Effects of two transglutaminases on innate immune responses in the oriental armyworm,Mythimna separata  

作　　者：Ying Zhu Seiichi Furukawa 

机构地区：[1]Degree Programs in Life and Earth Sciences,University of Tsukuba,Tsukuba,Japan [2]Faculty of Life and Environmental Sciences,University of Tsukuba,Tsukuba,Ibaraki,Japan

出　　处：《Insect Science》2025年第2期409-424,共16页昆虫科学(英文版)

基　　金：supported by the Japan Society for the Promotion of Science,KAKENHI[Grant Number JP17K08157].

摘　　要：Transglutaminase(TGase)is a key enzyme that mediates hemolymph coagulation and is thought to contribute to the elimination of pathogenic microorganisms in invertebrates.The objective of this study was to elucidate the involvement of TGase in insect immune responses via functional analysis of this enzyme in the oriental armyworm,Mythimna separata,using recombinant proteins and RNA interference technique.We identified two TGase genes,mystgase1 and mystgase2,in Mythimna separata and found that both genes are expressed in all surveyed tissues in M.separata larvae.Significant changes were induced in hemocytes following Escherichia coli injection.Injection of Gram-positive bacteria(Micrococcus luteus)and Gram-negative bacteria(Escherichia coli and Serratia marcescens)into larvae triggered a time-specific induction of both mystgase1 and mystgase2 in hemocytes.Recombinant MysTGase1 and MysTGase2 proteins bound to both E.coli and M.luteus,localizing within bacterial clusters and resulting in agglutination in a Ca2+-dependent manner.The hemocytes of larvae injected with recombinant MysTGase1 or MysTGase2 exhibited enhanced phagocytic ability against E.coli,improved in vivo bacterial clearance,and increased resistance to S.marcescens,decreasing larval mortality rate.Conversely,RNA interference targeting mystgase1 or mystgase2 significantly reduced hemocyte phagocytic capability,decreased bacterial clearance,and increased susceptibility to S.marcescens infection,thereby increasing larval mortality rate.The findings of this study are anticipated to expand our understanding of the function of TGases within insect immune responses and may contribute to developing new pest control strategies.

关 键 词：AGGLUTINATION gene expression hemolymph coagulation mortality PHAGOCYTOSIS RNA interference 

分 类 号：S433[农业科学—农业昆虫与害虫防治]