甜瓜circRNA及其蔓枯病抗性靶基因鉴定

Identification of circRNA and their target genes related to resistance to gummy stem blight in melon

[目的]本文旨在通过甜瓜接种蔓枯病菌前、后circRNA的研究及靶基因的筛选验证,探究circRNA在甜瓜抗蔓枯病过程中的作用。[方法]利用感病品种‘白皮脆’和抗病材料PI420145,分别在接种前、后取样,构建circRNA文库,通过RNA-Seq、Real-time PCR验证以及基因结构分析,探索circRNA在抗蔓枯病过程中的作用。[结果]12个circRNA文库中共鉴定出3136个circRNA,过滤后共获得1511个circRNA。聚类分析结果表明,circRNA的种类和表达具有品种差异性,且接种蔓枯病菌会引起circRNA的变化。接种蔓枯病菌前、后,在PI420145和‘白皮脆’中分别筛选到4个和3个差异表达的circRNA,其中1个circRNA在2种材料中都有差异表达;对6个靶标基因的结构域分析及RT-qPCR分析结果表明,MELO3C022310、MELO3C002560和MELO3C010763基因与甜瓜蔓枯病抗性相关。[结论]circRNA参与了甜瓜材料PI420145对蔓枯病入侵的防御反应。

[Objectives]The purpose of this article was to investigate the role of circRNA involved in the resistance of melon to gummy stem blight through the study of circRNA and screening of target genes before and after the inoculation of Didymella bryoniae.[Methods]The circRNA libraries were constructed by sampling the susceptible variety‘Baipicui’and disease-resistant material PI420145 before and after inoculation,respectively.The RNA-Seq,real-time PCR and gene structure analysis were combined to explore the role of circRNA in the resistance to gummy stem blight.[Results]A total of 3136 circRNA were identified from 12 libraries,and 1511 circRNA were resultantly obtained after filtering.Through cluster analysis,it was concluded that the types and expression of circRNA were various among different cultivars and could be changed by the inoculation of D.bryoniae.Before and after inoculation,4 and 3 differentially expressed circRNA were screened in PI420145 and‘Baipicui’,respectively,and one of which was differentially expressed in both materials.The results of domain analysis and RT-qPCR of the 6 target genes showed that the genes of MELO3C022310,MELO3C002560 and MELO3C010763 were related to resistance of melon gummy stem blight.[Conclusions]The circRNA was involved in the defense response of melon source PI420145 to the invasion of D.bryoniae.