Genetius

The study characterizes a conserved RNA structural element called DEAD in DEAD-box helicase genes of land plants, showing it acts as a sensor that modulates alternative splicing of DRH1 and its paralog in Arabidopsis thaliana. By opening the structure, splicing shifts toward non‑coding isoforms, creating a negative feedback loop that balances helicase transcript and protein levels, while its disruption leads to widespread splicing defects and severe stress phenotypes.

The study reveals that transcription factors GLK1/GLK2 and ABI4 antagonistically regulate protochlorophyllide accumulation during seedling etiolation, where loss of ABI4 or GLK2 overexpression leads to excess Pchlide, inefficient photoreduction, elevated singlet oxygen, and reduced seedling survival upon light exposure. ABI4 suppresses GLK activity via physical interaction rather than transcriptional control, preventing photodamage in dark-grown seedlings.

The study demonstrates that the plasmodesmata‑located protein PDLP5 negatively regulates plasma membrane intrinsic protein (PIP)‑mediated hydrogen peroxide transport in Arabidopsis by forming extracellular complexes with PIPs, notably PIP2;5. Overexpression of PDLP5 reduces H2O2 uptake and mitigates H2O2‑induced root growth inhibition, while loss‑of‑function mutants show increased sensitivity, revealing a novel extracellular mechanism of aquaporin regulation.

The study characterized cabbage stem flea beetle (CSFB) larval development and assessed antibiosis across a diverse Brassica panel, finding no larval resistance within Brassica napus but consistent antibiosis in Sinapis alba. It also demonstrated that Brassica rapa and Arabidopsis thaliana can serve as suitable hosts for CSFB, enabling future genetic studies of resistance. The results suggest using Brassica relatives to explore CSFB resistance genetics for breeding oilseed rape.

The study enhances virus-induced genome editing (VIGE) by introducing a multiplexed guide RNA system and an engineered high‑activity Ymu1 variant (Ymu1‑WFR) delivered via Tobacco Rattle Virus, enabling efficient, transgene‑free, and heritable multiplex editing. This approach builds on prior transgene‑free VIGE in Arabidopsis using ISYmu1 TnpB and expands its utility for single‑locus and multiplex genome modifications.

The study identifies a cysteine‑rich peptide, FEM, secreted by Arabidopsis thaliana stylar tissues that blocks heterospecific pollen tube elongation, functioning independently of the known barrier component SPRI1. A neighboring pollen‑expressed protein, HOM, interacts with FEM to neutralize its effect, forming a toxin‑antidote system that contributes to multilayered prezygotic reproductive isolation.

The study shows that invasion of the host root xylem by the parasitic plant Phtheirospermum japonicum induces a phosphate‑starvation response in Arabidopsis thaliana, leading to systemic suppression of immunity. Consequently, infested plants become more susceptible to secondary microbial infections, highlighting the importance of multitrophic interactions in crop resilience.

Live-cell imaging of Arabidopsis thaliana pollen tubes co-expressing fluorescent tubulin and actin markers revealed partial co‑localization of the two cytoskeletal systems and demonstrated that microtubule organization depends on actin in a spatially specific manner. Disruption of actin, but not microtubules, perturbs medial microtubules, while EB1b tracking shows a largely parallel microtubule array with plus ends oriented away from the tube apex.

The authors created combinatorial mutants of group II GH3s, DAO1/DAO2, and key UGTs to dissect indole‑3‑acetic acid (IAA) inactivation pathways, using ^13C6‑IAA feeding to trace metabolic flux. Their results show that DAO enzymes act downstream of GH3s and that UGT‑mediated IAA glycosylation plays a larger role in regulating IAA levels and development than previously recognized, while residual GH3 activity and unidentified pathways may contribute to phenotypes such as early flowering via FLC down‑regulation.

Using quantitative live‑cell imaging in Arabidopsis thaliana zygotes, the authors show that plastids migrate apically in two stages: initially together with the nucleus along F‑actin, then via microtubule‑driven movement after nuclear migration slows, resulting in unequal plastid inheritance. Plastid migration is independent of starch but requires a fertilization‑activated MAP kinase pathway, revealing a spatiotemporal regulatory mechanism at the onset of plant development.