Express delivery: dsRNA applications and RNAi nanocarrier systems to combat potato late blight

Abstract

Phytophthora late blight remains one of the most devastating diseases of potatoes, posing persistent challenges to global food security and sustainable agriculture. Although RNA interference (RNAi) has emerged as a powerful and highly specific strategy for pathogen control, its practical application against P. infestans has largely remained at the proof-of-concept stage. This limitation does not result from a lack of suitable gene targets, but rather from challenges associated with the delivery, stability, and uptake of RNA molecules under field conditions. In this review, we outline current advances in RNAi-based approaches for the control of P. infestans, with a particular focus on spray-induced gene silencing (SIGS) and the potential of nanocarrier-based delivery systems. We summarize proof-of-concept studies targeting essential oomycete genes, discuss the molecular mechanisms underlying double-stranded RNA (dsRNA) uptake in plants and oomycetes, and critically evaluate the strengths and limitations of host-induced gene silencing (HIGS) and SIGS. Unlike recent reviews on nanocarrier-mediated RNA delivery, this manuscript provides a system-specific focus centered on the potato–P. infestans pathosystem and the unique biological features of the plant–oomycete interface. Central to this review is the argument that future success of RNAi-based disease management will require systems‑level optimization that integrates target selection, dsRNA design, formulation, delivery, and application timing, while emphasizing that delivery remains a major bottleneck for translation to field applications. We highlight how nanocarriers can enhance dsRNA stability, improve adhesion and cellular uptake, and enable controlled release, thereby transforming SIGS into a robust and environmentally sustainable plant protection strategy. Finally, we position RNAi-based nanobiopesticides within the broader European regulatory and sustainability landscape, emphasizing both regulatory feasibility and the importance of public trust and societal acceptance. Together, these insights position nanocarrier-enabled SIGS as a promising cornerstone of next-generation, sustainable late blight management.