plants. Functional characterization of members from this family has been performed mainly in Ascomycota, except Moniliophthora perniciosa. Our previous phylogenetic analysis revealed that recent gene duplication of cerato-platanins has occurred in Basidiomycota but not in Ascomycota, suggesting higher functional diversification of this protein family in Basidiomycota than in Ascomycota. In this study, we identified three cerato-platanin homologues from the basidiomycete conifer pathogen Heterobasidion annosum sensu stricto. Expression of the homologues under various conditions as well as their roles in the H. annosum s.s.-Pinus sylvestris (Scots pine) pathosystem was investigated. Results showed that HaCPL2 (cerato-platanin-like protein 2) had the highest sequence similarity to cerato-platanin from Ceratocystis platani and hacpl2 was significantly induced during nutrient starvation and necrotrophic growth. The treatment with recombinant HaCPL2 induced cell death, phytoalexin production and defense gene expression in Nicotiana tabacum. Eliciting and cell death-inducing ability accompanied by retardation of apical root growth was also demonstrated in Scots pine seedlings. Our results suggest that HaCPL2 might contribute to the virulence of H. annosum s.s. by promoting plant cell death.
authors.affiliation: Department of Forest Sciences, P.O. Box 27, Latokartanonkaari 7, 00014, University of Helsinki, Helsinki, Finland. Electronic address: hongxin.chen@helsinki.fi.
authors.forename: Hongxin
authors.initials: H
authors.lastname: Chen
authors.affiliation: Department of Forest Sciences, P.O. Box 27, Latokartanonkaari 7, 00014, University of Helsinki, Helsinki, Finland.
authors.forename: Julia
authors.initials: J
authors.lastname: Quintana
authors.affiliation: Department of Forest Sciences, P.O. Box 27, Latokartanonkaari 7, 00014, University of Helsinki, Helsinki, Finland.
authors.forename: Andriy
authors.initials: A
authors.lastname: Kovalchuk
authors.affiliation: Department of Cell and Molecular Biology, Uppsala University, Box 596, Biomedical Center, SE-751 24 Uppsala, Sweden.
authors.forename: Wimal
authors.initials: W
authors.lastname: Ubhayasekera
authors.affiliation: Department of Forest Sciences, P.O. Box 27, Latokartanonkaari 7, 00014, University of Helsinki, Helsinki, Finland.
authors.forename: Fred O
authors.initials: FO
authors.lastname: Asiegbu
mesh_terms: D001203:Ascomycota / Q000235:genetics / Q000472:pathogenicity; D001487:Basidiomycota / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016923:Cell Death / Q000187:drug effects; D005656:Fungal Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D054884:Host-Pathogen Interactions; D010802:Phylogeny; D041605:Pinus sylvestris / Q000166:cytology / Q000187:drug effects* / Q000235:genetics / Q000382:microbiology; D010935:Plant Diseases / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D060888:Real-Time Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000494:pharmacology; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012717:Sesquiterpenes / Q000378:metabolism; D014026:Nicotiana / Q000166:cytology / Q000187:drug effects* / Q000235:genetics / Q000382:microbiology; D000094162:Phytoalexins
chemical_list: D005656:Fungal Proteins; D010940:Plant Proteins; D011994:Recombinant Proteins; D012717:Sesquiterpenes; D000094162:Phytoalexins
keywords: Fungal effector; Fungal elicitor; Phytotoxicity; Plant defense; Virulence