Bt对棉铃虫天蚕素抗菌肽基因(HacD)转录的影响  

Effects of Bt induced immune sensitization on cotton bollworm(Helicoverpa armigera)in relation to the cecropin(HacD)expression

作　　者：袁伟宁 魏玉红[1,2] 郭建国 刘月英[1,2] 张美娇 郭致杰[1,2] YUAN Weining;WEI Yuhong;GUO Jianguo;LIU Yueying;ZHANG Meijiao;GUO Zhijie(Institute of Plant Protection,Gansu Academy of Agricultural Sciences,Gansu Engineering Research Center for Natural Enemies of Agricultural Pests,Lanzhou 730070,China;Scientific Observing and Experimental Station of Crop Pests in Tianshui,Ministry of Agriculture and Rural Affairs,Tianshui 741200,China)

机构地区：[1]甘肃省农业科学院植物保护研究所,甘肃省农业害虫天敌工程研究中心,兰州730070 [2]农业农村部天水作物有害生物科学观测实验站,天水741200

出　　处：《植物保护》2024年第4期161-167,共7页Plant Protection

基　　金：甘肃省农业科学院农业科技创新中青年基金(2021GAAS44);甘肃省科技厅重点研发计划(20YF8NA108)。

摘　　要：抗菌肽是昆虫体液免疫的重要组成部分,对抵御外源致病微生物的侵染具有重要作用。明确苏云金芽胞杆菌Bacillus thuringiensis(Bt)诱导下棉铃虫天蚕素抗菌肽基因(HacD)转录的空间特征和时序特征,有利于进一步了解昆虫体液免疫与棉铃虫抗Bt发展的关联性。本研究测定了HacD cDNA序列,对序列进行了蛋白质翻译,并通过RT-qPCR技术研究了棉铃虫HacD基因在Bt诱导下的转录规律。结果表明,棉铃虫HacD cDNA全长189 bp,其中GC含量为48.15%,肽链由63个氨基酸组成。Bt诱导后棉铃虫幼虫HacD相对转录水平整体呈显著上调趋势,其中脂肪体中HacD的相对转录水平上调最高,其次为血淋巴。Bt对棉铃虫幼虫进行短期诱导后,脂肪体和血淋巴中的HacD基因的相对转录水平均呈持续上调趋势,分别在诱导24 h和18 h时达到最高,随后均持续下调。对幼虫进行持续诱导后,F 0代初孵幼虫、5龄幼虫、蛹和成虫的HacD基因均可以保持上调的转录特性;传代培养获得的F 1代初孵幼虫、5龄幼虫、蛹和成虫的HacD基因转录较F 0代下调,但均高于对照组。综上所述,Bt能够诱导棉铃虫HacD基因转录水平上调。Antimicrobial peptides constitute a crucial aspect of insect humoral immunity,playing a vital role in combating exogenous pathogenic microorganisms.Understanding the spatial and temporal dynamics of antimicrobial peptide gene transcription,such as HacD in the cotton bollworm induced by Bacillus thuringiensis(Bt),is pivotal to elucidating the correlation between insect humoral immunity and the development of resistance to Bt in cotton bollworm.In this study,the sequence of HacD cDNA was obtained,its protein was translated,the transcriptional pattern of the HacD gene in cotton bollworm under Bt induction was studied by RT-qPCR.The results showed that the HacD cDNA of cotton bollworm was 189 bp in length,with a GC content of 48.15%,resulting in a peptide chain consisting of 63 amino acids.The relative transcript levels of HacD were significantly up-regulated in cotton bollworm larvae after Bt induction,with the highest level in fat body,followed by the hemolymph.After short-term Bt induction,the relative transcript levels of HacD genes were continuously up-regulated in both fat body and hemolymph,reached the highest level when induced for 24 h and 18 h,respectively,and then gradually declining.Furthermore,continuous induction to larvae led to a maintaining up-regulation of transcriptional levels of HacD genes across various developmental stages,including neonate larvae,the 5th-instar larvae,pupae,and adults in F 0 generation.The transcript levels of HacD genes in F 1 generation individuals came from F 0 generation displayed a down-regulated trend compared to those in F 0 generation,but all were higher than those in the control group.In summary,Bt can cause up-regulation of HacD gene transcription level in cotton bollworm.

关 键 词：棉铃虫 苏云金芽胞杆菌 免疫致敏 抗性 抗菌肽 脂肪体 

分 类 号：S435.622.3[农业科学—农业昆虫与害虫防治]