[Progress in circular RNAs of plants]

Circular RNAs (circRNAs) are covalently closed, conserved single-stranded transcripts that are produced from precursor mRNA (pre-mRNA) back-splicing. They could function as microRNA sponges, interfere with splicing and bind to protein to regulate the expression of parental genes and linear mRNAs. Next-generation RNA sequencing (RNA-seq) has recently shown that the expression of circRNAs is widespread in plants. circRNAs participate in multiple biological processes such as floral development, fruit ripening, and biotic and abiotic stress responses by cell type-specific and tissue-specific expression patterns, indicating that they may play an important role in plant development. In this review, we summarize the current knowledge of plant circRNAs in recent years, including the biogenesis, detection, databases, expression pattern, and potential functions in comparison with animal results to provide new insights for functional research interests of circRNAs in the future.