Genome-wide identification and characterization of circRNAs in wheat tiller

https://link.springer.com/article/10.1007/s00122-023-04277-2

Theoretical and Applied Genetics，136, Article number:102(2023)

Fangkun Wu,Zhiqiang Wang,Wanlin Zhou,Yan Liu,Haoran Shi,Xiangjian Gou,Haojie Li,Yu Lin,Caixia Li&Yaxi Liu

Key message

This study found that the intergenic circRNAs of wheat were more abundant than those of other plants. More importantly, a circRNA-mediated network associated with tillering was constructed for the first time.

Abstract

Circular RNAs (circRNAs) are a class of endogenous non-coding RNAs with covalently closed circular structures, which play an important role in transcriptional and post-transcriptional regulation. Tiller is an important agronomic trait that determines plant morphological architecture and affects spike number in wheat. However, no studies on the characteristics and functions of circRNAs involved in the regulation of wheat tiller. Here, we performed a genome-wide identification of circRNAs using ribosomal-depleted RNA-seq from wheat tiller of two pairs near-isogenic lines. A total of 686 circRNAs were identified and distributed on 21 chromosomes of wheat, of which 537 were novel circRNAs. Unlike other plants, the majority of these circRNAs (61.8%) were derived from intergenic regions. One circRNA-mediated network associated with tillering was constructed through weighted gene co-expression network analysis, including 323 circRNAs, 117 miRNAs, and 968 mRNAs. GO and pathway enrichment analysis of mRNAs suggested that these circRNAs are involved in cell cycle, ncRNA export from nucleus, developmental process, plant hormone signal transduction, MAPK signaling pathway, RNA degradation. Of these circRNAs, ten circRNAs are associated with known tillering/branching genes in rice orArabidopsis thaliana, includingOsCesA7,EBR1,DTE1,CRD1,LPA1,PAY1,LRK1,OsNR2,OsCCA1,OsBZR1. In summary, we present the first study of the identification and characterization of circRNAs in wheat tiller, and the results suggest these circRNAs associated with tillering could play an important role in wheat tiller formation and development.