Extrachromosomal circular DNA: A neglected nucleic acid molecule in plants.

Throughout the years, most plant genomic studies were focused on nuclear chromosomes. Extrachromosomal circular DNA (eccDNA) has largely been neglected for decades since its discovery in 1965. While initial research showed that eccDNAs can originate from highly repetitive sequences, recent findings show that many regions of the genome can contribute to the eccDNA pool. Currently, the biological functions of eccDNAs, if any, are a mystery but recent studies have indicated that they can be regulated by different genomic loci and contribute to stress response and adaptation. In this review, we outline current relevant technological developments facilitating eccDNA identification and the latest discoveries about eccDNAs in plants. Finally, we explore the probable functions and future research directions that could be undertaken with respect to different eccDNA sources.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)