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.
KATANIN promotes cell elongation and division to generate proper cell numbers in maize organs
Authors: Martinez, S. E., Lau, K. H., Allsman, L. A., Irahola, C., Habib, C., Diaz, I. Y., Ceballos, I., Panteris, E., Bommert, P., Wright, A. J., Weil, C., Rasmussen, C.
The study identifies two maize genes, Discordia3a and Discordia3b, that encode the microtubule‑severing protein KATANIN. Loss‑of‑function allele combinations reduce microtubule severing, impair cell elongation, delay mitotic entry, and disrupt preprophase band and nuclear positioning, leading to dwarfed, misshapen plants.
Six new Viola species and two reinstated species from China were identified using field surveys, detailed morphological comparison, and phylogenetic analysis of ITS and GPI gene sequences, placing them in section Plagiostigma subsect. Diffusae. The GPI data offered higher resolution, indicating complex relationships possibly due to ancient hybridization or incomplete lineage sorting, thereby clarifying species boundaries and evolutionary patterns in Chinese Viola.
The study uncovers a reciprocal regulatory loop between type one protein phosphatases (TOPPs) and EIN2 in ethylene signaling, showing that ethylene induces TOPPs expression and that TOPPs dephosphorylate EIN2 at S655 to stabilize it and promote nuclear accumulation. TOPPs act upstream of EIN2, while EIN3/EIL1 transcriptionally activates TOPPs, linking dephosphorylation to enhanced ethylene responses and improved salt tolerance.
The study identified lineage-specific long non‑coding RNAs (lncRNAs) from the aphid‑specific Ya gene family in Rhopalosiphum maidis and R. padi, demonstrating that these Ya lncRNAs are secreted into maize, remain stable, and move systemically. RNA interference of Ya genes reduced aphid fecundity, while ectopic expression of Ya lncRNAs in maize enhanced aphid colonization, indicating that Ya lncRNAs act as cross‑kingdom effectors that influence aphid virulence.
The study provides a comprehensive genome-wide catalog and single‑cell expression atlas of the carbonic anhydrase (CA) gene family in maize, identifying 18 CA genes across α, β, and γ subfamilies and detailing their structural and regulatory features. Phylogenetic, synteny, promoter motif, bulk tissue RNA‑seq, and single‑cell RNA‑seq analyses reveal distinct tissue and cell‑type specific expression patterns, highlighting β‑CAs as key players in C4 photosynthesis and γ‑CAs in ion/pH buffering, and propose cell‑type‑specific CA genes as targets for improving stress resilience.
The study used a computer‑vision phenotyping pipeline (EarVision.v2) based on Faster R-CNN to map Ds‑GFP mutant kernels on maize ears and a statistical framework (EarScape) to assess spatial patterns of allele transmission from the apex to the base. They found that alleles causing pollen‑specific transmission defects often show significant spatial biases, whereas Mendelian alleles do not, indicating that reduced pollen fitness can shape the spatial distribution of progeny genotypes in Zea mays.
The study presents a plant‑focused phylogenetic analysis of class B flavin‑dependent monooxygenases, identifying eight distinct families and revealing lineage‑specific diversification, especially in the NADPH‑binding domain. Using known FMOs as baits, they assembled flavin‑related proteins from key Viridiplantae lineages, performed domain architecture and motif analyses, and reclassified several families, providing a framework for future functional studies.