RNA interference (RNAi) has emerged as a potent mechanism for combating pathogenic fungi and oomycetes over the past decades. It offers a promising gene-silencing approach by targeting crucial genes involved in diseases caused by economically and scientifically significant fungal pathogens, such as Botrytis cinerea and Fusarium species. Simultaneously, nano-agro-products have gained attention as alternatives to traditional fungicides in plant protection strategies. However, the instability of naked RNA molecules outside the cellular environment presents a challenge, as they degrade rapidly, limiting their efficacy for prolonged disease control. Concerns regarding the toxicity of protective nanoparticles to non-target organisms have also arisen. Integrating RNAi with nano-agro-products, particularly nanocarriers, to form RNA-nano complexes has demonstrated significant potential, providing enhanced RNA stability, reduced toxicity, and extended disease control. This review explores the mechanisms of RNA-nano complexes-mediated plant protection, addressing RNA stability and nano-toxicity issues while examining the prospects of RNA-nano complex research in plant pathogen management.

The virus–host interaction is dynamic and evolutionary. Viruses have to fight with hosts to establish successful infection. Eukaryotic hosts are equipped with multiple defenses against incoming viruses. One of the host antiviral defenses is the nonsense-mediated mRNA decay (NMD), an evolutionarily conserved mechanism for RNA quality control in eukaryotic cells. NMD ensures the accuracy of mRNA translation by removing the abnormal mRNAs harboring pre-matured stop codons. Many RNA viruses have a genome that contains internal stop codon(s) (iTC). Akin to the premature termination codon in aberrant RNA transcripts, the presence of iTC would activate NMD to degrade iTC-containing viral genomes. A couple of viruses have been reported to be sensitive to the NMD-mediated antiviral defense, while some viruses have evolved with specific cis-acting RNA features or trans-acting viral proteins to overcome or escape from NMD. Recently, increasing light has been shed on the NMD–virus interaction. This review summarizes the current scenario of NMD-mediated viral RNA degradation and classifies various molecular means by which viruses compromise the NMD-mediated antiviral defense for better infection in their hosts.