Decoding MicroRNA-Guided Antiviral Defense in Cucurbitaceae: Regulatory Networks, RNA Silencing Cross-Talk, and Emerging Strategies for Crop Resilience.

MicroRNAs (miRNAs) are central regulators of gene expression and play pivotal roles in plant antiviral defense. In Cucurbitaceae, a globally important crop family including cucumber, melon, and watermelon, viral pathogens such as CGMMV, CMV, and ZYMV represent major constraints on productivity. However, the regulatory complexity of miRNA-mediated antiviral responses in these species remains incompletely understood. This review provides an integrated overview of recent advances in miRNA-guided antiviral immunity in Cucurbitaceae, highlighting the dynamic reprogramming of small RNA pathways upon viral infection. Conserved miRNA families act as key regulatory hubs, controlling development, hormone signaling, and defense responses, while viral suppressors interfere with RNA silencing machinery, reshaping host regulatory networks. Emerging evidence further reveals multilayered interactions between miRNAs and other non-coding RNAs, including lncRNAs and circRNAs, indicating complex cross-talk that fine-tunes antiviral responses in a species- and virus-specific manner. Importantly, miRNAs exhibit a dual role by contributing both to antiviral defense and to symptom development. Advances in artificial miRNAs and RNA-based technologies underscore their potential for engineering durable virus resistance. Overall, miRNA-centered regulatory networks represent a promising target for next-generation crop protection strategies in Cucurbitaceae.