Non-coding RNAs as convergent control hubs integrating abiotic and biotic stress responses in crops

Non-coding RNAs (ncRNAs) have emerged as central regulators of how plants perceive, integrate, and respond to environmental and biological challenges. Once regarded as transcriptional noise, diverse ncRNA classes, including microRNAs (miRNAs), small interfering RNAs (siRNAs), long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), enhancer RNAs (eRNAs), and piwi-interacting RNA (piRNAs), are now recognized as powerful modulators of gene regulatory networks that shape stress signalling, developmental plasticity, and immune competence. Acting across epigenetic, transcriptional, and post-transcriptional levels, ncRNAs orchestrate chromatin remodelling, RNA stability, redox homeostasis, and hormone signalling to balance growth and defense. This review synthesizes evidence that ncRNA-mediated regulation is highly convergent: identical ncRNA modules are repeatedly recruited across abiotic and biotic stresses and funnel diverse signals through shared regulatory nodes involving hormone networks, reactive oxygen species, and master transcriptional hubs. We highlighted how redox-ncRNA feedback loops, chromatin-embedded ncRNA activity, and cross-layer interactions among miRNAs, siRNAs, lncRNAs, and circRNAs generate synergistic control over stress responses. This review further discusses how ncRNAs encode stress memory and priming, enabling plants to respond more efficiently to recurrent challenges, while also imposing regulatory trade-offs that constrain growth, development, and yield. Despite rapid discovery, ncRNA research remains limited by incomplete mechanistic validation, uncertain epigenetic stability, weak integration with systems biology, and unresolved biosafety and regulatory issues. Addressing these barriers will be essential for translating ncRNA biology into predictive and deployable strategies. By leveraging their capacity to unify signalling and adaptive regulation, ncRNAs represent promising molecular entry points for developing resilient, climate-ready crops.