The study investigates how the timing of the vegetative phase change (VPC) in Arabidopsis thaliana influences drought adaptation, revealing strong genotype-by-environment interactions that create stage-specific fitness tradeoffs. Genotypes from warmer, drier Iberian climates transition earlier, and genome-wide association mapping identifies loci linked to VPC timing and drought response, with several candidates validated using T‑DNA insertion lines.
The study examined how Arabidopsis calcium‑dependent protein kinases AtCPK5 and AtCPK6 modulate immunity triggered by bacterial rhamnolipids, finding that RLs up‑regulate these kinases and that mutants, especially cpk5/6, show altered reactive oxygen species production and defense gene expression. However, these kinases did not influence RL‑induced electrolyte leakage or resistance to Pseudomonas syringae pv. tomato DC3000, indicating additional signaling components are involved.
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.
Phosphoproteomics uncovers rapid and specific transition from plant two-component system signaling to Ser/Thr phosphorylation by the intracellular redox sensor AHK5
Authors: Drechsler, T., Li, Z., Schulze, W. X., Harter, K. J. W.
A comparative phosphoproteomics study using Arabidopsis thaliana ahk5 loss‑of‑function mutants and wild‑type seedlings revealed that the histidine kinase AHK5 mediates a rapid shift from multistep phosphorelay signaling to serine/threonine phosphorylation in response to H2O2. AHK5 controls ROS‑responsive phosphorylation of plasma‑membrane nanodomain proteins and orchestrates distinct ABA‑independent stomatal closure and ABA‑dependent root development pathways by modulating key components such as RBOHD, CAS, HPCA1, and auxin transporters.
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 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 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.
The study developed a high-throughput phenotyping platform to assess root infestation by Orobanche cumana in a diverse sunflower association mapping population and applied a dual GWAS using SNPs and k-mers to uncover resistance loci. It validated known QTLs with higher resolution, identified novel candidate genes such as leucine‑rich repeat receptor kinases, and highlighted introgressed segments from wild Helianthus species that contribute to broomrape resistance.
Evolutionary origin and functional mechanism of Lhcx in the diatom photoprotection
Authors: Kumazawa, M., Akimoto, S., Takabayashi, A., Imaizumi, K., Tsuji, S., Hasegawa, H., Sakurai, A., Imamura, S., Ishikawa, N., Inoue-Kashino, N., Kashino, Y., Ifuku, K.
Molecular phylogenetic analysis indicated that diatom Lhcx proteins share a common ancestor with green algal Lhcsrs, suggesting acquisition via horizontal gene transfer. Knockout of the Lhcx1 gene in the diatom Chaetoceros gracilis almost eliminated non‑photochemical quenching and revealed that Lhcx1 mediates quenching in detached antenna complexes, while also influencing PSII quantum yield and carbon fixation under high‑light conditions. These findings elucidate the evolutionary origin and mechanistic role of Lhcx‑mediated photoprotection in diatoms.
The study demonstrates that calcium-dependent protein kinases NbCDPK4 and NbCDPK5 directly phosphorylate the NADPH oxidase NbRBOHB at Ser‑123, enhancing sustained ROS production during effector-triggered immunity in Nicotiana benthamiana. Constitutively active CDPKs also upregulate NbRBOHB transcription, and phosphorylation of Ser‑123 is amplified by Ca2+ influx triggered by an autoactive helper NLR (NRC4). These results define a NbCDPK‑NbRBOHB signaling module that links NLR activation to prolonged ROS bursts in ETI.