Genetius

The study identifies the cysteine‑rich receptor‑like kinase CRK5 as a negative regulator of salicylic‑acid‑mediated cell death and a positive regulator of antioxidant homeostasis during dark‑induced leaf senescence in Arabidopsis. Loss‑of‑function crk5 mutants display accelerated senescence, elevated ROS and electrolyte leakage, and altered antioxidant enzyme activities, phenotypes that are rescued by suppressing SA biosynthesis or catabolism. Transcriptome analysis reveals extensive deregulation of senescence‑ and redox‑related genes, highlighting CRK5’s central role in coordinating hormonal and oxidative pathways.

The study characterizes the chloroplast‑localized protein AT4G33780 in Arabidopsis thaliana using CRISPR/Cas9 knockout and overexpression lines, revealing tissue‑specific expression and context‑dependent effects on seed germination, seedling growth, vegetative development, and root responses to nickel stress. Integrated transcriptomic (RNA‑seq) and untargeted metabolomic analyses show extensive transcriptional reprogramming—especially of cell‑wall genes—and altered central energy metabolism, indicating AT4G33780 coordinates metabolic state with developmental regulation rather than controlling single pathways.

The study examined the roles of AtKUP2, AtKUP6, AtKUP8, and GORK potassium transport proteins in guard cell function by performing gas-exchange measurements on mature Arabidopsis leaves. Loss of KUP2/6/8 reduced stomatal conductance, whereas a GORK loss‑of‑function mutant showed increased conductance, yet the magnitude of light‑ and ABA‑induced transpiration changes remained similar across genotypes, suggesting a limited dynamic range for rapid stomatal movements that relies on small ionic osmolytes.

The study demonstrates that FERONIA and phytochrome B physically interact with the NADPH oxidase RBOHD, and that FERONIA-mediated phosphorylation of phyB is essential for RBOHD-driven ROS production under excess light stress in Arabidopsis thaliana. Additional membrane proteins CRK10 and PIP2;6 also associate with this complex, forming a plasma‑membrane assembly that integrates multiple signaling pathways to regulate stress‑induced ROS.

The study shows that Arabidopsis root tips adapt to hypoxia by increasing H3K4me3 levels, linked to the inhibition of group 7 demethylases (KDM7s). Genetic loss of KDM7s mimics hypoxic conditions, activating genes that sustain meristem survival, suggesting KDM7s act as root‑specific oxygen sensors that prime epigenetic tolerance mechanisms.

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.

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.

The study demonstrates that the chromatin remodeler DDM1 is essential for biomass heterosis in Arabidopsis thaliana hybrids, as loss of DDM1 function leads to reduced rosette growth and extensive genotype‑specific transcriptomic and DNA methylation changes. Whole‑genome bisulfite sequencing revealed widespread hypomethylation in ddm1 mutants, while salicylic acid levels were found unrelated to heterosis, indicating that epigenetic divergence, rather than SA signaling, underpins hybrid vigor.

The study reveals that the methyl‑CpG‑binding domain protein MBD8 interacts with the histone demethylase LDL2 to facilitate removal of H3K4me1 and transcriptional repression downstream of H3K9me2 in Arabidopsis. MBD8 binds GC‑poor DNA independently of cytosine methylation and stabilizes LDL2 protein levels, indicating a broader role for MBD proteins beyond methyl‑DNA recognition.

The study applied a progressive, sublethal drought treatment to Arabidopsis thaliana, collecting time‑resolved phenotypic and transcriptomic data. Machine‑learning analysis revealed distinct drought stages driven by multiple overlapping transcriptional programs that intersect with plant aging, and identified high‑explanatory‑power transcripts as biomarkers rather than causal agents.