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 identifies the extended NT‑C2 domain of Plastid Movement Impaired 1 (PMI1) as the main membrane‑binding module that interacts with PI4P and PI(4,5)P2, requiring basic residues for plasma‑membrane association. Calcium binding by the NT‑C2 domain modulates its phosphoinositide preference, and cytosolic Ca2+ depletion blocks blue‑light‑induced PMI1 redistribution, indicating that both the NT‑C2 domain and adjacent intrinsically disordered regions are essential for PMI1’s role in chloroplast movement.

The authors used a bottom‑up thermodynamic modelling framework to investigate how plants decode calcium signals, starting from Ca2+ binding to EF‑hand proteins and extending to higher‑order decoding modules. They identified six universal Ca2+-decoding modules that can explain variations in calcium sensitivity among kinases and provide a theoretical basis for interpreting calcium signal amplitude and frequency in plant cells.

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 reveals that rice perceives Xanthomonas oryzae pv. oryzae outer membrane vesicles through a rapid calcium signal that triggers plasma‑membrane nanodomain formation and the re‑organisation of defence‑related proteins, establishing an early immune response. Without this Ca2+ signal, OMVs are not recognized and immunity is weakened.

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.

Using a microfluidic valve rootchip, the study simultaneously tracked ROS and calcium dynamics in compressed roots and found three kinetic phases linking mechanosensitive channel activity, NADPH oxidase‑dependent ROS accumulation, and secondary calcium influx. Pharmacological inhibition revealed that a fast calcium response is mediated by plasma‑membrane mechanosensitive channels, while a slower calcium increase is driven by ROS production.