Abstract
Background Baculoviruses can be inactivated by ultraviolet (UV) light, which limits their application as an efficient biopesticide. In an attempt to enhance virus resistance to UV inactivation, a photolyase gene, isolated from Spodoptera litura granulovirus (SpliGV), was expressed in a photolyase deficient Spodoptera littoralis nucleopolyhedrovirus (SpliNPV) and the infectivity of recombinant virus expressing phr gene was determined after exposure to UV irradiation. Results Expression of the photolyase resulted in a fivefold resistance of virus occlusion bodies of the recombinant virus (vSpli-phr) compared to the wild type SpliNPV upon exposure to UV irradiation as measured by LC50 value when fed on S. littoralis neonate. Furthermore, the recombinant virus expressing phr showed a significant decrease in the time required for lethality than the control virus with about 22 h, as measured by ST50 value. Hence, expression of photolyase via vSpli-phr relatively may rescue the viral DNA damage caused by UV irradiation. Conclusions This study provided the evidence that the generated recombinant virus encoding a functioning photolyase, which may have implications for the development of a new generation of baculoviruses with enhanced insect pest management capabilities.