Baculovirus-mediated expression of a scorpion depressant toxin improves the insecticidal efficacy achieved with excitatory toxins

• Published in: FEBS letters 1998-01, Vol.422 (2), p.132-136
• Main Authors: Gershburg, Eduard, Stockholm, Daniel, Froy, Oren, Rashi, Sharon, Gurevitz, Michael, Chejanovsky, Nor
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Baculoviridae; Baculovirus; Cell Line; Depressant anti-insect toxin; Excitatory anti-insect toxin; Insect cell; Insecta; Insecticides; Kinetics; Lepidopteran larva; Molecular Sequence Data; Neurotoxins - toxicity; Paralysis; Recombinant Proteins - biosynthesis; Recombinant Proteins - chemistry; Recombinant Proteins - toxicity; Scorpion Venoms - biosynthesis; Scorpion Venoms - chemistry; Scorpion Venoms - toxicity; Spodoptera; Transfection
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/S0014-5793(97)01614-1

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 ET 50 (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 ET 50 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.