Nano-enabled RNAi strategies for sustainable citrus protection against viral pathogens

In conclusion, nanotechnology-assisted RNAi offers a promising and sustainable approach for managing citrus viral diseases through improved dsRNA stability and targeted delivery. Integration of HIGS and SIGS with advanced nanocarriers may enhance antiviral efficiency against diverse citrus pathogens. However, further studies on biosafety, large-scale application, and regulatory approval are essential for successful field implementation. Citrus production is severely constrained by virus and virus-like pathogens that reduce yield fruit quality, and orchard longevity, notably Citrus tristeza virus (CTV), Citrus psorosis virus (CPsV), Citrus vein enation virus (CVEV), Citrus yellow vein-clearing virus (CYVCV) and Citrus leaf blotch virus (CLBV), and emerging or regionally important agents, such as Citrus tatter leaf virus (CTLV), Indian citrus ringspot virus (ICRSV), and citrus yellow mosaic badnavirus (CYMV). Conventional management strategies, including certified planting material, vector suppression, and tolerant rootstock-based approaches, can reduce initial inoculum; however, they often fail to provide durable field-level protection in the presence of efficient vectors and complex virus diversity. RNA interference (RNAi) offers a sequence-specific antiviral approach yet its practical use in citrus is constrained by dsRNA degradation, limited penetration, and poor delivery. Nanotechnology-assisted carriers can improve RNA stability and delivery efficiency through protection and controlled release. This review summarizes citrus viral pathogens, RNA-silencing mechanism and viral suppressors, RNAi strategies (HİGS/SIGS), and nanocarrier design, and outlines key for translation, such as formulation stability, scale-up, and regulation.