NeuroBactrus, a novel, highly effective, and environmentally friendly recombinant baculovirus insecticide.
A novel recombinant baculovirus, NeuroBactrus, was constructed to develop an improved baculovirus insecticide with additional beneficial properties, such as a higher insecticidal activity and improved recovery, compared to wild-type baculovirus. For the construction of NeuroBactrus, the Bacillus thuringiensis crystal protein gene (here termed cry1-5) was introduced into the Autographa californica nucleopolyhedrovirus (AcMNPV) genome by fusion of the polyhedrin-cry1-5-polyhedrin genes under the control of the polyhedrin promoter. In the opposite direction, an insect-specific neurotoxin gene, AaIT, from Androctonus australis was introduced under the control of an early promoter from Cotesia plutellae bracovirus by fusion of a partial fragment of orf603. The polyhedrin-Cry1-5-polyhedrin fusion protein expressed by the NeuroBactrus was not only occluded into the polyhedra, but it was also activated by treatment with trypsin, resulting in an ∼65-kDa active toxin. In addition, quantitative PCR revealed that the neurotoxin was expressed from the early phase of infection. NeuroBactrus showed a high level of insecticidal activity against Plutella xylostella larvae and a significant reduction in the median lethal time against Spodoptera exigua larvae compared to those of wild-type AcMNPV. Rerecombinant mutants derived from NeuroBactrus in which AaIT and/or cry1-5 were deleted were generated by serial passages in vitro. Expression of the foreign proteins (B. thuringiensis toxin and AaIT) was continuously reduced during the serial passage of the NeuroBactrus. Moreover, polyhedra collected from S. exigua larvae infected with the serially passaged NeuroBactrus showed insecticidal activity similar to that of wild-type AcMNPV. These results suggested that NeuroBactrus could be recovered to wild-type AcMNPV through serial passaging.
Department of Agricultural Biotechnology, College of Agriculture and Life Science, Seoul National University, Seoul, Republic of Korea.
Hee Jin
HJ
Shim
Jae Young
JY
Choi
Yong
Y
Wang
Xue Ying
XY
Tao
Qin
Q
Liu
Jong Yul
JY
Roh
Jae Su
JS
Kim
Woo Jin
WJ
Kim
Soo Dong
SD
Woo
Byung Rae
BR
Jin
Yeon Ho
YH
Je
D000818:Animals; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics; D016367:Baculoviridae / Q000235:genetics / Q000472:pathogenicity*; D004731:Endotoxins / Q000235:genetics; D015870:Gene Expression; D006460:Hemolysin Proteins / Q000235:genetics; D007306:Insecticides / Q000494:pharmacology*; D007814:Larva / Q000502:physiology / Q000821:virology; D007915:Lepidoptera / Q000502:physiology / Q000821:virology*; D030781:Organisms, Genetically Modified; D010572:Pest Control, Biological / Q000379:methods; D011995:Recombination, Genetic; D012604:Scorpion Venoms / Q000235:genetics; D016019:Survival Analysis
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; D007306:Insecticides; D012604:Scorpion Venoms; C030956:insecticidal crystal protein, Bacillus Thuringiensis; C065634:AaIT neurotoxin, Androctonus australis