家蚕IMD信号通路对球孢白僵菌侵染的免疫应答反应  

Immune Response of IMD Signaling Pathway of Silkworm(Bombyx mori)to Beauveria bassiana Infection

作　　者：耿涛 涂娜娜 卢芙萍[1] 武华周 娄德钊 汪永松 王树昌[1] Geng Tao;Tu Nana;Lu Fuping;Wu Huazhou;Lou Dezhao;Wang Yongsong;Wang Shuchang(Environment and Plant Protection Institute,Chinese Academy of Tropical Agricultural Sciences,Haikou 571101,China;College of Tropical Crops,Hainan University,Haikou 570228,China;College of Plant Protection,Hainan University,Haikou 570228,China)

机构地区：[1]中国热带农业科学院环境与植物保护研究所,海口571101 [2]海南大学热带作物学院,海口570228 [3]海南大学植物保护学院,海口570228

出　　处：《蚕业科学》2020年第6期725-732,共8页ACTA SERICOLOGICA SINICA

基　　金：国家自然科学基金项目(31902217);海南省科协青年英才创新计划项目(QCXM201805);中央级公益性科研院所基本科研业务费专项(1630042019003);现代农业产业技术体系建设专项(CARS-18)。

摘　　要：IMD(immune deficiency)信号通路是调控昆虫体液免疫反应的重要信号转导途径之一。通过分析家蚕感染球孢白僵菌后IMD信号通路相关因子的表达模式,抑制剂阻断IMD信号通路对家蚕幼虫存活率、血淋巴抗真菌活性和抗真菌肽基因表达水平的影响,以及RNAi沉默IMD信号通路对家蚕抗真菌肽基因表达水平的影响,以期明晰IMD信号通路在家蚕抗真菌免疫应答中的作用。试验结果表明,家蚕感染球孢白僵菌后,IMD信号通路相关基因Bmimd、Bmtak 1、Bmdredd、Bmfadd和Bmrelish 1的表达显著上调,说明球孢白僵菌侵染家蚕能够激活IMD信号通路。用特异性抑制剂Parthenolide阻断IMD信号通路会显著降低家蚕幼虫存活率和血淋巴抗真菌活性,说明家蚕IMD信号通路参与抗真菌肽的合成。用抑制剂阻断家蚕幼虫IMD通路后,家蚕脂肪体中抗真菌肽基因Bmenbocin 1、Bmattacin 1和Bmgloverin 2的表达水平显著下调,而Bmcecropin A和Bmsp 30K-19G1基因的表达水平变化不显著;RNAi沉默BmN细胞的IMD信号通路得到相同的结果,说明IMD信号通路参与Bmenbocin 1、Bmattacin 1和Bmgloverin 2等抗真菌肽基因的表达调控。以上结果说明家蚕IMD信号通路可能通过上调Bmenbocin 1、Bmattacin 1和Bmgloverin 2等抗真菌肽基因的表达水平,提高家蚕幼虫血淋巴抗真菌活性,在家蚕抗真菌免疫应答反应中起到重要作用。Immune deficiency(IMD)signaling pathway is a critical immune signaling pathway in insects for humoral immune response.The expression pattern of signaling factors in IMD signaling pathway after Beauveria bassiana infection,the effects on survival rate of silkworm larvae,antifungal activity in hemolymph and expression levels of antifungal peptide genes after blocking IMD signaling pathway by inhibitor,the expression of antifungal peptide genes after knocked-down of IMD signaling pathway by RNAi,were analyzed to clarify the roles of IMD signaling pathway in antifungal immune response.As the experimental results indicated,expression of IMD signaling pathway related genes,Bmimd,Bmtak 1,Bmdredd,Bmfadd and Bmrelish 1,were significantly up-regulated after B.bassiana infection,suggesting that IMD signaling pathway was activated by B.bassiana.However,the survival rate of silkworm larvae and antifungal activity in hemolymph were all down-regulated after blocking IMD signaling pathway by specific inhibitor Parthenolide,which indicated that IMD signaling pathway was involved in the synthesis of antifungal peptides.Besides,expression of antifungal peptide related genes,Bmenbocin 1,Bmattacin 1 and Bmgloverin 2,were down-regulated after blocking IMD signaling pathway in silkworm larvae,while there was no change in the expression levels of Bmcecropin A and Bmsp 30K-19G1.RNAi assay in BmN cells showed the same results,which demonstrated that IMD signaling pathway was involved in expression regulation of Bmenbocin 1,Bmattacin 1 and Bmgloverin 2.These data indicated that IMD signaling pathway could increase the antifungal activity in hemolymph by up-regulating the expression levels of antifungal peptide genes(Bmenbocin 1,Bmattacin 1 and Bmgloverin 2),thus it played an important role in the silkworm antifungal immune response.

关 键 词：家蚕 IMD信号通路 球孢白僵菌 免疫应答 抗真菌肽 

分 类 号：S881.21[农业科学—特种经济动物饲养]