Approaches for identification and analysis of plant circular RNAs and their role in stress responses

CircularRNAs (circRNAs) comprise a large class of non-coding RNAs that lack free 3 ' and 5 ' ends, are covalently closed and produced by a non-canonical splicing event called backsplicing. Earlier circRNAs were regarded as worthless and called junk RNAs produced due to splicing errors but recent progress in circRNA research indicated their considerable roles in various biological processes. However, plant circRNA research is still in initial stages as compared to animal circRNAs. In this review, we have summarized the process of circRNA biogenesis, how plant circRNAs are different from animals, various modules that can be used for the identification of circRNAs and different circRNA databases. We have also provided an overview of recent progress on our understanding about the involvement of circRNA in various abiotic and biotic stress responses in plants. A proper understanding of the role of circRNAs in different aspects of plant development and stress response will provide novel ways to manipulate plants for their enhanced survivability and productivity in adverse climatic conditions.