Identification of ceRNA-vsiRNA-mRNA network for exploring the mechanism underlying pathogenesis of sugarcane mosaic virus in resistant and susceptible maize inbred lines

Abstract RNA silencing plays an important role in plant antiviral responses, which trigger the production of virus-derived small interfering RNAs (vsiRNAs). The competing endogenous RNA (ceRNA) hypothesis revealed a unique mechanism in which circular RNAs (circRNAs) and long non-coding RNAs (lncRNAs) can interact with small RNAs to regulate the expression of corresponding target mRNAs. Sugarcane mosaic virus (SCMV) infection causes severe economic losses in maize ( Zea mays L.) production worldwide. This study compared and analyzed characteristics of vsiRNAs derived from SCMV and their target genes in resistant (Chang7-2) and susceptible (Mo17) maize inbred lines through whole-transcriptome RNA sequencing and degradome sequencing. The results showed that 706 transcripts were targeted by 204 vsiRNAs, including 784 vsiRNA-target gene pairs. Furthermore, ceRNA networks of circRNA/lncRNA-vsiRNA-mRNA in response of maize to SCMV infection were obtained, including 3 differentially expressed (DE) circRNAs, 36 DElncRNAs, 105 vsiRNAs, and 342 DEmRNAs in Mo17 plants, and 3 DEcircRNAs, 35 DElncRNAs, 23 vsiRNAs, and 87 DEmRNAs in Chang7-2 plants. Our results also showed that the transcripts of ZmDCLs , ZmAGOs , and ZmRDRs were differentially accumulated in resistant and susceptible maize inbred lines after SCMV infection. These findings provide valuable insights into the relationship between SCMV-derived vsiRNAs and potential ceRNAs fine-tuning the SCMV-maize interaction and offer novel clues to reveal the mechanism underlying the pathogenesis of SCMV.