Analysis Of The Protein Related To The Sensibility To Chlorpyrifos Of Diamondback Moth, Plutella Xylostella

With the emergence and development of proteomics, it is becoming a hot spot to study the physiological mechanism of insect's resistance to pesticides at protein level. This MSc-oriented thesis deals mainly with the pharmaceutically-related protein of diamondback moth (DBM), Plutella xylostella, of different instars and different strains using two dimensional electrophoresis and MALDI-TOF MS. The results we obtained can be a foundation for establishing a better integrated DBM management system, conducting further research on pest resistance at protein level, and looking for a new target site in pesticides developing.1. Protein expression in different instars of DBM larvaWe found 15 different proteins from three different instars (2, 3, 4) of DBM larva, among which 7 proteins were up-regulated with development of larva, 7 proteins were not existing in the 2nd instar, but present in the 3rd and 4th instar of larva. Based on the Mascot and NCBInr database, 11 proteins have been well matched, including H+ transporting ATP synthase subunit d, pxSerpinâ…¡, glucose dehydrogenase, Glutamic-oxaloacetic transaminaseâ… , triacylglycerol lipase, phosphoglyceromutase, Apolipophorin-III, cytochrome oxidase submitâ… , adenylate kinaseâ… , isopentenyl-diphosphate delta isomerase, ribosomal protein L18. In addition, we have compared the 3rd and 4th instar larva of resistant strain, 5 proteins were found differentially expressed, and only one protein existed in the 3rd instar, 2 up-regulated and 2 down-regulated in the 4th instar. Based again on Mascot and NCBInr database, 2 proteins were well matched, including electron-transfor-flavoprotein alpha polypeptide, translation initation factor 5A.2. Protein expression in different strains of DBM larvaFour proteins were found differentially expressed in the 3rd instar of larva between susceptible and resistant strains, 2 down-regulated in the resistant strain, 2 were not found in the susceptible strain, but present in the resistant strain. Eight different proteins existed in the 4th instar of larva, only one protein existed in the resistant strain, 7 down-regulated in the resistant strain. Based on the Mascot and NCBInr database, 9 proteins were well matched, including prohibition protein product, actin-depolymerizing factor 4, glyceraldehyde-3-phosphate dehydrogenase, nucleoside diphosphate kinase, isocitrate dehydrogenase, phosphoglyceromutase, glucose dehydrogenase.Most of the above-mentioned proteins are important enzymes in the metabolism system or immune system, or in the process of transcription and translation. It can be predicted, therefore, that these proteins may be related to the resistance of P. xylostella.