Effects of inhibitors on the protease profiles and degradation of activated Cry toxins in larval midgut juices of Cnaphalocrocis medinalis (Lepidoptera:Pyralidae)  

作　　者：YANG Ya-jun XU Hong-xing WU Zhi-hong LU Zhong-xian 

机构地区：[1]State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products,Institute of Plant Protection and Microbiology,Zhejiang Academy of Agricultural Sciences,Hangzhou 310021,P.R.China

出　　处：《Journal of Integrative Agriculture》2021年第8期2195-2203,共9页农业科学学报（英文版）

基　　金：This study was supported by the Zhejiang Provincial Natural Science Foundation of China(LY20C140004);the National Science and Technology Major Project of China(2016ZX08001001);the National Natural Science Foundation of China(31501669);the earmarked fund for China Agriculture Research System(CARS-01-36).

摘　　要：Midgut juice plays an important role in food digestion and detoxification in insects.In order to understand the potential of midgut juice of Cnaphalocrocis medinalis(Guenée)to degrade Bt proteins,the enzymatic activity of midgut juice and its degradation of Bt proteins(Cry2A,Cry1C,Cry1Aa,and Cry1Ac)were evaluated in this study through protease inhibitor treatments.The activities of total protease in midgut juices were significantly inhibited by phenylmethylsulfonyl fluoride(PMSF),tosyl-L-lysine chloromethyl ketone(TLCK),pepstatin A and leupeptin.The enzymatic activity of chymotrypsin was significantly inhibited by PMSF,and enzymatic activity of trypsin was significantly inhibited by ethylenediaminetetraacetic acid(EDTA),PMSF,tosyl phenylalanine chloromethyl ketone(TPCK),TLCK and trans-epoxysuccinyl-L-leucylamido-(4-guanidino)butane(E-64).EDTA could significantly inhibit the degradation of Cry2A by C.medinalis.EDTA,PMSF,TPCK,and TLCK could inhibit the degradation of Cry1C and Cry1Aa.EDTA,PMSF,TPCK,TLCK,and E-64 could inhibit the degradation of Cry1Ac.Our results indicated that some protease inhibitors hindered various enzymatic activities in the larval midgut of C.medinalis,which may reduce the insect’s ability to degrade Bt toxins.These findings may aid the application of protease inhibitors in the management of this insect pest in the future.

关 键 词：Cnaphalocrocis medinalis midgut juice protease inhibitor enzyme activity DEGRADATION Bt protein 

分 类 号：TQ450.1[化学工程—农药化工]