THE ENDOPARASITOID Campoletis chlorideae INDUCES A HEMOLYTIC FACTOR IN THE HERBIVOROUS INSECT Helicoverpa armigera.
Although lysis of invading organisms is a major innate form of immunity used by invertebrates, it remains unclear whether herbivorous insects have hemolysin or not. To address this general question, we tested the hemolytic (HL) activity of the hemolymph and tissue extracts from various stages of the polyphagous insect Helicoverpa armigera (Hübner) against the erythrocytes from chicken, duck, and rabbit. An HL activity was identified in the hemolymph of H. armigera larvae. Further studies demonstrated that the HL activity is proteinaceous as it was precipitable by deproteinizing agents. Hemolysins were found in Helicoverpa egg, larva, pupa, and adult, but the activity was higher in feeding larvae than in molting or newly molted larvae. Hemolysins were distributed among a variety of larval tissues including salivary gland, fat body, epidermis, midgut, or testes, but the highest activity was found in salivary gland and fat body. Relative to nonparasitized larvae, parasitization of H. armigera larvae by the endoparasitoid Campoletis chlorideae Uchida induced a 3.4-fold increase in the HL activity in the plasma of parasitized host at day two postparasitization. The present study shows the presence of a parasitoid inducible HL factor in the parasitized insect. The HL activity increased significantly in H. armigera larvae at 12 and 24 h postinjection with Escherichia coli. We infer the HL factor(s) is inducible or due to de novo synthesis, which means that the HL factor(s) is associated with insect immune response by inhibiting or clearance of invading organisms.
College of Plant Protection, Henan Agricultural University, Zhengzhou, Henan, China.
Xiong-Ya
XY
Wang
College of Plant Protection, Henan Agricultural University, Zhengzhou, Henan, China.
Su-Fen
SF
Bai
College of Plant Protection, Henan Agricultural University, Zhengzhou, Henan, China.
Xin
X
Li
College of Plant Protection, Henan Agricultural University, Zhengzhou, Henan, China.
Xin-Ming
XM
Yin
Department of Entomology and BIO5 Institute, The University of Arizona, Tucson, AZ, USA.|State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
Xian-Chun
XC
Li
D000818:Animals; D002645:Chickens; D004372:Ducks; D004912:Erythrocytes / Q000276:immunology; D004926:Escherichia coli / Q000502:physiology; D005260:Female; D006458:Hemolymph / Q000276:immunology / Q000378:metabolism; D006460:Hemolysin Proteins / Q000096:biosynthesis / Q000276:immunology*; D007113:Immunity, Innate; D007814:Larva / Q000276:immunology / Q000382:microbiology / Q000469:parasitology; D009036:Moths / Q000276:immunology* / Q000382:microbiology / Q000469:parasitology; D011817:Rabbits; D014863:Wasps / Q000502:physiology*
D006460:Hemolysin Proteins
Helicoverpa armigera; Hemolytic activity; endoparasitoid; innate immune; spatiotemporal profile