Role of Circular RNAs (circRNAs) in Environmental Stress Response: Beyond Linear Understanding

circRNAs are closed and single-stranded RNA molecules and their expression encompasses the archaea, prokaryotes, as well as eukaryotes. circRNAs have greater structural diversity and stability and are involved in inhibition of the binding of miRNAs to target genes which causes lower expression of the target genes, apoptosis, and drug resistance. In this way, circRNAs control various functions including transcriptional regulation, protein translation, miRNA sponging, redistributing or translocating proteins, altering interactions among proteins, and formation of circRNA-protein-mRNA ternary complexes. This chapter provides an overview of biogenesis of circRNAs, their origin and classification, diversity in structure, their functional mechanisms. Further, this chapter explores their function in plants, roles in their growth and development, defense mechanisms, and their applications through emphasis on genetic manipulation approaches, thus, providing information on bioinformatics resources and databases available for circRNA research.