PtWOX2 and PtWOX14 accelerate somatic embryogenesis initiation in Pinus massoniana via synergistic hormonal and transcriptional reconfiguration

The PtARF6/PtARF8-PtGH3.1 transcriptional module regulates auxin homeostasis and dwarfism in citrus.

An integrated multi-omics analysis of dwarf and normal-height red tangerine × trifoliate orange hybrid seedlings revealed a PtARF6/8-PtGH3.1 transcriptional module that regulates auxin homeostasis through IAA conjugation, providing genetic insights into GH3.1-mediated dwarfism.

Contrasting Embryogenic Trajectories Reveal Spatial Control as a Key Determinant of Embryogenic Competence in Theobroma cacao L.

ABSTRACT Somatic embryogenesis (SE) in Theobroma cacao is a micropropagation technique of great importance but remains constrained by genotype recalcitrance. The cellular and molecular mechanisms distinguishing regenerative from non‐regenerative responses remain poorly understood. Here, we elucidate the ontogenetic events governing embryogenic competence by comparing responsive genotypes (CCN‐51 and 752) with a recalcitrant one (PH16). Our results demonstrate that SE success in cacao is not determined by cell proliferation speed, but rather by a slow, organized, and spatially confined developmental trajectory. Through histological and immunofluorescence analyses, we show that responsive genotypes establish a focused response within procambial tissues. This leads to the formation of late, localized auxin maxima (after 42 days), which are essential for organizing morphogenesis. In contrast, the recalcitrant genotype exhibits a rapid, diffuse, and disorganized response that fails to establish necessary hormonal gradients, resulting in developmental collapse. We conclude that embryogenic competence in cacao should be redefined: it is not merely an induction event, but the precise orchestration of a developmental program dependent on the controlled reactivation of a vascular stem cell niche. These findings provide novel morphological and hormonal markers for selecting elite genotypes and offer new strategies to overcome recalcitrance in cacao.

Somatic Embryogenesis-Based Tetraploid Induction Enhances Biomass and Freezing Tolerance in Liriodendron Hybrid.

Polyploidization is a key mechanism driving plant evolution, environmental adaptation, and trait improvement. This study investigated the effects of artificial chromosome doubling on growth and freezing tolerance in a Liriodendron hybrid (T × T genotype). Tetraploids were efficiently induced during the liquid suspension stage of somatic embryogenesis using oryzalin, with a maximum induction rate of 33.33%. Compared with diploids, 3-month-old tetraploids exhibited compact growth, characterized by increased stem diameter and markedly enlarged leaf area. Tetraploids also showed larger but less dense stomata, enlarged leaf cells, and denser chloroplast organization. Under freezing stress, tetraploids displayed enhanced tolerance accompanied by coordinated transcriptional reprogramming. Transcriptome analysis revealed significant enrichment of defense-related pathways, including plant hormone signaling (JA, SA, and auxin) and MAPK signaling, together with ploidy-specific calmodulin expression, suggesting Ca2+-mediated regulation of hormone responses. Tetraploids preferentially upregulated genes involved in phenylpropanoid metabolism and lignin biosynthesis, promoting structural defense and redox homeostasis, whereas diploids showed stronger induction of flavonoid biosynthesis genes associated with rapid antioxidant protection. These transcriptional patterns were supported by physiological measurements, with tetraploids accumulating higher lignin content and enzyme activities, while diploids accumulated more flavonoids. Overall, tetraploids and diploids adopt distinct freezing adaptation strategies. Polyploidization drives coordinated regulation of hormone signaling and secondary metabolism, enabling improved biomass allocation and freezing tolerance. This study establishes an efficient tetraploid induction system for Liriodendron hybrid and provides mechanistic insights into polyploid-enhanced stress adaptation in woody plants.

Endogenous rGRF4-GIF1 enables high-efficiency transformation and systemic trichome induction without pleiotropic defects in strawberry.

Genetic improvement of the strawberry is constrained by low regeneration efficiency and pronounced genotype-dependency. While the combination of microRNA396 and Growth-Regulating Factor (GRF)-GRF-Interacting Factor (GIF) chimeras have emerged as potent morphogenic triggers, previous use of heterologous regulators in diploid strawberry reported severe developmental abnormalities. Here, we developed an endogenous, miR396-resistant morphogenic toolkit (FverGRF4-GIF1) that achieves high-efficiency, genotype-independent transformation across both diploid and octoploid strawberry backgrounds without compromising vegetative vigor. Beyond its role in organogenesis, we show that the rGRF4-GIF1 module acts as a master regulator of epidermal cell fate. Constitutive expression of the endogenous chimera induced a systemic development of dense unicellular trichomes on leaves, sepals, and stolon tissues. Integrative transcriptomic and transient Dual-LUC reporter assays revealed that this developmental shift is driven by an epigenetic relay; rGRF4-GIF1 transactivates the histone acetyltransferase GCN5, which in turn promotes trichome initiation through the indirect activation of GL1. Concurrently, the trichome branching program is actively prevented by a GCN5-facilitated induction of the R3-MYB repressor CPC, bypassing canonical GIS-dependent signaling. Physiologically, this epidermal change shifted the leaf surface to a highly hydrophobic state (increased contact angle) and significantly reduced non-stomatal water loss in young tissues by increasing boundary layer resistance. Our findings establish the miR396-GRF-GIF axis as a central coordinator of strawberry morphogenesis and physical desiccation barriers, offering a robust strategy for enhancing environmental resilience in complex polyploid crops.

Spatiotemporal Profiling of the Marchantia Sporophyte Reveals Ancestral Meristem Module and Dynamic Epigenetic Reprogramming during Early Embryogenesis

Molecular ontogeny of Bemisia tabaci life stages reveals miRNA-governed development and egg-stalk support for early embryogenesis.

BACKGROUND Deciphering how developmental gene-regulatory programs interface with lineage-specific reproductive novelties in Bemisia tabaci demands a temporally resolved, integrative molecular framework. Using deep miRNA sequencing, high-throughput transcriptomics, quantitative proteomics, two-dimensional proteo-mapping, and spatially multiplexed FISH, we delineate the circuitry governing whitefly ontogeny. RESULTS This atlas uncovers a previously unrecognized morphological innovation: a transporter-enriched egg stalk operating as an active, metabolically competent nutrient-harvesting appendage. Integrated temporal profiling indicates that the strongest molecular reprogramming in B. tabaci occurs at hatching and adult emergence, consistent with conserved developmental transition points described in other insects. Conserved miRNAs (Btab-mir-34 and Btab-mir-2944b) were associated with early developmental transitions, whereas clade-restricted miRNAs (Btab-mir-307a, Btab-mir-352a, and Btab-mir-107a) were predicted to regulate metabolic, detoxification, and chemosensory networks. Spatial FISH supports that Btab-novel-mir-018a represses vitellogenin during late-nymphal stages, establishing a developmentally gated post-transcriptional module relieved at adult emergence. Comparison of egg versus isolated stalk tissue proteomics revealed a transporter-enriched molecular signature for the B. tabaci egg stalk, extending earlier physiological evidence for pedicel-mediated water and solute uptake. Localization of NaPi-III and RNAi-associated egg viability phenotypes further supports a transport-related role for this structure during embryogenesis. CONCLUSION Collectively, this study provides a stage-wise molecular reconfiguration framework toward understanding the developmental and evolutionary architecture of B. tabaci. Furthermore, preliminary evidence for egg-stalk-associated transport identifies a candidate ontogeny-specific process that may inform future precision pest-management strategies.