We analyzed the composition and studied the bioactivity of secretion from the poplar sawfly, Stauronematus compressicornis （Fabricius）. A leaf-sandwich method was applied to test the bioactivity of the secretion. Co...We analyzed the composition and studied the bioactivity of secretion from the poplar sawfly, Stauronematus compressicornis （Fabricius）. A leaf-sandwich method was applied to test the bioactivity of the secretion. Coomassie brilliant blue, gas chromatography （GC） and other methods were used to analyze and carry out protein assays, amino acid analyses, fatty acid and cholesterol detection of the secretion. Results show that the secretion had a significant antifeeding effect on 4th instar larvae of the armyworm （Pseudaletia separata Walker）. Dissolved in 0.27 mol.L^-1 HCl, 0.1 mol.L^-1 NaOH and 0.05 mol.L^-1 Na2HPO4 separately, the secretions had antifeeding rates ranging from 22.7% to 49.6%. Meanwhile, the weights of the secretion-treated insects were significantly lower than those of the control. Biochemical detection showed that the proteins contained in the secretion were composed of 16 amino acids. The secretion also contained small amounts of cholesterol and fatty acids, which included lauric acid, myristic acid, myristoleic acid, seventeen carbonic acids and oleic acid.展开更多
The total protein increased in the gills and decreased in the muscle of the freshwater field crab Oziotelphusa senex senex at days 1 and 2 on exposure to lethal concentrations and at days 1 and 10 to sublethal concent...The total protein increased in the gills and decreased in the muscle of the freshwater field crab Oziotelphusa senex senex at days 1 and 2 on exposure to lethal concentrations and at days 1 and 10 to sublethal concentrations of furadan, endosulfan, chlorpyrifos, and a mixture of these three in a 100:10: 1 ratio. The increase in the gill protein was greater on exposure to the sublethal concentrations than to the lethal concentrations while the decrease in the muscle protein was greater on exposure to the lethal concentrations than to the sublethal concentrations. In the hepatopancreas, the protein content decreased on exposure to the lethal concentrations, but, in contrast, increased on exposure to the sublethal concentrations. These results clearly indicate that changes in the protein content are not only organ-dependent but also concentration-dependent, i.e., lethal versus sublethal. Irrespective of the changes in the total protein, the levels of free amino acids and the activities of protease, alanine and aspartate aminotransferases, and glutamate dehydrogenase increased in all the three organs of the crabs exposed to the lethal and sublethal concentrations, (more in lethal than in sublethal) and increased at a greater rate over time of exposure. Ammonia toxicity, measured by an increase in the hemolymph ammonia and a decrease in the urea, was also observed at the lethal concentrations of all the three pesticides. The ammonia and urea levels increased in the crabs exposed to the sublethal concentrations. Although the effect of each pesticide on the protein metabolism was similar, the degree of toxicity was the lowest on exposure to furadan, intermediate on exposure to endosulfan and chlorpyrifos, and cumulative on exposure to a mixture of the three pesticides展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 30872032).
文摘We analyzed the composition and studied the bioactivity of secretion from the poplar sawfly, Stauronematus compressicornis （Fabricius）. A leaf-sandwich method was applied to test the bioactivity of the secretion. Coomassie brilliant blue, gas chromatography （GC） and other methods were used to analyze and carry out protein assays, amino acid analyses, fatty acid and cholesterol detection of the secretion. Results show that the secretion had a significant antifeeding effect on 4th instar larvae of the armyworm （Pseudaletia separata Walker）. Dissolved in 0.27 mol.L^-1 HCl, 0.1 mol.L^-1 NaOH and 0.05 mol.L^-1 Na2HPO4 separately, the secretions had antifeeding rates ranging from 22.7% to 49.6%. Meanwhile, the weights of the secretion-treated insects were significantly lower than those of the control. Biochemical detection showed that the proteins contained in the secretion were composed of 16 amino acids. The secretion also contained small amounts of cholesterol and fatty acids, which included lauric acid, myristic acid, myristoleic acid, seventeen carbonic acids and oleic acid.
文摘The total protein increased in the gills and decreased in the muscle of the freshwater field crab Oziotelphusa senex senex at days 1 and 2 on exposure to lethal concentrations and at days 1 and 10 to sublethal concentrations of furadan, endosulfan, chlorpyrifos, and a mixture of these three in a 100:10: 1 ratio. The increase in the gill protein was greater on exposure to the sublethal concentrations than to the lethal concentrations while the decrease in the muscle protein was greater on exposure to the lethal concentrations than to the sublethal concentrations. In the hepatopancreas, the protein content decreased on exposure to the lethal concentrations, but, in contrast, increased on exposure to the sublethal concentrations. These results clearly indicate that changes in the protein content are not only organ-dependent but also concentration-dependent, i.e., lethal versus sublethal. Irrespective of the changes in the total protein, the levels of free amino acids and the activities of protease, alanine and aspartate aminotransferases, and glutamate dehydrogenase increased in all the three organs of the crabs exposed to the lethal and sublethal concentrations, (more in lethal than in sublethal) and increased at a greater rate over time of exposure. Ammonia toxicity, measured by an increase in the hemolymph ammonia and a decrease in the urea, was also observed at the lethal concentrations of all the three pesticides. The ammonia and urea levels increased in the crabs exposed to the sublethal concentrations. Although the effect of each pesticide on the protein metabolism was similar, the degree of toxicity was the lowest on exposure to furadan, intermediate on exposure to endosulfan and chlorpyrifos, and cumulative on exposure to a mixture of the three pesticides
