Thidiazuron-induced growth and developmental changes reshape metabolic, photosynthetic and transcriptomic signatures in Arabidopsis thaliana seedlings.

Dynamic transcriptomic and metabolomic responses to seed germination in Luffa cylindrica.

Seed dormancy is a critical agronomic trait that affects uniform germination and seedling establishment in Luffa cylindrica. In this study, we performed phenotypic, transcriptomic, and metabolomic analyses on two contrasting Luffa cylindrica materials: Z-184 and Z-114. Phenotypic evaluation revealed that compared with Z-114 seeds, Z-184 seeds exhibited significantly lower germination potentials and germination rates. Transcriptomic analysis revealed that the DEGs were predominantly associated with plant hormone signal transduction, MAPK signaling, and metabolic pathways. Metabolomic profiling revealed 2,469 metabolites, with 728 showing significant changes during dormancy release. Integrated transcriptomic and metabolomic analyses highlighted coordinated changes in hormone-, energy-, and secondary metabolism-related pathways. Hormone quantification further demonstrated that the differential accumulation of GA₄, trans-zeatin and trans-zeatin riboside (tZ + tZR), and 2- cis-4-trans- (+) abscisic acid (an isomer of abscisic acid, ABA) was closely associated with the contrasting dormancy phenotypes. These findings provide reference data for the study of the dormancy mechanism of seeds in Luffa cylindrica and lay the foundation for the breeding of weakly dormant Luffa cylindrica.

Involvement of ascorbate oxidase in the regulation of the leaf development mediated by mepiquat chloride in cotton seedlings

Mepiquat chloride (MC), a plant growth regulator, is extensively used in agricultural practices. However, the mechanism of action of MC is complex and remains largely unclear. In this study, the effects of MC on the leaf development of cotton seedlings and the underlying regulatory mechanism were investigated by integrating morphological, physiological, transcriptomic analysis and virus-induced gene silencing technology. The results showed that MC treatment caused a reduction in leaf area and an increase in chlorophyll content and photosynthetic efficiency. The ascorbic acid content initially increased and then declined after MC treatment. Transcriptomic data demonstrated that the expression of the ascorbate oxidase (AO) gene was initially upregulated and subsequently downregulated by MC. The top 20 KEGG pathways identified from the differentially expressed genes were mainly enriched in plant–pathogen interaction, the MAPK signaling pathway, ascorbate and aldarate metabolism, plant hormone signal transduction, amino acid metabolism, and secondary metabolism. Silencing GhAO1 enhanced the ascorbic acid concentration, which was accompanied by increased plant height, internode length, and leaf area in cotton seedlings. Silencing GhAO1 reduced the sensitivity of cotton seedlings to MC. This study reveals that MC may primarily serve as an abiotic stressor that regulates the stress response during the early stage of MC treatment and may further enhance chlorophyll content by promoting amino acid and secondary metabolism. AO plays an important role in MC-mediated growth regulation in cotton seedlings.

Transcriptomic and predictive modeling reveal photosynthetic and stress responses associated with ALAD silencing in citrus

The multifaceted role of gibberellins in somatic embryogenesis: from in vitro culture to molecular networks

Gibberellins (GAs) are central regulators of plant growth and development, yet their involvement in somatic embryogenesis (SE) has received limited attention and often produces contradictory results. This review critically examines the current knowledge on the role of GAs in SE by integrating evidence from physiological, molecular, and developmental studies across a wide range of plant species. Available data indicate that exogenous GAs and GA biosynthesis inhibitors can either promote or inhibit the induction, progression, and conversion of somatic embryos, depending on the species, genotype, explant origin, developmental stage, and culture conditions. These opposing effects underscore that exogenous responses are tightly linked to endogenous GA homeostasis. Particular attention is paid to GA metabolism and signaling genes, whose expression patterns during SE reveal substantial interspecific and genotypic variation. Endogenous GA profiles reveal that both high and low levels of bioactive GAs correlate with SE induction across different systems, suggesting that endogenous GA levels may be a key determinant of embryogenic competence and may underlie major differences in regeneration capacity among species and genotypes. Furthermore, GAs function within a broader regulatory network through extensive crosstalk with other hormones (auxins, abscisic acid, cytokinins, and ethylene), environmental factors (e.g., light and temperature) and interactions with major embryogenesis-related transcription factors such as LEC1, LEC2, FUS3, ABI3, AGL15, AGL18, and BBM. These interactions position GAs as dynamic components of a multilayered hormonal and transcriptional framework that controls the switch from somatic to embryogenic development. Integrative approaches—including hormone profiling, gene expression analysis, functional genetics, and developmental studies—are essential to elucidate the precise function of GAs in SE and thereby improve protocols for plant regeneration.

Gibberellin Homeostasis Perturbation Alters Sugar Metabolism and Developmental Traits in Agapanthus praecox subsp. orientalis

Gibberellins (GAs) are essential hormones that regulate plant growth and development, yet the downstream metabolic pathways through which they modulate phenotypic plasticity remain poorly understood. Here, we investigated the GA-mediated regulatory network in Agapanthus praecox subsp. orientalis by integrating phenotypic, transcriptomic, and targeted metabolomic analyses across three complementary perturbation strategies: gradient paclobutrazol (PAC) treatments, GA20ox RNA interference (RNAi) lines, and exogenous GA4 rescue. PAC suppressed vegetative growth dose-dependently and completely arrested floral development at 200 mg·L−1, while increasing soluble sugar and starch contents; plants treated with it in the first year displayed enhanced vegetative growth in the following season, suggesting a possible carbon legacy effect. GA20ox silencing caused dwarfism and flowering failure, which were largely rescued by GA4. Exogenous GA4 restored bioactive GA pools to above wild-type levels without recovering endogenous synthesis, indicating functional compensation. Transcriptomic and qRT-PCR analyses revealed that sugar metabolism-related genes and metabolites underwent the most pronounced changes among all tested categories; these changes were partially reversed by GA4, though certain catabolic genes remained suppressed, revealing hierarchical regulatory logic. Collectively, these findings indicate that GA is closely associated with growth and carbohydrate allocation, and that the GA–sugar metabolic axis represents a major downstream component in developmental plasticity. This study provides species-specific insights into GA-mediated growth regulation and offers implications for ornamental crop management.

dizzy1 coordinates shoot and root development, constitutive stress responses, and phytohormone signaling in maize

We identified the monogenic recessive maize (Zea mays L.) mutant dizzy1 in a segregating F2-family by a forward genetic screen of the BonnMu population, a sequence-indexed collection of Mutator transposon-induced mutants. dizzy1 exhibits a dwarf phenotype with pronounced twisting of leaves and roots. Histological analyses revealed irregular cell organization in dizzy1, including enlarged upper epidermal cells in leaves and disorganized cortical cell architecture in roots. Physiological analysis of primary roots indicated reduced cell viability, reflected by increased membrane permeability and altered metabolic activity. Hormone response assays further showed that dizzy1 is insensitive to brassinolide, exhibits a delayed auxin-promoted shoot response, and displays altered gibberellin effects on lateral root development. Bulked segregant RNA sequencing mapped the dizzy1 locus to chromosome 2. Comparative transcriptome profiling of primary roots identified 4,378 differentially expressed genes between wild type and dizzy1, revealing widespread transcriptional reprogramming. Consistent with functional enrichment analyses, histochemical and spectrophotometric assays indicated elevated reactive oxygen species and increased lignin in diz1 primary roots. These findings define dizzy1 as a pleiotropic developmental mutant linking hormone signaling, redox homeostasis, and cell wall regulation in maize growth.