Circular RNAs (circRNAs) are endogenous non-coding RNAs with covalently closed structures, which have important functions in plants. However, their biogenesis, degradation, and function upon treatment with gibberellins (GAs) and auxins (1-naphthaleneacetic acid, NAA) remain unknown. Here, we systematically identified and characterized the expression patterns, evolutionary conservation, genomic features, and internal structures of circRNAs using RNase R-treated libraries from moso bamboo (Phyllostachys edulis) seedlings. Moreover, we investigated the biogenesis of circRNAs dependent on both cis- and trans-regulation. We explored the function of circRNAs, including their roles in regulating microRNA (miRNA)-related genes and modulating the alternative splicing of their linear counterparts. Importantly, we developed a customized degradome sequencing approach to detect miRNA-mediated cleavage of circRNAs. Finally, we presented a comprehensive view of the participation of circRNAs in the regulation of hormone metabolism upon treatment of bamboo seedlings with GA and NAA. Collectively, our study provides insights into the biogenesis, function, and miRNA-mediated degradation of circRNAs in moso bamboo.

环状RNA（circRNA）是具有共价闭合结构的内源非编码RNA，在植物中具有重要的功能。然而，它们的生物发生、降解以及用赤霉素（GA）和生长素（1-萘乙酸，NAA）处理后的功能仍然未知。在这里，我们使用来自毛竹（Phyllostachys edulis）幼苗的 RNase R 处理文库系统地鉴定和表征了 circRNA 的表达模式、进化保守性、基因组特征和内部结构。此外，我们研究了依赖顺式和反式调节的 circRNA 的生物发生。我们探索了 circRNA 的功能，包括它们在调节 microRNA (miRNA) 相关基因和调节其线性对应物的选择性剪接中的作用。重要的是，我们开发了一种定制的降解组测序方法来检测 miRNA 介导的 circRNA 切割。最后，我们全面介绍了 GA 和 NAA 处理竹苗后 circRNA 参与激素代谢调节的情况。总的来说，我们的研究提供了对毛竹中 circRNA 的生物发生、功能和 miRNA 介导的降解的见解。