Exonic Circular RNAs Are Involved in Arabidopsis Immune Response Against Bacterial and Fungal Pathogens and Function Synergistically with Corresponding Linear RNAs

Elucidating circRNA-miRNA-mRNA competing endogenous regulatory RNA network during leaf rust pathogenesis in wheat (Triticum aestivum L.)

Advancements in bioinformatic tools and breakthroughs in high throughput RNA sequencing have unveiled the potential role of non-coding RNAs in influencing the overall expression of disease-responsive genes. Owing to the increasing need to develop resilient crop varieties against environmental constraints, our study explores the functional relationship of various non-coding RNAs in wheat during leaf rust pathogenesis. MicroRNAs (miRNAs) and circular RNAs (circRNAs) were retrieved from SAGE and RNA-Seq libraries, respectively, in the susceptible (HD2329) and resistant (HD2329 + Lr28) wheat Near-Isogenic Lines (NILs). Here we explored the previously published circRNAs for their differential expression and correlated the data with the differentially expressed miRNAs (DEMs) through various in silico methods to acquire the target miRNAs of circRNAs and the downstream target mRNAs of miRNAs. Finally, a competing endogenous RNA (ceRNAs) regulatory network was constructed and validated through RT-qPCR method. We have identified the ceRNA regulatory network of four differentially expressed circRNAs (DECs) and five DEMs to highlight their crucial roles in the robust enhancement of the temporal expression profiles of five defense responsive genes (mRNAs) in wheat NILs against leaf rust infection. The study confirms the synergistic expression of circRNAs and mRNAs with an antagonistic correlation with the expression profile of the corresponding miRNAs. The vital role of leaf rust-resistant gene Lr28 has also been highlighted for driving the efficiency of the circRNAs to upregulate target gene expression. Thus, understanding the circRNA-miRNA-target gene interaction during leaf rust pathogenesis can help to identify stress-specific regulatory biomarkers to enhance defense responses in wheat for improved resilience through multi-omics integration of transcriptomics, proteomics and metabolomics.

Advances in CircRNAs in the Past Decade: Review of CircRNAs Biogenesis, Regulatory Mechanisms, and Functions in Plants

Circular RNA (circRNA) is a type of non-coding RNA with multiple biological functions. Whole circRNA genomes in plants have been identified, and circRNAs have been demonstrated to be widely present and highly expressed in various plant tissues and organs. CircRNAs are highly stable and conserved in plants, and exhibit tissue specificity and developmental stage specificity. CircRNAs often interact with other biomolecules, such as miRNAs and proteins, thereby regulating gene expression, interfering with gene function, and affecting plant growth and development or response to environmental stress. CircRNAs are less studied in plants than in animals, and their regulatory mechanisms of biogenesis and molecular functions are not fully understood. A variety of circRNAs in plants are involved in regulating growth and development and responding to environmental stress. This review focuses on the biogenesis and regulatory mechanisms of circRNAs, as well as their biological functions during growth, development, and stress responses in plants, including a discussion of plant circRNA research prospects. Understanding the generation and regulatory mechanisms of circRNAs is a challenging but important topic in the field of circRNAs in plants, as it can provide insights into plant life activities and their response mechanisms to biotic or abiotic stresses as well as new strategies for plant molecular breeding and pest control.

Non-coding RNAs in gynecologic cancer

The term "gynecologic cancer" pertains to neoplasms impacting the reproductive tissues and organs of women encompassing the endometrium, vagina, cervix, uterus, vulva, and ovaries. The progression of gynecologic cancer is linked to various molecular mechanisms. Historically, cancer research primarily focused on protein-coding genes. However, recent years have unveiled the involvement of non-coding RNAs (ncRNAs), including microRNAs, long non-coding RNAs (LncRNAs), and circular RNAs, in modulating cellular functions within gynecological cancer. Substantial evidence suggests that ncRNAs may wield a dual role in gynecological cancer, acting as either oncogenic or tumor-suppressive agents. Numerous clinical trials are presently investigating the roles of ncRNAs as biomarkers and therapeutic agents. These endeavors may introduce a fresh perspective on the diagnosis and treatment of gynecological cancer. In this overview, we highlight some of the ncRNAs associated with gynecological cancers.

Identification, biogenesis, function, and mechanism of action of circular RNAs in plants

Circular RNAs (circRNAs) are a class of single-stranded, closed RNA molecules with unique functions that are ubiquitously expressed in all eukaryotes. The biogenesis of circRNAs is regulated by specific cis-acting elements and trans-acting factors in humans and animals. circRNAs mainly exert their biological functions by acting as microRNA sponges, forming R-loops, interacting with RNA-binding proteins, or being translated into polypeptides or proteins in human and animal cells. Genome-wide identification of circRNAs has been performed in multiple plant species, and the results suggest that circRNAs are abundant and ubiquitously expressed in plants. There is emerging compelling evidence to suggest that circRNAs play essential roles during plant growth and development as well as in the responses to biotic and abiotic stress. However, compared with recent advances in human and animal systems, the roles of most circRNAs in plants are unclear at present. Here we review the identification, biogenesis, function, and mechanism of action of plant circRNAs, which will provide a fundamental understanding of the characteristics and complexity of circRNAs in plants.