Effects Of Four Diets On Digestive Enzyme Activity And Proteomics Of Midgut Of Athetis Lepigones

Athetis lepigone(M?schler)is a species of newly occurred insect pest which damages the corn seedlings and has caused serious losses to summer corn in the Huang-Huai-Hai Region of China.It was reported that foodstuffs had a significant effect on the growth and development of the insects,the paper aimed to investigate the effects of foodstuffs on the activity of midgut digestive enzymes and midgut proteomics of Athetis lepigone to explore the physiological mechanism of the occurrence of the pest and also provide a theoretical basis for the integrated control of the insect pest.Main research results were as follows:1.The digestive enzyme activity in the midgut of Athetis lepigone larvae fed with four kinds of foods,the artificial diet,the wheat(Triticum aestivum L.),the newly-germinated wheat sprout and the corn(Zea mays),was determined in the lab.The results showed that the activity sizes of midgut protease in 4th and 5th instar larvae were in turn on newly-germinated wheat sprout >on artificial diet >on corn>on wheat;the activity sizes of LPS were in turn artificial diet>on newly-germinated wheat sprout>on corn>on wheat;the activity sizes of CL were in turn on newly-germinated wheat sprout>on artificial diet>on corn>on wheat;the activity sizes of AMS were in turn on newly-germinated wheat sprout>on wheat>on corn>on artificial diet.The enzymatic activities were lower in the 4th instar larvae than in the 5th instar larvae.2.The iTRAQ technique was used to identify and compare the proteogroups of artificial diet group,newly-germinated wheat sprout group,corn group and wheat group.The results were as follows:(1)There were 101 differentially expressed proteins in artificial diet group and newly-germinated wheat sprout group,of which 52 proteins were up-regulated and 49 proteins were down-regulated.The differential protein gene is mainly involved in 25 signal pathways such as Glycolysis/Gluconeogenesis.(2)There were 43 differentially expressed proteins in the artificial diet group and the corn group,of which 23 proteins were up-regulated and 20 proteins were down-regulated.The differential protein genes are mainly involved in Insect hormone biosynthesis and other four signal pathways.(3)There were 32 differentially expressed proteins in the artificial diet group and wheat group,among which 18 proteins were up-regulated and 14 proteins were down-regulated.The differential protein genes mainly participate in 15 signal pathways such as Glycolysis/Gluconeogenesis.(4)There were 93 differentially expressed proteins in the corn group and newly-germinated wheat sprout group,among which 38 proteins were up-regulated and 55 proteins were down-regulated.The differential protein genes are mainly involved in 19 signal pathways such as Glycolysis/Gluconeogenesis.(5)There were 86 differentially expressed proteins in the newly-germinated wheat sprout group and wheat group,of which 53 proteins were up-regulated and 33 proteins were down-regulated.The differential protein genes are mainly involved in 19 signal pathways such as Glycolysis/Gluconeogenesis.(6)Four differentially expressed proteins were screened in the corn and wheat groups,all up-regulated.The above differential protein genes are mainly involved in ABC transporters and other three signal pathways.(7)The results showed that there were 6 differentially expressed proteins,namely,mitochondrial aldehyde dehydrogenase,juvenile hormone epoxide hydrolase-like protein 5,ribosomal protein S27 A,ribosomal protein L23 A,proteasome subunit beta type and 1 unknown protein.The functions of the differentially expressed proteins were discussed also.