title: Biochemical basis of synergism between pathogenic fungus Metarhizium anisopliae and insecticide chlorantraniliprole in Locusta migratoria (Meyen).
abstract: We challenged Locusta migratoria (Meyen) grasshoppers with simultaneous doses of both the insecticide chlorantraniliprole and the fungal pathogen, Metarhizium anisopliae. Our results showed synergistic and antagonistic effects on host mortality and enzyme activities. To elucidate the biochemical mechanisms that underlie detoxification and pathogen-immune responses in insects, we monitored the activities of 10 enzymes. After administration of insecticide and fungus, activities of glutathione-S-transferase (GST), general esterases (ESTs) and phenol oxidase (PO) decreased in the insect during the initial time period, whereas those of aryl acylamidase (AA) and chitinase (CHI) increased during the initial period and that of acetylcholinesterase (AChE) increased during a later time period. Activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) decreased at a later time period post treatment. Interestingly, treatment with chlorantraniliprole and M. anisopliae relieved the convulsions that normally accompany M. anisopliae infection. We speculate that locust mortality increased as a result of synergism via a mechanism related to Ca(2+) disruption in the host. Our study illuminates the biochemical mechanisms involved in insect immunity to xenobiotics and pathogens as well as the mechanisms by which these factors disrupt host homeostasis and induce death. We expect this knowledge to lead to more effective pest control.
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, P. R. China.|Scientific Observation and Experimental Station of Pests, in Xilingol Rangeland, Ministry of Agriculture, xilin Gol League, Inner Mongolia, P. R. China.
authors.forename: Miao
authors.initials: M
authors.lastname: Jia
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, P. R. China.|Scientific Observation and Experimental Station of Pests, in Xilingol Rangeland, Ministry of Agriculture, xilin Gol League, Inner Mongolia, P. R. China.
authors.forename: Guangchun
authors.initials: G
authors.lastname: Cao
authors.affiliation: College of Plant Protection, Shenyang Agricultural University, Shenyang, P. R. China.
authors.forename: Yibo
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, P. R. China.|Scientific Observation and Experimental Station of Pests, in Xilingol Rangeland, Ministry of Agriculture, xilin Gol League, Inner Mongolia, P. R. China.
authors.forename: Xiongbing
authors.initials: X
authors.lastname: Tu
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, P. R. China.|Scientific Observation and Experimental Station of Pests, in Xilingol Rangeland, Ministry of Agriculture, xilin Gol League, Inner Mongolia, P. R. China.
authors.forename: Guangjun
authors.initials: G
authors.lastname: Wang
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, P. R. China.|Scientific Observation and Experimental Station of Pests, in Xilingol Rangeland, Ministry of Agriculture, xilin Gol League, Inner Mongolia, P. R. China.
authors.forename: Xiangqun
authors.initials: X
authors.lastname: Nong
authors.affiliation: School of Biological Sciences, Illinois State University, Normal, Illinois, USA.
authors.forename: Douglas W
authors.initials: DW
authors.lastname: Whitman
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, P. R. China.|Scientific Observation and Experimental Station of Pests, in Xilingol Rangeland, Ministry of Agriculture, xilin Gol League, Inner Mongolia, P. R. China.
authors.forename: Zehua
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000581:Amidohydrolases / Q000235:genetics; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002688:Chitinases; D004357:Drug Synergism; D004950:Esterases / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D005982:Glutathione Transferase / Q000235:genetics; D019476:Insect Proteins / Q000235:genetics*; D007306:Insecticides / Q000494:pharmacology*; D048188:Locusta migratoria / Q000187:drug effects / Q000201:enzymology* / Q000382:microbiology; D052981:Metarhizium / Q000502:physiology*; D014442:Monophenol Monooxygenase / Q000235:genetics; D062367:ortho-Aminobenzoates / Q000494:pharmacology*
chemical_list: D019476:Insect Proteins; D007306:Insecticides; D062367:ortho-Aminobenzoates; C517733:chlorantranilipole; D014442:Monophenol Monooxygenase; D005982:Glutathione Transferase; D004950:Esterases; D002688:Chitinases; D000581:Amidohydrolases; C019732:aryl acylamidase; D002118:Calcium