Genetius

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 introduces a live confocal imaging method for observing microtubule and actin dynamics during pollen mitosis I in Nicotiana benthamiana bicellular pollen using suspension cultures and biolistic DNA delivery. Pharmacological experiments reveal that actin filaments are essential for nuclear positioning, cell plate expansion, and chromatin dispersion, while microtubule disruption leads to chromosome segregation defects. This in vitro system highlights the distinct roles of cytoskeletal components in asymmetric pollen division and differentiation.

The study generated loss‑of‑function prf mutants in Nicotiana benthamiana and showed that autoactive tomato NRC proteins still trigger hypersensitive cell death without Prf, demonstrating a unidirectional dependency of sensor NLRs on helper NRCs. The same autoactive NRCs also induced cell death when transiently expressed in lettuce, which lacks a Prf ortholog, highlighting the utility of N. benthamiana and lettuce for dissecting NLR network interactions.

The authors created a synthetic, wound‑induced transcriptional cascade that activates developmental regulator genes to generate de novo meristems in planta, enabling transgenic and CRISPR‑mediated gene editing without tissue‑culture steps. Using WIND1 to drive ESR1‑controlled DR expression, they induced meristematic activity in Nicotiana benthamiana internodes, achieving knockout of the phytoene desaturase gene, and successfully extended the system to tomato and soybean.

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.