title: [Effects of soybean trypsinase inhibitor and defense signaling compounds on detoxification enzymes in Spodoptera litura (F.) larvae].
abstract: In a long history of interactions between insects and plants, plants have developed various anti-insect compounds and defense signaling transduction pathways to defend against herbivorous insects, while insects have responded with sophisticated detoxification enzyme systems to protect against the toxicity of anti-insect compounds. In this study, the 2nd or 3rd instar of Spodoptera litura larvae were successively fed with the diets containing 0.5% soybean trypsinase inhibitor (SBTI) for six generations to evaluate the effects of SBTI and defense signaling compounds on the activities of detoxification enzymes carboxylesterase (CarE) and glutathione-S-transferase (GST) in the midgut and fatbody of the larvae. After fed with the diets, the CarE and GST activities in the 5th instar larvae increased significantly. The CarE activity in the midgut and fatbody of the second generation larvae was the highest, being 2.06 and 2.40 times, and 1.96 and 2.70 times of that of the control, and the GST activity in the midgut and fatbody of the fourth and second generations was the highest, being 7.03 and 11.58 times, and 5.71 and 3.60 times of that of the control, respectively. These induced enzyme activities decreased gradually when the larvae continuously grew with the SBTI-containing diets. In addition, when the S. litura larvae were pre-exposed to methyl jasmonate (MeJA) or methyl salicylate (MeSA) for 48 h or fed with the diets containing 0.5% SBTI, the activities of CarE and GST in the midgut and fatbody increased significantly, and, when the 2nd instar larvae were pre-exposed to MeJA and MeSA for 48 h, the effects of SBTI on the GST activity in larval midgut and fatbody were reduced.
authors.affiliation: State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, Guangzhou 510642, China. yueyue970203@126.com
authors.forename: Guo-Zhao
authors.initials: GZ
authors.lastname: Wu
authors.forename: Lin
authors.initials: L
authors.lastname: Hu
authors.forename: Mao
authors.initials: M
authors.lastname: Ye
authors.forename: Rui-Long
authors.initials: RL
authors.lastname: Wang
authors.forename: Ke-Yan
authors.initials: KY
authors.lastname: Zhu
authors.forename: Ren-Sen
authors.initials: RS
authors.lastname: Zeng
authors.forename: Wen
authors.initials: W
authors.lastname: Cai
mesh_terms: D000818:Animals; D043182:Carboxylesterase / Q000187:drug effects*; D005982:Glutathione Transferase / Q000187:drug effects*; D006790:Host-Parasite Interactions; D007814:Larva / Q000201:enzymology; D010935:Plant Diseases / Q000517:prevention & control; D057865:Plant Immunity; D011480:Protease Inhibitors / Q000494:pharmacology; D015398:Signal Transduction; D018411:Spodoptera / Q000201:enzymology*; D014360:Trypsin Inhibitor, Kunitz Soybean / Q000494:pharmacology*
chemical_list: D011480:Protease Inhibitors; D014360:Trypsin Inhibitor, Kunitz Soybean; D005982:Glutathione Transferase; D043182:Carboxylesterase