title: Differential in vitro and in vivo effect of barley cysteine and serine protease inhibitors on phytopathogenic microorganisms.
abstract: Protease inhibitors from plants have been involved in defence mechanisms against pests and pathogens. Phytocystatins and trypsin/α-amylase inhibitors are two of the best characterized protease inhibitor families in plants. In barley, thirteen cystatins (HvCPI-1 to 13) and the BTI-CMe trypsin inhibitor have been previously studied. Their capacity to inhibit pest digestive proteases, and the negative in vivo effect caused by plants expressing these inhibitors on pests support the defence function of these proteins. Barley cystatins are also able to inhibit in vitro fungal growth. However, the antifungal effect of these inhibitors in vivo had not been previously tested. Moreover, their in vitro and in vivo effect on plant pathogenous bacteria is still unknown. In order to obtain new insights on this feature, in vitro assays were made against different bacterial and fungal pathogens of plants using the trypsin inhibitor BTI-CMe and the thirteen barley cystatins. Most barley cystatins and the BTI-CMe inhibitor were able to inhibit mycelial growth but no bacterial growth. Transgenic Arabidopsis plants independently expressing the BTI-CMe inhibitor and the cystatin HvCPI-6 were tested against the same bacterial and fungal pathogens. Neither the HvCPI-6 expressing transgenic plants nor the BTI-CMe ones were more resistant to plant pathogen fungi and bacteria than control Arabidopsis plants. The differences observed between the in vitro and in planta assays against phytopathogenic fungi are discussed.
authors.affiliation: Centro de Biotecnología y Genómica de Plantas, Campus Montegancedo, Universidad Politécnica de Madrid, Autovía M40 (Km 38), 28223-Pozuelo de Alarcón, Madrid, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Carrillo
authors.forename: Ignacio
authors.initials: I
authors.lastname: Herrero
authors.forename: Inés
authors.initials: I
authors.lastname: Cambra
authors.forename: Rosa
authors.initials: R
authors.lastname: Sánchez-Monge
authors.forename: Isabel
authors.initials: I
authors.lastname: Diaz
authors.forename: Manuel
authors.initials: M
authors.lastname: Martinez
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000935:Antifungal Agents / Q000494:pharmacology; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000382:microbiology*; D015891:Cystatins / Q000235:genetics / Q000494:pharmacology*; D056625:Endosperm / Q000737:chemistry; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005670:Fusarium / Q000187:drug effects; D005822:Genetic Vectors / Q000235:genetics / Q000378:metabolism; D001467:Hordeum / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D025282:Mycelium / Q000187:drug effects / Q000254:growth & development; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics / Q000494:pharmacology; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D044224:Pseudomonas syringae / Q000187:drug effects; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014170:Transformation, Genetic; D014361:Trypsin Inhibitors / Q000235:genetics / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D015891:Cystatins; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D014361:Trypsin Inhibitors