title: Plant immunity triggered by engineered in vivo release of oligogalacturonides, damage-associated molecular patterns.
abstract: Oligogalacturonides (OGs) are fragments of pectin that activate plant innate immunity by functioning as damage-associated molecular patterns (DAMPs). We set out to test the hypothesis that OGs are generated in planta by partial inhibition of pathogen-encoded polygalacturonases (PGs). A gene encoding a fungal PG was fused with a gene encoding a plant polygalacturonase-inhibiting protein (PGIP) and expressed in transgenic Arabidopsis plants. We show that expression of the PGIP-PG chimera results in the in vivo production of OGs that can be detected by mass spectrometric analysis. Transgenic plants expressing the chimera under control of a pathogen-inducible promoter are more resistant to the phytopathogens Botrytis cinerea, Pectobacterium carotovorum, and Pseudomonas syringae. These data provide strong evidence for the hypothesis that OGs released in vivo act as a DAMP signal to trigger plant immunity and suggest that controlled release of these molecules upon infection may be a valuable tool to protect plants against infectious diseases. On the other hand, elevated levels of expression of the chimera cause the accumulation of salicylic acid, reduced growth, and eventually lead to plant death, consistent with the current notion that trade-off occurs between growth and defense.
authors: Department of Biology and Biotechnology "Charles Darwin," Sapienza University of Rome, 00185 Rome, Italy;
authors: Manuel
authors: M
authors: Benedetti
authors: Department of Biology and Biotechnology "Charles Darwin," Sapienza University of Rome, 00185 Rome, Italy;
authors: Daniela
authors: D
authors: Pontiggia
authors: Department of Biology and Biotechnology "Charles Darwin," Sapienza University of Rome, 00185 Rome, Italy;
authors: Sara
authors: S
authors: Raggi
authors: Department of Genetics, Harvard Medical School, Boston, MA 02114; and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114.
authors: Zhenyu
authors: Z
authors: Cheng
authors: Department of Biology and Biotechnology "Charles Darwin," Sapienza University of Rome, 00185 Rome, Italy;
authors: Flavio
authors: F
authors: Scaloni
authors: Department of Biology and Biotechnology "Charles Darwin," Sapienza University of Rome, 00185 Rome, Italy;
authors: Simone
authors: S
authors: Ferrari
authors: Department of Genetics, Harvard Medical School, Boston, MA 02114; and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114 ausubel@molbio.mgh.harvard.edu felice.cervone@uniroma1.it.
authors: Frederick M
authors: FM
authors: Ausubel
authors: Department of Biology and Biotechnology "Charles Darwin," Sapienza University of Rome, 00185 Rome, Italy; ausubel@molbio.mgh.harvard.edu felice.cervone@uniroma1.it.
authors: Felice
authors: F
authors: Cervone
authors: Department of Biology and Biotechnology "Charles Darwin," Sapienza University of Rome, 00185 Rome, Italy;
authors: Giulia
authors: G
authors: De Lorenzo
mesh_terms: D000818:Animals; D017360:Arabidopsis / Q000235:genetics / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D020171:Botrytis / Q000254:growth & development / Q000276:immunology; D005656:Fungal Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D006603:Hexuronic Acids / Q000276:immunology / Q000378:metabolism*; D008822:Mice, Transgenic; D016973:Pectobacterium carotovorum / Q000254:growth & development / Q000276:immunology; D010935:Plant Diseases / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D057865:Plant Immunity; D010940:Plant Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D011096:Polygalacturonase / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D044224:Pseudomonas syringae / Q000254:growth & development / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology
chemical_list: D029681:Arabidopsis Proteins; D005656:Fungal Proteins; D006603:Hexuronic Acids; C081479:PGIP protein, plant; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; C007819:galacturonic acid; D011096:Polygalacturonase
keywords: DAMPs; PGIP; oligogalacturonides; plant immunity; polygalacturonase