Enhancing the insecticidal potential of a baculovirus by overexpressing the mammalian β‐galactosyl binding protein galectin‐1

Abstract

Developing bio-pesticides is an important area of research in agriculture for which viruses are an essential tool. Infection by entomological pathogenic viruses kills agricultural pests, and viral progenies are disseminated to infect more pests, eventually achieving long-term pest control in the eld. Of the current virus-based pest control models, Autographa californica multiple nucleopolyhedrovirus (AcMNPV) is the most studied. AcMNPV belongs to the family Baculoviridae and can infect many lepidopterans. Although AcMNPV has been previously demonstrated as a potential pest-control tool, its long virus infection cycle has made eld application challenging. To overcome this hurdle, we generated a recombinant baculovirus that can express mammalian galectin-1, which is a-galactoside-binding protein that binds to the peritrophic matrix in the midgut of pest lepidopterans and induces perforation of the membrane. Galectin-1 has been shown to affect immune responses in mammals, including humans, but to our knowledge, the effect of galectin-1 on insect immune systems has not been previously reported.Hosts infected with this recombinant virus exhibited reduced appetite and died sooner in both laboratory and small-scale eld studies, suggesting that the overexpression of galectin-1 can more e ciently eliminate pest hosts. In addition to disrupting the integrity of the peritrophic matrix, the immune system of hosts infected with recombinant baculovirus carrying the galectin-1 gene was suppressed, making hosts more vulnerable to secondary infection. These results demonstrated that the potential of baculovirus for pest control can be improved by using a recombinant baculovirus that overexpresses mammalian galectin-1 in hosts. Key MessageBaculoviruses facilitate recombinant protein production and play important roles in pest management.Mammalian galectin-1 exhibited activity toward insect larvae via midgut peritrophic membranes.Mammalian galectin-1 immune gene expression and cell-mediated immunity in Spodoptera litura.Baculovirus insecticidal activity was synergistically enhanced by co-expression of galectin-1.

Insecticidal action of mammalian galectin‐1‐transfected Arabidopsis thaliana

“…Our recent studies have shown that the pest control potential of baculoviruses can be improved using a recombinant baculovirus that overexpresses mammalian GAL1 in hosts. 44 In conclusion, the current results suggest that GAL1 binds to the chitin constituent of P. xylostella PM, resulting in a change in its permeability, thereby allowing bacteria or toxins in ingested food to enter the epithelium and damage the intestinal lining. Finally, insects die because of the accumulation/proliferation of toxins and bacteria in the body cavity, gut paralysis that reduces food consumption, and resultant starvation.…”

“…The combination of GAL1 with AcMNPV or Bt ‐toxin may synergistically enhance the insecticidal activity of AcMNPV . Our recent studies have shown that the pest control potential of baculoviruses can be improved using a recombinant baculovirus that overexpresses mammalian GAL1 in hosts 44 …”