Insecticidal activity of two proteases against Spodoptera frugiperda larvae infected with recombinant baculoviruses.
BACKGROUND
Baculovirus comprise the largest group of insect viruses most studied worldwide, mainly because they efficiently kill agricultural insect pests. In this study, two recombinant baculoviruses containing the ScathL gene from Sarcophaga peregrina (vSynScathL), and the Keratinase gene from the fungus Aspergillus fumigatus (vSynKerat), were constructed, and their insecticidal properties analysed against Spodoptera frugiperda larvae.


RESULTS
Bioassays of third-instar and neonate S. frugiperda larvae with vSynScathL and vSynKerat showed a decrease in the time needed to kill the infected insects when compared to the wild type virus. We have also shown that both recombinants were able to increase phenoloxidase activity in the hemolymph of S. frugiperda larvae. The expression of proteases in infected larvae resulted in destruction of internal tissues late in infection, which could be the reason for the increased viral speed of kill.


CONCLUSIONS
Baculoviruses and their recombinant forms constitute viable alternatives to chemical insecticides. Recombinant baculoviruses containing protease genes can be added to the list of engineered baculoviruses with great potential to be used in integrated pest management programs.
Gramkow
Aline Welzel
AW
Cell Biology Department, University of Brasília, Brasília, DF, CEP 70910-970, Brazil.
Perecmanis
Simone
S
Sousa
Raul Lima Barbosa
RL
Noronha
Eliane Ferreira
EF
Felix
Carlos Roberto
CR
Nagata
Tatsuya
T
Ribeiro
Bergmann Morais
BM
D000818:Animals; D001232:Aspergillus fumigatus / Q000201:enzymology; D056668:Cathepsin L / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D002460:Cell Line; D004175:Diptera / Q000201:enzymology; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D005818:Genetic Engineering; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D007306:Insecticides / Q000378:metabolism / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects / Q000821:virology; D017924:Nucleopolyhedroviruses / Q000235:genetics* / Q000502:physiology; D010447:Peptide Hydrolases / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D010572:Pest Control, Biological / Q000379:methods*; D018411:Spodoptera / Q000187:drug effects / Q000254:growth & development / Q000821:virology*
D005656:Fungal Proteins; D019476:Insect Proteins; D007306:Insecticides; D010447:Peptide Hydrolases; C035855:keratinase; D056668:Cathepsin L