title: Combining hexanoic acid plant priming with Bacillus thuringiensis insecticidal activity against Colorado potato beetle.
abstract: Interaction between insect herbivores and host plants can be modulated by endogenous and exogenous compounds present in the source of food and might be successfully exploited in Colorado potato beetle (CPB) pest management. Feeding tests with CPB larvae reared on three solanaceous plants (potato, eggplant and tomato) resulted in variable larval growth rates and differential susceptibility to Bacillus thuringiensis Cry3Aa toxin as a function of the host plant. An inverse correlation with toxicity was observed in Cry3Aa proteolytic patterns generated by CPB midgut brush-border membrane vesicles (BBMV) from Solanaceae-fed larvae, being the toxin most extensively proteolyzed on potato, followed by eggplant and tomato. We found that CPB cysteine proteases intestains may interact with Cry3Aa toxin and, in CPB BBMV from larvae fed all three Solanaceae, the toxin was able to compete for the hydrolysis of a papain substrate. In response to treatment with the JA-dependent plant inducer Hexanoic acid (Hx), we showed that eggplant reduced OPDA basal levels and both, potato and eggplant induced JA-Ile. CPB larvae feeding on Hx-induced plants exhibited enhanced Cry3Aa toxicity, which correlated with altered papain activity. Results indicated host-mediated effects on B. thuringiensis efficacy against CPB that can be enhanced in combination with Hx plant induction.
authors.affiliation: Department of Genetics, University of Valencia, Dr. Moliner 50, Burjassot 46100, Valencia, Spain. maria.dolores.real@uv.es.
authors.forename: Inmaculada
authors.initials: I
authors.lastname: García-Robles
authors.forename: Camila
authors.initials: C
authors.lastname: Ochoa-Campuzano
authors.forename: Emma
authors.initials: E
authors.lastname: Fernández-Crespo
authors.forename: Gemma
authors.initials: G
authors.lastname: Camañes
authors.forename: Amparo C
authors.initials: AC
authors.lastname: Martínez-Ramírez
authors.forename: Carmen
authors.initials: C
authors.lastname: González-Bosch
authors.forename: Pilar
authors.initials: P
authors.lastname: García-Agustín
authors.forename: Carolina
authors.initials: C
authors.lastname: Rausell
authors.forename: María Dolores
authors.initials: MD
authors.lastname: Real
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001413:Bacillus thuringiensis / Q000737:chemistry*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000633:toxicity; D001835:Body Weight / Q000187:drug effects; D002208:Caproates / Q000494:pharmacology*; D001517:Coleoptera / Q000187:drug effects* / Q000254:growth & development; D003120:Colorado; D057056:Cysteine Proteases / Q000378:metabolism; D004032:Diet; D004064:Digestive System / Q000187:drug effects / Q000201:enzymology; D015180:Electrophoresis, Gel, Two-Dimensional; D004731:Endotoxins / Q000633:toxicity; D005247:Feeding Behavior / Q000187:drug effects; D006460:Hemolysin Proteins / Q000633:toxicity; D054884:Host-Pathogen Interactions / Q000187:drug effects; D019476:Insect Proteins / Q000737:chemistry / Q000378:metabolism; D007306:Insecticides / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects / Q000235:genetics; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010455:Peptides / Q000378:metabolism; D010937:Plant Growth Regulators / Q000494:pharmacology; D059748:Proteolysis / Q000187:drug effects; D016415:Sequence Alignment; D011198:Solanum tuberosum / Q000469:parasitology*
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D002208:Caproates; D004731:Endotoxins; D006460:Hemolysin Proteins; D019476:Insect Proteins; D007306:Insecticides; D010455:Peptides; D010937:Plant Growth Regulators; C030956:insecticidal crystal protein, Bacillus Thuringiensis; C037652:hexanoic acid; D057056:Cysteine Proteases