Epitranscriptomic modifications in plant RNAs

Abstract

A plethora of new and exciting findings have dramatically widened the horizons of plant RNA-related research. Despite being identified decades ago, RNA modifications were largely ignored owing to the immense difficulty in studying them with traditional methods. We now know that these chemical additions to RNA nucleotides affect a myriad of plant biological processes ranging from plant growth and development to stress responses. The field of epitranscriptomics, the study of RNA modifications, has been dominated by m⁶A in messenger RNAs (mRNAs), while modifications other than m⁶A remained largely unstudied. A recent increase in studies investigating other RNA modifications and the development of novel tools has added to the evolving landscape of plant epitranscriptomic research. As this non-m⁶A RNA modification research gathers pace, we use this review to provide a snapshot of the current state-of-the-art regarding these modifications with a focus on those occurring in functional non-coding RNAs as compared to mRNAs.

Keywords: RNA biology; RNA degradation; RNA modifications; RNA stability; epitranscriptome; plant RNA biology.

Figure 1.

A snapshot of RNA modifications and their roles in various RNA types. More than 170 different RNA modifications have been identified on various RNA species ranging from tRNAs to long non-coding RNAs. They affect RNA biology in varied ways including but not limited to altering RNA secondary structure and RNA turnover, ultimately affecting protein production, thus representing another potent layer of gene expression regulation.

Figure 2.

Conserved transfer RNA modifications. A majority of tRNA modifications identified so far have been found to be highly conserved across species. Modifications in important tRNA regions like the anti-codon loop and the TΨC loop are depicted in the figure.