文献类型：期刊文献

英文题名：The competence of hemocyte immunity in the armyworm Mythimna separata larvae to sublethal hexaflumuron exposure

作者：Huang, Qingchun[1];Zhang, Lei[1];Yang, Chao[1];Yun, Xinmin[1];He, Yuan[1]

机构：[1]E China Univ Sci & Technol, Shanghai Key Lab Chem Biol, Sch Pharm, Shanghai 200237, Peoples R China

年份：2016

卷号：130

起止页码：31

外文期刊名：PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000375895800005)】；

基金：This work was financially supported by the Shanghai Foundation of Science and Technology (No. 15431906800) and the National Key Technology R&D Program (No. 2011BAE06B04).

语种：英文

外文关键词：Hemocyte immunity; Mythimna separata; Hexaflumuron; Sublethal exposure

摘要：Hemocytes circulating in the hemolymph are essential for the insect immunity to protect insects against infections. The effects of sublethal hexaflumuron exposure on the competence of hemocyte immunity of fifth-instar larvae of Mythimna separata were investigated. In this insect, the sublethal exposure could cause plasmatocyte filopodia to contract and shorten, and granulocytes to compact with a loss of cytoplasmic projections in vitro, and induce granulocytes to swell and expand in vivo. The mean number of total hemocytes was significantly declined in feed-thru larvae by 5.0 mu g mL(-1) hexaflumuron. Changes in proportional counts of hemocytes showed that sublethal hexaflumuron exposure caused a decrease of granulocytes and an increase of plasmatocytes in a concentration-dependant manner, but these changes were time-dependently reduced. Few effects of the sublethal exposure were revealed on the proportional counts of spherulocytes, oenocytoids, and prohemocytes. The exposure at 24 h showed strong inhibition on phenoloxidase activity in plasma and hemocytes, but this inhibition was time-dependently weakened. The NADPH-diaphorase staining assays showed that a positive immune response of nitric oxide synthase (NOS) in hemocytes was incited by the sublethal exposure, and the longer time exposure to the higher concentrations of hexaflumuron caused a heavier loss of NOS activity. Phagocytosis rates revealed the inhibitory effect of sublethal hexaflumuron exposure on the phagocytic ability of granulocytes and plasmatocytes that was significantly greater than the effect of chlorpyrifos at the same concentrations. These results show that sublethal hexaflumuron exposure reduces M. separata larval survival by depressing the competence of hemocyte-mediated immune responses. (C) 2015 Elsevier Inc. All rights reserved.