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Sublethal dose of phoxim and Bombyx mori nucleopolyhedrovirus interact to elevate silkworm mortality
Author(s) -
Gu ZhiYa,
Li FanChi,
Hu JingSheng,
Ding Chao,
Wang Chaoqian,
Tian JiangHai,
Xue Bin,
Xu KaiZun,
Shen WeiDe,
Li Bing
Publication year - 2017
Publication title -
pest management science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.296
H-Index - 125
eISSN - 1526-4998
pISSN - 1526-498X
DOI - 10.1002/ps.4326
Subject(s) - phoxim , bombyx mori , immune system , oxidative stress , pesticide , biology , toxicity , toxicology , pathogen , median lethal dose , microbiology and biotechnology , immunology , gene , medicine , biochemistry , ecology
Abstract BACKGROUND Silkworm ( Bombyx mori ) is an economically important insect. It is relatively less resistant to certain chemicals and environment exposures such as pesticides and pathogens. After pesticide exposures, the silkworms are more susceptible to microbial infections. The mechanism underlying the susceptibility might be related to immune response and oxidative stress. RESULTS A sublethal dose of phoxim combined with Bombyx mori nucleopolyhedrovirus (BmNPV) elevated the silkworm mortality at 96 h. We found a higher content of H 2 O 2 and increased levels of genes related to oxidative stress and immune response after treatment with a sublethal dose of phoxim for 24 h or 48 h. However, such response decreased with longer pesticide treatment. Mortality increased by 44% when B. mori was exposed to combined treatment with BmNPV and phoxim rather than BmNPV alone. The level of examined immune‐related and oxidative‐stress‐related genes significantly decreased in the combined treatment group compared with the BmNPV group. Our results indicated that, with long‐term exposure to pesticides such as OPs, even at sublethal dose, the oxidative stress response and immune responses in silkworm were inhibited, which may lead to further immune impairment and accumulation of oxidative stress, resulting in susceptibility to the virus and harm to the silkworm. CONCLUSION Our study provided insights for understanding the susceptibility to pathogen after pesticide exposures, which may promote the development of better pesticide controls to avoid significant economic losses. © 2016 Society of Chemical Industry