Rice is exposed to attacks by the three most destructive pathogens, Magnaporthe oryzae (M. oryzae), Xanthomonas oryzae pv. oryzae (Xoo), and Rhizoctonia solani (R. solani), which cause substantial yield losses and severely threaten food security. To cope with pathogenic infections, rice has evolved diverse molecular mechanisms to respond to a wide range of pathogens. Among these strategies, plant microRNAs (miRNAs), endogenous single-stranded short non-coding RNA molecules, have emerged as promising candidates in coordinating plant–pathogen interactions. MiRNAs can modulate target gene expression at the post-transcriptional level through mRNA cleavage and/or translational inhibition. In rare instances, they also influence gene expression at the transcriptional level through DNA methylation. In recent years, substantial advancements have been achieved in the investigation of microRNA-mediated molecular mechanisms in rice immunity. Therefore, we attempt to summarize the current advances of immune signaling mechanisms in rice–pathogen interactions that are regulated by osa-miRNAs, including their functions and molecular mechanisms. We also focus on recent findings concerning the role of osa-miRNAs that respond to M. oryzae, Xoo, and R. solani, respectively. These insights enhance our understanding of how the mechanisms of osa-miRNAs mediate rice immunity and may facilitate the development of improved strategies for breeding pathogen-resistant rice varieties.

As the primary cash crop for natural fiber, cotton develops under sophisticated endogenous genetic programs, with biotic and abiotic stresses continuously driving its adaptive evolution. MicroRNAs (miRNAs) are post-transcriptional regulators that modulate gene expression via target mRNA cleavage, translational repression, and mediation of DNA methylation. miRNAs target transcription factors and hormone signaling pathways to regulate cotton plant architecture and fiber development. In addition, miRNAs mitigate biotic and abiotic stresses through ROS, lignin, and hormone pathways, as well as by forming competing endogenous RNA (ceRNA) modules with long noncoding RNAs (lncRNAs). This review establishes an miRNA-centered regulatory framework that coordinates cotton growth, development, and stress resistance. A series of technologies, including multi-omics combined with machine learning, gene overexpression, STTM, MIM, MIGS, CRISPR editing, foliar dsRNA spraying, and bionanocarriers, are proposed to facilitate the breeding of cotton varieties with high yield, superior fiber quality, and broad-spectrum stress tolerance.