Recent Advances and Emerging Applications of Small <scp>RNA</scp> Technologies in Plant Disease Resistance: A Narrative Review

ABSTRACT Humans, animals and plants are constantly exposed to pathogens and pests, leading to serious threats to global health and crop productivity. RNA interference (RNAi), mediated by small RNAs (sRNAs), is a conserved regulatory mechanism across eukaryotes that plays a key role in host immunity and pathogen virulence. In plants, diseases significantly impact yield and quality, intensifying the need for ecofriendly crop protection strategies. sRNAs, such as microRNAs (miRNAs) and small interfering RNAs (siRNAs), regulate gene expression through transcriptional and post‐transcriptional silencing. Specific sRNAs, including miRNAs and trans‐acting siRNAs (ta‐siRNAs), primarily suppress gene expression post‐transcriptionally by directing mRNA cleavage or inhibiting translation. This targeted mRNA degradation prevents the production of proteins crucial for pathogen survival or virulence, thereby enhancing plant immunity. sRNAs also regulate plant growth, development, reproduction and stress responses. A significant advancement is host‐induced gene silencing (HIGS), where plants are engineered to produce siRNAs that silence essential pathogen genes, effectively reducing infections. Recent research has highlighted the role of noncoding sRNAs from both plants and pathogens in shaping host–pathogen interactions. These sRNAs can move between organisms, enabling trans‐kingdom gene silencing—a promising frontier in crop protection. Plant‐derived sRNAs can be designed to target and silence pathogenicity genes, offering a sustainable approach to disease control. This review emphasises the latest insights into sRNA function and mobility, highlighting their potential in enhancing crop resistance and advancing agricultural biotechnology. Through these innovations, RNAi‐based methods offer a novel and effective strategy for improving plant health and securing global food supplies.