title: SRP gene is required for Helicoverpa armigera prophenoloxidase activation and nodulation response.
abstract: SRP gene was first identified from the fall webworm, Hyphantria cunea as one of genes up-regulated after bacteria injection. A rent study in Spodoptera litura showed that stress-induced elevation of SRP expression highly correlates with reduced feeding activities and growth retardation of larvae. In this study, we identified a SRP gene from the cotton bollworm, Helicoverpa armigera, namely Ha-SRP, and studied its precise roles in insect immunity. Expressions of Ha-SRP were upregulated in H. armigera larval hemocytes after injection of Escherichia coli. When the expression of Ha-SRP in H. armigera larval hemocytes was inhibited by dsHa-SRP injection, the transcription of prophenoloxidase genes in hemocytes was repressed, phenoloxidase activity in bacteria-challenged larval hemolymph was significantly decreased, and nodule formation in bacteria-injected larvae was reduced. More importantly, RNAi-treated insects infected with E. coli showed higher bacterial growth in hemolymph compared with infected controls. These results suggest that Ha-SRP gene plays importance roles in H. armigera innate immunity, possibly by mediating prophenoloxidase activation and nodulation response.
authors: Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan 430079, China.
authors: Chuan
authors: C
authors: Qiao
authors: Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan 430079, China.
authors: Jie
authors: J
authors: Li
authors: Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan 430079, China.
authors: Xiu-Hong
authors: XH
authors: Wei
authors: Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan 430079, China.
authors: Jia-Lin
authors: JL
authors: Wang
authors: Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan 430079, China.
authors: Yu-Feng
authors: YF
authors: Wang
authors: Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan 430079, China. Electronic address: xsliu@mail.ccnu.edu.cn.
authors: Xu-Sheng
authors: XS
authors: Liu
mesh_terms: D000818:Animals; D004156:Catechol Oxidase / Q000276:immunology / Q000378:metabolism*; D004789:Enzyme Activation / Q000235:genetics; D004792:Enzyme Precursors / Q000276:immunology / Q000378:metabolism*; D004926:Escherichia coli / Q000254:growth & development / Q000276:immunology*; D004927:Escherichia coli Infections / Q000276:immunology*; D005786:Gene Expression Regulation; D006434:Hemocytes / Q000276:immunology* / Q000382:microbiology; D007111:Immunity, Cellular; D007113:Immunity, Innate; D007915:Lepidoptera / Q000276:immunology*; D034741:RNA, Small Interfering / Q000235:genetics; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism*; D018000:Receptors, Peptide / Q000235:genetics / Q000378:metabolism*
chemical_list: D004792:Enzyme Precursors; D034741:RNA, Small Interfering; D018160:Receptors, Cytoplasmic and Nuclear; D018000:Receptors, Peptide; C036318:signal peptide receptor; C038451:pro-phenoloxidase; D004156:Catechol Oxidase
keywords: Helicoverpa armigera; Innate immunity; Nodulation; Prophenoloxidase activation; SRP