Genetius

The study demonstrates that the Nicotiana benthamiana NLR Roq1, previously known to recognize the XopQ/HopQ1/RipB effector family, also detects the structurally distinct HopAG1 effector, leading to reduced bacterial growth and disease symptoms. Roq1-HopAG1 interaction was confirmed by co‑immunoprecipitation and attributed to the Nudix domain of HopAG1 binding a similar receptor interface as XopQ, suggesting broader effector recognition potential for Roq1 and other TNLs.

The study demonstrates that infiltrating Nicotiana benthamiana leaves with specific nopaline-type Agrobacterium tumefaciens strains dramatically increases local glandular trichome density within 15 days, an effect linked to the bacterial trans-zeatin synthase (tzs) gene that produces the cytokine trans‑zeatin. This simple Agrobacterium‑mediated approach enables direct comparison of high‑density trichome regions with adjacent isogenic tissue on the same leaf.

The study demonstrates that subfamily I ethylene receptors form the core ethylene‑sensing module and act epistatically over subfamily II receptors, uniquely possessing Ca2+‑permeable channel activity that drives ethylene‑induced cytosolic calcium influx. This reveals a mechanistic link whereby subfamily I receptors integrate hormone perception with calcium signaling in plants.

Infiltration of Nicotiana benthamiana leaves with Agrobacterium tumefaciens strain GV3101 carrying the pMP90 Ti plasmid triggers de novo formation of capitate glandular trichomes and elevates acyl‑sugar production, an effect absent with other strains. The responsible factor is the trans‑zeatin synthase (tzs) gene on pMP90, and exogenous application of cytokinins (trans‑zeatin or benzylaminopurine) alone can reproduce trichome induction, linking cytokinin signaling to trichome development. The study highlights that Agrobacterium-mediated transient assays can have unintended developmental and biochemical impacts, recommending strain testing to mitigate such effects.

The study systematically examines sources of variability in Agrobacterium tumefaciens-mediated transient expression in Nicotiana benthamiana, analyzing a large dataset of 1,915 plants collected over three years. It demonstrates that normalization methods must be validated for each experimental context and provides a statistical model and power analysis framework to determine appropriate sample sizes for detecting specific effect sizes, offering practical guidelines to improve reproducibility in quantitative plant and synthetic biology studies.

The study shows that inoculation with the non‑diazotrophic bacterium Enterobacter sp. SA187 significantly improves Arabidopsis thaliana growth under low nitrate conditions by increasing fresh weight, primary root length, and lateral root density, while enhancing nitrate accumulation and reducing shoot C:N ratios. Transcriptomic and mutant analyses reveal that these benefits depend on ethylene signaling and the activity of high‑affinity nitrate transporters NRT2.5 and NRT2.6, indicating an ethylene‑mediated, HATS‑dependent reprogramming of nitrogen uptake.

The study reveals that Arabidopsis ethylene receptors ETR1 and ERS1 function as Ca²⁺-permeable channels, with ETR1 specifically mediating ethylene‑induced cytosolic Ca²⁺ spikes that influence hypocotyl elongation. Homologous receptors from diverse land plants and algae also show Ca²⁺ permeability, and ethylene further enhances this activity, indicating a conserved regulatory role across the green lineage.

The study demonstrates that ethylene signaling contributes to host resistance against the root parasitic plant Phelipanche aegyptiaca, as both water stress and parasitism activate ethylene responses in Arabidopsis roots. Application of the ethylene precursor ACC reduced parasite attachment, and mutants in ethylene signaling components (ETR1, CTR1) showed altered tolerance, highlighting ethylene-mediated defenses as a potential strategy for crop protection.

Using CRISPR‑Cas9, researchers knocked down CCD7 or CCD8 in Nicotiana benthamiana to suppress strigolactone synthesis, producing compact plants with a 45%–50% smaller spatial footprint while preserving recombinant protein yields (GFP and rituximab). The mutants showed altered leaf proteome, auxin/cytokinin balance, and metabolic fluxes without affecting overall growth rate, demonstrating suitability for indoor vertical farming biopharma production.

The authors created two Nicotiana benthamiana lines with CRISPR-mediated knockouts of two polyphenol oxidase genes, which exhibited slightly accelerated growth and retained normal transient GFP expression. These ppo-deficient plants produced leaf extracts that remained greener with markedly reduced enzymatic browning and protein crosslinking, leading to a nearly fourfold increase in yield and improved purity of a transiently expressed His‑tagged tomato protease. The study demonstrates that PPO depletion can enhance recombinant protein recovery from plant tissue.