Discovery and history of long noncoding RNAs in plants

Abstract Developments in the field of bioinformatics and genetics have opened avenues for the discovery of those transcriptional units which do not code for proteins. These RNA molecules are usually known as nonprotein coding RNAs or noncoding RNAs (npcRNAs or ncRNAs) and categorized on the basis of their length. Nonprotein-coding RNAs, which are greater than 200 nucleotides, are considered as long noncoding RNAs (lncRNAs). High-throughput techniques have been developed, which made it possible to look into the transcriptome of an organism to find out the lncRNAs. After the first discovery of lncRNAs in humans, there has been a hustle in the discovery of lncRNAs in plants. Glycine max was the first plant, which gave us the idea about lncRNAs in plants. Till now, a number of lncRNAs have been reported in various plant species. For instance, COOLAIR and COLDAIR in Arabidopsis thaliana and OsENOD40 and MtENOD40 in Oryza sativa and Medicago trunculata, respectively, have been identified as lncRNAs by various research groups. Initially, the lncRNAs were considered as junk RNA molecules; however, recent scientific explorations have unveiled their hidden diverse roles in plant development, stress tolerance, gene regulation, etc. Furthermore, the in-depth knowledge of lncRNAs will be useful for different crop improvement programs. In the present chapter, we have documented the history of lncRNAs’ discovery in various plant groups.