Topical treatment of LdMNPV-infected gypsy moth caterpillars with 18 nucleotides long antisense fragment from LdMNPV IAP3 gene triggers higher levels of apoptosis in infected cells and mortality of the pest

Th e high effi ciency of baculovirus infection is partially explained by the ability of the virus to suppress host defense machinery connected with the apoptosis pathway. Members of the baculovirus gene family, inhibitors of apoptosis (vIAPs), have been shown to inhibit apoptosis in baculovirus-infected cells. Here we showed that treatment of the LdMNPV-infected 1st instar gypsy moth (Lymantria dispar) caterpillars with sense (oligoBIR) and antisense (oligoRING) DNA oligonucleotides from the LdMNPV IAP3 gene induced elevated mortality of the insects. Apoptotic DNA ladder assay showed that the leading role in this phenomenon is played by the antisense oligoRING fragment of the vIAP3 gene. Th ese results imply that the application of both antisense DNA oligonucleotides from vIAP genes and baculovirus preparations (one following the other) may be a potential method for plant protection against insect pests.