The study identifies the AP2/ERF transcription factor GEMMIFER (MpGMFR) as essential for asexual reproduction in the liverwort Marchantia polymorpha, showing that loss of MpGMFR via genome editing or amiRNA abolishes gemma and gemma cup formation, while dexamethasone‑induced activation triggers their development. Transient strong activation of MpGMFR initiates gemma initial cells at the meristem, which mature into functional gemmae, indicating MpGMFR is both necessary and sufficient for meristem‑derived asexual propagule formation.
The study identified the poplar homolog of Arabidopsis HDG11 and generated transgenic poplar hybrids overexpressing PtaHDG11. Constitutive expression conferred markedly improved drought tolerance, as evidenced by higher leaf water content, reduced oxidative damage, up‑regulation of antioxidant genes, and greater post‑stress biomass, while also causing a glabrous phenotype. These results highlight PtaHDG11 as a promising target for breeding drought‑resilient trees.
The authors performed a genome-wide analysis of 53 CCCH zinc‑finger genes in pearl millet, identified seven stress‑responsive members and demonstrated that overexpressing PgC3H50 in Arabidopsis enhances drought and salt tolerance. They showed that the ABA‑responsive transcription factor PgAREB1 directly binds the PgC3H50 promoter, activating its expression, as confirmed by yeast one‑hybrid, dual‑luciferase and EMSA assays, defining a new PgAREB1‑PgC3H50 regulatory module.
The study examined how DNA methylation influences cold stress priming in Arabidopsis thaliana, revealing that primed plants exhibit distinct gene expression and methylation patterns compared to non-primed plants. DNA methylation mutants, especially met1 lacking CG methylation, showed altered cold memory and misregulation of the CBF gene cluster, indicating that methylation ensures transcriptional precision during stress recall.
A SABATH family enzyme regulates development via the gibberellin-related pathway in the liverwort Marchantia polymorpha
Authors: Kawamura, S., Shimokawa, E., Ito, M., Nakamura, I., Kanazawa, T., Iwano, M., Sun, R., Yoshitake, Y., Yamaoka, S., Yamaguchi, S., Ueda, T., Kato, M., Kohchi, T.
The study identified 12 SABATH methyltransferase genes in the liverwort Marchantia polymorpha and demonstrated that MpSABATH2 is crucial for normal thallus growth and gemma cup formation. Loss‑of‑function mutants displayed developmental phenotypes reminiscent of far‑red light responses, which were linked to gibberellin metabolism and could be partially rescued by inhibiting GA biosynthesis or supplying the GA precursor ent‑kaurenoic acid. These findings suggest that SABATH enzymes independently evolved regulatory roles in land‑plant development.
The study demonstrates that carbon availability promotes gemma cup formation in Marchantia polymorpha by activating cytokinin signaling, which up‑regulates the transcription factors MpGCAM1 and MpSTG. Pharmacological and genetic manipulations showed that cytokinin accumulation in response to sucrose and high light is sufficient to overcome low‑sucrose repression, and that this pathway operates independently of KAI2A‑MAX2 mediated karrikin signaling. The findings suggest a conserved carbon‑cytokinin interaction governing developmental plasticity across land plants.
A comprehensive multi‑environment trial of 437 maize testcross hybrids derived from 38 MLN‑tolerant lines and 29 testers identified additive genetic effects as the primary driver of grain yield, disease resistance, and drought tolerance. Strong general combining ability and specific combining ability patterns were uncovered, with top hybrids delivering up to 5.75 t ha⁻¹ under MLN pressure while maintaining high performance under optimum and drought conditions. The study provides a framework for selecting elite parents and exploiting both additive and non‑additive effects to develop resilient maize hybrids for sub‑Saharan Africa.
The study used paired whole‑genome bisulphite sequencing and RNA‑seq on wheat landraces to investigate how DNA methylation patterns change during drought stress, revealing antagonistic trends across cytosine contexts and a key demethylation role for ROS1a family members. Gene‑body methylation correlated positively with expression but negatively with stress‑responsive changes, while drought‑induced hyper‑methylation of specific transposable elements, especially the RLX_famc9 LTR retrotransposon, appears to modulate downstream gene regulation via siRNA precursors.
The study examined DNA methylation dynamics in Arabidopsis thaliana shoots and roots under heat, phosphate deficiency, and combined stress using whole-genome bisulfite sequencing, small RNA‑seq, and RNA‑seq. Distinct stress‑specific methylation patterns were identified, with heat and combined stress causing CHH hypomethylation, phosphate deficiency causing hyper‑ and hypomethylation in shoots and roots respectively, and the combined stress exhibiting a unique signature independent of additive effects. Methylation changes were concentrated in transposable elements and regulatory regions, implicating RdDM and CMT2 pathways and suggesting a role in chromatin accessibility rather than direct transcriptional control.
The study characterizes the liverwort-specific NPR protein (MpNPR) in Marchantia polymorpha, demonstrating that it controls oil body formation and confers resistance to gastropod herbivory through interaction with the transcription factor MpERF13. Loss- or gain-of-function of MpNPR disrupts MpERF13‑dependent gene expression and compromises defense against snail feeding, revealing a lineage‑specific immune pathway distinct from tracheophyte NPR functions.