title: Physcomitrella patens Activates Defense Responses against the Pathogen Colletotrichum gloeosporioides.
abstract: The moss Physcomitrella patens is a suitable model plant to analyze the activation of defense mechanisms after pathogen assault. In this study, we show that Colletotrichum gloeosporioides isolated from symptomatic citrus fruit infects P. patens and cause disease symptoms evidenced by browning and maceration of tissues. After C. gloeosporioides infection, P. patens reinforces the cell wall by the incorporation of phenolic compounds and induces the expression of a Dirigent-protein-like encoding gene that could lead to the formation of lignin-like polymers. C. gloeosporioides-inoculated protonemal cells show cytoplasmic collapse, browning of chloroplasts and modifications of the cell wall. Chloroplasts relocate in cells of infected tissues toward the initially infected C. gloeosporioides cells. P. patens also induces the expression of the defense genes PAL and CHS after fungal colonization. P. patens reporter lines harboring the auxin-inducible promoter from soybean (GmGH3) fused to β-glucuronidase revealed an auxin response in protonemal tissues, cauloids and leaves of C. gloeosporioides-infected moss tissues, indicating the activation of auxin signaling. Thus, P. patens is an interesting plant to gain insight into defense mechanisms that have evolved in primitive land plants to cope with microbial pathogens.
authors.affiliation: Department of Molecular Biology, Clemente Estable Biological Research Institute, Avenida Italia 3318, CP 11600 Montevideo, Uruguay. greboledo@iibce.edu.uy.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Reboledo
authors.affiliation: Department of Molecular Biology, Clemente Estable Biological Research Institute, Avenida Italia 3318, CP 11600 Montevideo, Uruguay. rdelcampo@iibce.edu.uy.
authors.forename: Raquel
authors.initials: R
authors.lastname: Del Campo
authors.affiliation: Department of Molecular Biology, Clemente Estable Biological Research Institute, Avenida Italia 3318, CP 11600 Montevideo, Uruguay. aalvarez@cin.edu.uy.|Laboratory of Plant Physiology, Nuclear Research Center, Faculty of Sciences, Mataojo 2055, CP 11400 Montevideo, Uruguay. aalvarez@cin.edu.uy.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Alvarez
authors.affiliation: Laboratory of Plant Physiology, Nuclear Research Center, Faculty of Sciences, Mataojo 2055, CP 11400 Montevideo, Uruguay. montesano@cin.edu.uy.
authors.forename: Marcos
authors.initials: M
authors.lastname: Montesano
authors.affiliation: Department of Molecular Biology, Clemente Estable Biological Research Institute, Avenida Italia 3318, CP 11600 Montevideo, Uruguay. hmara40@hotmail.com.
authors.forename: Héctor
authors.initials: H
authors.lastname: Mara
authors.affiliation: Department of Molecular Biology, Clemente Estable Biological Research Institute, Avenida Italia 3318, CP 11600 Montevideo, Uruguay. iponce@iibce.edu.uy.
authors.forename: Inés
authors.initials: I
authors.lastname: Ponce de León
mesh_terms: D001203:Ascomycota / Q000472:pathogenicity*; D044002:Bryophyta / Q000276:immunology / Q000382:microbiology*; D002473:Cell Wall / Q000378:metabolism; D002736:Chloroplasts / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism; D059828:Plant Cells / Q000378:metabolism; D057865:Plant Immunity; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D007210:Indoleacetic Acids; D010940:Plant Proteins
keywords: Colletotrichum gloeosporioides; Physcomitrella patens; auxin signaling; cell wall; chloroplasts relocation; defense responses; gene expression