The impact of co-infection by a nucleopolyhedrovirus and the endoparasitoid Microplitis pallidipes Szepligeti on the protective enzymes in hemolymph of Spodoptera exigua

ABSTRACT

We determined the effects of parasitism by Microplitis pallidipes and/or nucleopolyhedrovirus (NPV) infection on protective enzymes in the hemolymph of Spodoptera exigua larvae. We found that concentrations of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) were constantly higher within the five observation days after treatment in parasitized/virus-infected than healthy (control) larvae. In parasitized + infected larvae, enzyme levels reduced from day 1 compared to parasitized larvae. Compared to enzyme levels in virus-infected larvae, in parasitized + infected larvae, CAT concentrations were generally lower, while SOD concentrations were significantly lower in the first two days and POD concentrations were lower in the first two days, but higher in following three days. We concluded that joint and separate parasitism and NPV infection promoted the activities of protective enzymes. Our findings also revealed that NPV infection inhibited the activities of protective enzymes induced by parasitism of M. pallidipes and that the parasitism inhibited the CAT activity induced by NPV infection.

KEYWORDS:

• Catalase
• Microplitis pallidipes
• nucleopolyhedrovirus
• peroxidase
• Spodoptera exigua
• superoxide dismutase

Acknowledgments

We thank Prof. Roy Van Driesche at University of Massachusetts for improving the English of this manuscript and providing constructive comments that greatly improved the quality of our paper.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was funded by the grants from the National Natural Science Foundation of China [grant number 31672083]; Shanghai Agriculture Commission of China [grant number 2014-7-3-2], [grant number 2016-1-18]; and Shanghai Yang Fan Program [grant number 16YF1409900].