Search Results (1,857)

The transition to flowering in Arabidopsis thaliana is governed by complex transcriptional regulatory networks, in which promoter-associated cis-regulatory elements integrate both developmental and environmental cues. To investigate these regulatory interactions, we analyzed promoter motifs of 18 flowering-related genes using curated motif resources, including the Eukaryotic Promoter Database (EPD) and JASPAR, applying stringent statistical thresholds. Transcription factors (TFs), which were predicted to bind across all examined promoters, were designated as putative master regulators, resulting in the identification of 36 candidates, predominantly belonging to the MADS-box, DOF, and IDD families. Positional analyses revealed both proximal and distal binding sites, including a notable motif at −1024 in PISTILLATA and at +466 in SEPALLATA3, potentially indicative of autoregulatory control. Comparative analysis further identified 96 gene-specific associations, reflecting a balance between shared and specialized regulatory mechanisms. Treatment with β-aminobutyric acid (BABA), which has a flowering delaying effect, repressed SQUAMOSA and increased DOF-type TFs, indicating a chromatin-associated reprogramming process, which may coordinate the transcriptional suppression of flowering activators. These findings refine current models of floral regulatory networks and provide testable hypotheses regarding autoregulatory and cross-regulatory circuits in the control of flower development. Full article

Heading date, also known as flowering time, plays a crucial role in determining the regional adaptability of rice (Oryza sativa L.). Heading date is regulated by numerous genes involved in various photoperiod pathways. Here, we isolated the Delayed Heading Date 6 (DHD6) gene from a whole-genome-sequenced rice mutant population. We demonstrated that a 2 bp deletion in the coding region of DHD6 truncates the protein and confers early flowering. Genetic analysis shows that DHD6 functions upstream of Ehd1 and is synergistic with Se14 and PHYC to regulate flowering time. In addition, we identified natural alleles of DHD6 that are associated with heading date and likely contribute to the geographic adaptation of rice. In summary, DHD6 functions upstream of Ehd1, reducing the transcriptional level of Ehd1, thereby delaying flowering. Full article

Brassica juncea is an important leafy vegetable, and flowering time is a key determinant of its yield and quality. In this study, one significantly up-regulated gene, BjuAGL9-2, was identified from RNA-Seq data. qRT-PCR analysis confirmed that BjuAGL9-2 expression was significantly elevated in reproductive organs and reproductive stages. Further five BjuAGL9-2 over-expression (OE) lines were subsequently generated, which showed an early-flowering and pale-yellow leaf phenotype compared to the wild type. qRT-PCR assays found that the mRNA of core floral integrator genes was changed in Arabidopsis OE lines. Yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays indicated that BjuAGL9-2 interacted with BjuTUA5, BjuZFP7, BjuGSTU5, and BjuMAPK16 in vivo. Sub-cellular localization assays showed that BjuAGL9-2 localizes in the nucleus, whereas its interacting partners localize in the cytoplasm. qRT-PCR assays further revealed that BjuTUA5 and BjuGSTU5 were up-regulated in flower buds, while BjuZFP7 and BjuMAPK16 were down-regulated. During vegetative stages, all four genes were up-regulated in B. juncea. As for BjuAGL9-2 interaction protein-encoding homolog genes, except AtGSTU5, the other three genes were up-regulated in Arabidopsis OE lines. Additionally, qRT-PCR analysis of chlorophyll biosynthesis-related genes showed that 19 of 27 genes were up-regulated, while 8 genes were down-regulated, in Arabidopsis OE lines. Collectively, these findings suggest that BjuAGL9-2 promotes flowering and contributes to the pale-yellow phenotype by regulating its interacting protein-coding genes, floral integrators, and chlorophyll biosynthesis genes. Full article

To clarify how nitrogen (N) and water regulate the microbe mediated carbon (C) cycle in farmland, a 3-year experiment was conducted in a wheat–maize rotation at Jiaozhou Station, North China. Twelve treatments combined four drip irrigation regimes (T1: no irrigation; T2: 40 mm irrigation at flowering; T3: 40 mm irrigation at the grain filling stage; T4: both, 40 mm each) and three N levels (N0: 0 kgN·hm⁻²; N1: 92 kgN·hm⁻²; N2: 184 kgN·hm⁻²). In this study, we measured wheat yield and biomass, soil organic carbon and nitrogen content, soil respiration, soil microbial community, and C-metabolic genes. The results showed that wheat yield increased with N, peaking at 8949.81 kg·hm⁻² in the N2T3 treatment, while irrigation had no significant independent effect on yield but interacted with nitrogen fertilization: under identical nitrogen levels (N1, N2), yields in the T1 and T2 treatments were significantly lower than those in the T3/T4 treatments. The soil organic carbon content in N2 was significantly higher; the soil C/N ratio was highest in N2, and T3 resulted in a significantly higher C/N ratio than T1 under the same N level; total soil respiration in N0 was significant lower, and T4 had higher respiration than T2 under the same N level. N addition increased Actinobacteriota, Chloroflexi, Thaumarchaeota, and Ascomycota, while decreaing Proteobacteria and Acidobacteriota. No reduction in fungal phylum was observed with nitrogen addition. N application significantly upregulated key enzymes in the pentose phosphate pathway (e.g., transketolase K00615, transaldolase K00616), while irrigation increased phosphoserine aminotransferase (K00831) abundance and decreased methylmalonyl-CoA mutase (K01848) abundance. N2T3 maintains high SOC content while achieving maximum yield, promoting soil fertility retention. Compared to T4, N2T3 also enhances water use efficiency. The N2T3 treatment (high N and grain filling stage irrigation) achieved the optimal balance between high wheat yield and SOC sequestration. Full article

