Circular RNAs (circRNAs) are a kind of non-coding RNAs; they were first found over 35 years ago but have only become a research hotspot in recent years. CircRNAs are covalently closed loops derived from precursor mRNAs by non-sequential back-splicing. Based on their genomic location, circRNAs can be classified into exonic, intronic, intergenic, and exon-intronic circRNAs (Chen, 2016). By taking advantages of recent advances in bioinformatics algorithms, a large number of circRNAs have been detected among diverse organisms, including plants such as Arabidopsis thaliana and Oryza sativa (Memczak et al., 2013; Ye et al., 2015; Chen, 2016).