title: Baculovirus-mediated expression of a scorpion depressant toxin improves the insecticidal efficacy achieved with excitatory toxins.
abstract: The insecticidal efficacy towards Helicoverpa armigera lepidopteran larvae of recombinant Autographa californica M nucleopolyhedroviruses, expressing depressant and excitatory scorpion anti-insect selective toxins, was investigated. The ET50 (effective paralysis time 50%) values obtained with the recombinant viruses expressing the depressant toxin, LqhIT2, and the excitatory toxin, LqhIT1, were 59 h and 66 h, respectively, whereas the ET50 value of the wild-type virus was longer, 87 h post infection. The insecticidal effects obtained when using two distinct temporally regulated viral promoters revealed advantage for the very late p10 promoter over the p35 early promoter. The higher insecticidity of the virus expressing the depressant toxin compared to the excitatory toxin suggests that pharmacokinetic factors and/or promoter efficiency may play a role during infection of insect pest larvae by recombinant baculoviruses.
authors.affiliation: Entomology Department, Institute of Plant Protection, ARO, The Volcani Center, Bet Dagan, Israel.
authors.forename: E
authors.initials: E
authors.lastname: Gershburg
authors.forename: D
authors.initials: D
authors.lastname: Stockholm
authors.forename: O
authors.initials: O
authors.lastname: Froy
authors.forename: S
authors.initials: S
authors.lastname: Rashi
authors.forename: M
authors.initials: M
authors.lastname: Gurevitz
authors.forename: N
authors.initials: N
authors.lastname: Chejanovsky
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016367:Baculoviridae; D002460:Cell Line; D007313:Insecta; D007306:Insecticides; D007700:Kinetics; D008969:Molecular Sequence Data; D009498:Neurotoxins / Q000633:toxicity*; D010243:Paralysis; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000633:toxicity; D012604:Scorpion Venoms / Q000096:biosynthesis / Q000737:chemistry / Q000633:toxicity*; D018411:Spodoptera; D014162:Transfection
chemical_list: D007306:Insecticides; C110767:LqhIT1 insect toxin; C076349:LqhIT2 insect toxin; D009498:Neurotoxins; D011994:Recombinant Proteins; D012604:Scorpion Venoms