A007 1 1

Hepatopancreas were homogenized with PBS (1:9) and centrifuged immediately at 4000 × g, 4°C for 10 min. The obtained supernatants were used to measure biochemical parameters with relevant kits. Specifically, total protein was measured with BCA Protein Assay Kit (A045-3, Jiancheng Bioengineering Institute, Nanjing, China). Total antioxidant capacity (T-AOC), catalase (CAT), superoxide dismutase (SOD), reduced glutathione (GSH), and malondialdehyde (MDA) in supernatants were analyzed with A015–1, A007-1-1, A001–1, A006-1-1, and A003-1 kits (Jiancheng Bioengineering Institute, Nanjing, China), respectively. In addition, total cholesterol (T-CHO), lysozyme (LZM), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) in plasma were detected using A111-1-1, A050-1-1, C010-1-1, and C009-1-1 kits (Jiancheng Bioengineering Institute, Nanjing, China), respectively. The phenoloxidase (PO) determination was as referenced by Lin et al. (2012) (link) with kits (G0146W, Suzhou Grace Biotechnology Co., Ltd., China).

Supernatant of the liver homogenization solution was used to measure the activities of glutathione peroxidase (GSH-Px) and catalase (CAT) using the commercial kits (A005-1-2 and A007-1-1, Nanjing Jiancheng Bioengineering Institute) according to the instructions of the manufacturer. The total SOD (TSOD) and MnSOD activities were measured following the nitrite method described by Zhu et al., and CuZnSOD activity was calculated by subtracting MnSOD activity from TSOD activity. MT content was determined using an ELISA kit for duck species (CG3309, Waltham).

The CAT activity was measured through a kit (A007-1-1) provided by Nanjing Jiancheng Bioengineering Institute, Nanjing, China. The measurement process was conducted according to the instructions.

Thirty adult thrips were transferred into 2 mL centrifuge tubes. Then 800 μL of 0.4% normal saline was added and homogenized in an ice bath with a tissue grinder. After centrifugation at 2,500 r/min for 10 min, the supernatant was prepared as a coarse enzyme solution. The prepared enzyme solution was stored in the refrigerator at 4°C and used within 24 h. Determination of the protein content of the enzyme solution was the same as coomassie brilliant blue G-250 staining described above.
The antioxidant enzymes (SOD, CAT, and POD) were examined using commercially available assay kits (A001-1-1, A007-1-1, A084-1, Nanjing Jiancheng Bioengineering Institute, Nanjing, China) following the manufacturer’s protocols, and according to the method of Shi et al. (2013) (link). The specific calculation formulas of enzyme activity were as follows:
Catalase was determined spectrophotometrically at 405 nm by measuring the decrease of H₂O₂ due to H₂O₂ decomposition. CAT activities were defined as the amount that decomposes 1 μmol of H₂O₂ per second per mg protein (U mg^–1 protein). POD activity was determined at 420 nm by catalyzing the oxidation of a substrate in the presence of H₂O₂. One unit of POD activity was defined as the amount that catalyzes 1 μg substrate per minute per mg protein (U mg^–1 protein) (Jia et al., 2011 (link); Chen et al., 2018 (link)).