title: Expression of a barley cystatin gene in maize enhances resistance against phytophagous mites by altering their cysteine-proteases.
abstract: Phytocystatins are inhibitors of cysteine-proteases from plants putatively involved in plant defence based on their capability of inhibit heterologous enzymes. We have previously characterised the whole cystatin gene family members from barley (HvCPI-1 to HvCPI-13). The aim of this study was to assess the effects of barley cystatins on two phytophagous spider mites, Tetranychus urticae and Brevipalpus chilensis. The determination of proteolytic activity profile in both mite species showed the presence of the cysteine-proteases, putative targets of cystatins, among other enzymatic activities. All barley cystatins, except HvCPI-1 and HvCPI-7, inhibited in vitro mite cathepsin L- and/or cathepsin B-like activities, HvCPI-6 being the strongest inhibitor for both mite species. Transgenic maize plants expressing HvCPI-6 protein were generated and the functional integrity of the cystatin transgene was confirmed by in vitro inhibitory effect observed against T. urticae and B. chilensis protein extracts. Feeding experiments impaired on transgenic lines performed with T. urticae impaired mite development and reproductive performance. Besides, a significant reduction of cathepsin L-like and/or cathepsin B-like activities was observed when the spider mite fed on maize plants expressing HvCPI-6 cystatin. These findings reveal the potential of barley cystatins as acaricide proteins to protect plants against two important mite pests.
authors.affiliation: Dpto. Biología Medioambiental, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maéztu 9, 28040 Madrid, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Carrillo
authors.forename: Manuel
authors.initials: M
authors.lastname: Martinez
authors.forename: Koreen
authors.initials: K
authors.lastname: Ramessar
authors.forename: Inés
authors.initials: I
authors.lastname: Cambra
authors.forename: Pedro
authors.initials: P
authors.lastname: Castañera
authors.forename: Felix
authors.initials: F
authors.lastname: Ortego
authors.forename: Isabel
authors.initials: I
authors.lastname: Díaz
mesh_terms: D000818:Animals; D001483:Base Sequence; D003433:Crosses, Genetic; D015891:Cystatins / Q000235:genetics* / Q000494:pharmacology; D057056:Cysteine Proteases / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D005247:Feeding Behavior / Q000187:drug effects; D017343:Genes, Plant / Q000235:genetics; D001467:Hordeum / Q000187:drug effects / Q000235:genetics*; D007113:Immunity, Innate / Q000187:drug effects / Q000235:genetics*; D008925:Mites / Q000187:drug effects / Q000201:enzymology* / Q000502:physiology; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000235:genetics / Q000276:immunology* / Q000469:parasitology; D030821:Plants, Genetically Modified; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000494:pharmacology; D013379:Substrate Specificity / Q000187:drug effects; D014170:Transformation, Genetic / Q000187:drug effects; D003313:Zea mays / Q000187:drug effects / Q000235:genetics* / Q000469:parasitology
chemical_list: D015891:Cystatins; D011994:Recombinant Proteins; D057056:Cysteine Proteases