Evolutionary Landscape of Tea Circular RNAs and Its Contribution to Chilling Tolerance of Tea Plant

作者：Jin Huang, Yanli Wang, Jie Yu, Fangdong Li, Lianghui Yi, Yunze Li, Na Xie, Qiong Wu, Lidiia Samarina, Wei Tong, Enhua Xia · 发表于：International Journal of Molecular Sciences · 年份：2023 · DOI：10.3390/ijms24021478 · 被引用次数：21 · 研究领域：Circular RNAs in diseases、Nitrogen and Sulfur Effects on Brassica

Chilling stress threatens the yield and distribution pattern of global crops, including the tea plant (Camellia sinensis), one of the most important cash crops around the world. Circular RNA (circRNA) plays roles in regulating plant growth and biotic/abiotic stress responses. Understanding the evolutionary characteristics of circRNA and its feedbacks to chilling stress in the tea plant will help to elucidate the vital roles of circRNAs. In the current report, we systematically identified 2702 high-confidence circRNAs under chilling stress in the tea plant, and interestingly found that the generation of tea plant circRNAs was associated with the length of their flanking introns. Repetitive sequences annotation and DNA methylation analysis revealed that the longer flanking introns of circRNAs present more repetitive sequences and higher methylation levels, which suggested that repeat-elements-mediated DNA methylation might promote the circRNAs biogenesis in the tea plant. We further detected 250 differentially expressed circRNAs under chilling stress, which were functionally enriched in GO terms related to cold/stress responses. Constructing a circRNA-miRNA-mRNA interaction network discovered 139 differentially expressed circRNAs harboring potential miRNA binding sites, which further identified 14 circRNAs that might contribute to tea plant chilling responses. We further characterized a key circRNA, CSS-circFAB1, which was significantly induced under chilling stress. FISH and s...