An Antisense Long Non-Coding RNA, LncRsn, Is Involved in Sexual Reproduction and Full Virulence in Fusarium graminearum

Fusarium head blight (FHB), primarily caused by <i>Fusarium graminearum</i>, is a devastating crop disease that leads to significant declines in wheat yield and quality worldwide. Long non-coding RNAs (lncRNAs) are found to play significant functions in various biological processes, but their regulatory functions in the sexual reproduction and pathogenicity of <i>F. graminearum</i> have not been studied extensively. This study identified an antisense lncRNA, named lncRsn, located in the transcription initiation site region between the 5'-flanking gene <i>FgSna</i> and the 3'-flanking gene <i>FgPta</i>. A deletion mutant of lncRsn (ΔlncRsn) was constructed through homologous recombination. ΔlncRsn exhibited huge reductions in pathogen and sexual reproduction. Additionally, the deletion of lncRsn disrupted the biosynthesis of deoxynivalenol (DON) and impaired the formation of infection structures. RT-qPCR analysis reveals that lncRsn may negatively regulate the transcription of the target gene FgSna. This study found that lncRsn plays an important role in sexual and asexual reproduction, pathogenicity, virulence, osmotic stress, and cell wall integrity (CWI) in <i>F. graminearum</i>. Further characterization of pathogenesis-related genes and the reaction between lncRsn and protein-coding genes will aid in developing novel approaches for controlling <i>F. graminearum</i> diseases.