Kaiwen Liang

Comprehensive Utilization Center, Hainan Institute of Tropical Agricultural Resouces, Sanya, 572025, Hainan, China
Author    Correspondence author
Cotton Genomics and Genetics, 2025, Vol. 16, No. 5   doi: 10.5376/cgg.2025.16.0023
Received: 22 Jul., 2025    Accepted: 31 Aug., 2025    Published: 20 Sep., 2025

This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Liang K.W., 2025, Circular RNAs as molecular sponges modulating miRNA activity in cotton, Cotton Genomics and Genetics, 16(5): 232-240 (doi: 10.5376/cgg.2025.16.0023)

 

Circular RNAs (circRNAs) are a unique class of noncoding RNAs with covalently closed loop structures that play a crucial role in gene regulation in eukaryotes. In cotton (Gossypium spp.), microRNAs (miRNAs) are central to posttranscriptional gene regulation, influencing growth, development, and stress responses. This study investigates the role of circRNAs as molecular sponges in regulating miRNA activity in cotton. We first describe the biogenesis of circRNAs, their structural classification, and key features such as stability and tissue-specific expression. We then examine in detail the mechanisms by which circRNAs sequester miRNAs, including a competing endogenous RNA (ceRNA) network framework and experimental approaches to validate their sponging activity. We then highlight the regulatory roles of circRNAs in cotton fiber development, stress adaptation, and defense signaling through the circRNA-miRNA-mRNA axis. This study also reviews the progress in circRNA discovery using high-throughput sequencing and computational methods, as well as the challenges faced in their annotation. A key case study illustrates how specific circular RNAs act as "sponges" for miR156 and miR828, regulating SPL transcription factors and influencing fiber phenotype. Finally, we explore the potential of circular RNAs as biotechnological tools and molecular targets in cotton breeding programs. This study highlights the potential of circular RNA research for improving cotton quality and stress tolerance while also identifying knowledge gaps and future directions for multi-omics integration and genome editing strategies.

Circular RNA (circRNA); microRNA (miRNA) sponge; Cotton fiber development; Non-coding RNA regulation; Post-transcriptional gene regulation