Genetius

The study reveals that vesicle trafficking components can both promote and restrict geminiviral infection in Nicotiana benthamiana. Using virus-induced gene silencing of eight trafficking regulators, silencing of NbSAR1 and NbAP-1γ enhanced systemic geminiviral DNA accumulation, whereas silencing of Nbδ‑COP, NbARF1, and clathrin genes nearly eliminated infection without affecting viral replication. These effects were specific to geminiviruses and suggest that endocytosis and retrograde transport are essential for systemic spread, while vacuolar/autophagy pathways may mediate antiviral defense.

Silencing polyphenol oxidase (PPO) in Nicotiana benthamiana via agroinfiltration prevents oxidative browning and the cross‑linking of native proteins such as RuBisCo, without affecting plant growth. The reduction of PPO activity also appears to improve transient gene expression, suggesting a valuable strategy for plant‑based molecular pharming.

The study engineered a tobacco rattle virus (TRV) vector to deliver artificial microRNAs and synthetic trans-acting siRNAs from minimal precursors, achieving robust and specific silencing of endogenous genes in Nicotiana benthamiana. Delivery via foliar spray of TRV crude extracts provided a transgene‑free, symptom‑minimal platform that also conferred strong resistance to tomato spotted wilt virus.

The study used agroinfiltration and virus‑induced gene silencing (VIGS) in Nicotiana benthamiana to knock down 21 immunity‑related genes and assess their impact on transient GFP expression. Silencing of EIN2, CERK1, NPR1, and ICS markedly enhanced GFP accumulation, and a npr1a/npr1b double mutant confirmed the role of NPR1 in suppressing transient protein expression.