Rnai-based vaccination technology for protecting crops against tomato spotted wilt virus

Overview

This solution offers an RNA interference (RNAi)-based vaccination strategy for protecting crops against tomato spotted wilt virus (TSWV), a membrane-encapsidated, negative-sense RNA virus responsible for severe yield losses worldwide. The approach involves the exogenous application of double-stranded RNA (dsRNA) molecules containing sequences from the TSWV genome, which trigger the plant's natural RNA silencing machinery to suppress viral replication. Preliminary validation in the model plant Nicotiana benthamiana demonstrated that dsRNA targeting the viral N gene drastically reduced local lesion formation and kept 54% of treated plants asymptomatic and virus-free for up to 40 days post-inoculation. This represents the first evidence that RNAi vaccination can be effective against complex negative-sense RNA plant viruses, opening a new frontier in sustainable plant disease management.

Technical specifications

• Mechanism of action: Exogenous dsRNA molecules are taken up by plant cells and processed by the RNA interference pathway, silencing complementary viral RNA sequences.
• Target selection: Two genomic regions were evaluated—the N gene (nucleocapsid protein) and the NSm gene (movement protein). The N-targeting dsRNA showed strong protective efficacy, while the NSm-targeting dsRNA did not provide protection.
• Validation in model plants: In N. benthamiana, plants treated with TSWV plus N-targeting dsRNA showed drastically reduced local lesion counts compared to controls. Systemic symptoms including chlorosis, necrosis, stunting, and wilting were monitored up to 40 days post-inoculation.
• Key results: 54% of plants receiving T+dsN treatment remained asymptomatic and virus-free, while no protection was observed in plants treated with TSWV alone or with NSm-targeting dsRNA.
• Next-stage development: Plans to test the technology on economically important crops including tomato, pepper, and chrysanthemum, and to improve dsRNA stability through conjugation with chitosan nanoparticles in collaboration with the Politecnico di Torino.

Technology readiness level

The technology is at an early-to-mid stage of development (TRL 3–4). Proof-of-concept has been demonstrated in a model plant system under controlled conditions, with clear evidence of protective efficacy. Future validation will extend testing to crop species susceptible to TSWV, measure the duration of the protective effect in dedicated glasshouse experiments, and improve dsRNA stability for potential field or greenhouse application. Further development is needed to optimize formulation, delivery methods, and field performance before commercial deployment.