Identification of tomato circular RNAs in response to Botrytis cinerea

Botrytis cinerea is one of the main pathogens that harm the tomato yield and cause huge economic losses worldwide. Studies of circRNAs in response to the stress caused by pathogens have received more and more attention in tomato and other model crops. In this study, four groups were treated with ZaoFen (ZF), CuiLi (CL) (susceptible and tolerant genotypes to B. cinerea, respectively), ZFBc, CLBc (48 hour response to a B. cinerea infection). A total of 918 circRNAs were identified, among which exonic circRNAs (70.70%) accounted for the majority of them, and 118 circRNAs (12.85%) were located in chr1. A total of 18 (1.96%) circRNAs were shared among the four libraries. A total of 6 circRNAs showed fold changes in the differential expression analysis between the time and cultivar control groups, and circRNA115, circRNA145 and circRNA223 repeatedly appeared in the different control treatments. Notably, the gene targeted by circRNA115 was an ethylene-forming enzyme. At the same time, we predicted the target genes of the six circRNAs obtained in the study, and a total of 319 miRNAs were predicted. This study contributes to the mechanism in response to B. cinerea stress in the tomato, and paves the way for the further study of circRNAs under tomato pathogen stress.