Transcriptome and small RNA sequencings reveal the response of tobacco to aphid infestation.

Aphids threaten many economically important crops by extracting plant sap and efficiently transmitting plant viruses. To elucidate the molecular mechanisms underlying plant-aphid interactions, we performed mRNA, circRNA, and microRNA sequencing to investigate the response of tobacco plants to infestation by the aphid Myzus persicae. Our results revealed that aphid infestation significantly upregulated 1,091 genes and downregulated 407 genes. Notably, differentially expressed genes were enriched in several key pathways, including the MAPK signaling pathway, α-linolenic acid metabolism, glutathione metabolism, and plant-pathogen interactions. Analysis of circRNA expression identified 53 circRNAs with significant changes following aphid infestation. However, neither their predicted miRNA targets nor their host genes exhibited altered expression levels, suggesting that circRNAs may play previously uncharacterized roles in plant responses to aphid attack. Approximately 400 miRNAs were predicted in each library, with nearly two-thirds identified as novel. Among them, 22 miRNAs were differentially expressed in response to aphid infestation, but only 8 were predicted to target mRNAs, indicating a selective role of miRNAs in regulating gene expression during the aphid response. In summary, our findings shed light on the transcriptional and post-transcriptional regulatory mechanisms activated in tobacco during aphid infestation. Our findings provide a basis for future studies of aphid-responsive regulatory mechanisms in plants.