4-Chlorophenoxyacetic acid (4-CPA) is an auxin-type plant growth regulator widely used in fruit and vegetable production. However, its influence on the nutritional and sensory qualities of horticultural crops remains insufficiently characterized. This study investigated the influence of 4-CPA application and oscillator-mediated pollination on the metabolic composition of fully ripe fruits of Solanum lycopersicum var. cerasiforme cv. ‘Zheyingfen No. 1’. Two concentrations of 4-CPA (16 mg/L and 8 mg/L) were applied during flowering, and their effects on amino acids, soluble sugars, organic acids, and volatile compounds (VOCs) were comparatively analyzed. The results indicated that treatment with 8 mg/L 4-CPA treatment significantly increased the total amino acid content in ripe fruits compared with the control and the 16 mg/L treatment. Among the 17 amino acids identified, the contents of umami-related amino acids, including glutamic acid (Glu) and aspartic acid (Asp), were markedly enhanced. In particular, Glu content in the C8 treatment was the highest and accounted for more than 50% of the total amino acid content. The accumulation of sugars was not significantly affected by 4-CPA treatment, while the C8 treatment resulted in the lowest level of total organic acids, which are crucial for flavor development at the ripening stage. A 29.35% increase in VOCs was observed” for conciseness in 4-CPA-treated fruits compared with the control. Analysis of relative odor activity values (rOAVs) showed that although 4-CPA treatment reduced the number of aroma-active compounds, it promoted the accumulation of β-ionone, thereby shifting the tomato fruit aroma profile toward floral, woody, sweet, and fruity notes. In summary, 4-CPA treatment regulated the nutritional and flavor quality of ripe cherry tomato fruits by increasing the content of Glu and other amino acids, enhancing the diversity of VOCs, and promoting the formation of key aroma-active substances such as β-ionone. Full article

Phalaenopsis orchids are globally significant high-value ornamental flowers due to their strange flower shape, gorgeous color, and long flowering period. The successful implementation of reflowering technology is expected to double the economic value of the Phalaenopsis industry. This study selected the cultivated variety Phalaenopsis ‘Hatuyuki’ as the material to investigate the effects of exogenous gibberellin A₃ (GA₃) application (0, 50, 100, 150, and 200 mg/L) on its reflowering. Growth phenotype analysis indicates that exogenous GA₃ significantly promotes the occurrence of reflowering in Phalaenopsis ‘Hatuyuki’ after the first flowering, specifically manifested in elongated leaves, flower bud differentiation, flower stalk growth, and an earlier onset of flowering. The application of exogenous GA₃ significantly enhances the accumulation of starch, soluble sugars, and proteins in Phalaenopsis ‘Hatuyuki’, while inhibiting the synthesis of free fatty acids. Gibberellins (GA₃, gibberellin A₁ (GA₁), and gibberellin A₈ (GA₈)), cytokinins (6-Benzyladenosine (BAPR) and Kinetin (K)), and indole-3-acetic acids (IAAs) (tryptamine (TRA), indole-3-acetic acid (IAA)) are the core endogenous hormones responding to exogenous GA₃ spraying treatment. Transcriptome analysis identified a total of 3891 differentially expressed genes (DEGs). The KEGG enrichment analysis revealed that the most significantly enriched KEGG pathways included ‘Plant hormone signal transduction’. Key genes involved in the plant hormone signal transduction pathway (AUX, IAA, SAUR, DELLA, MYC2) were validated through qRT-PCR, suggesting that these genes may be crucial for the exogenous GA₃ application that promotes the reflowering of Phalaenopsis ‘Hatuyuki’. Additionally, this study highlights 202 core DEGs responsive to exogenous GA₃. Combined with the analysis of hormone signaling pathways, it provides a new perspective for uncovering the key molecular modules involved in GA₃-regulated reflowering of Phalaenopsis ‘Hatuyuki’. Overall, the findings of this study indicate that exogenous GA₃ application can promote the re-flowering of Phalaenopsis ‘Hatuyuki’. Full article

As an emerging field of life science, epigenetics plays a pivotal role in regulating gene expression. Epigenetic modifications including histone modifications, DNA methylation, chromatin remodeling, non-coding RNAs, and RNA modifications (particularly m⁶A methylation) play crucial roles in fine-tuning plant developmental processes. Among these, floral transition marks a key developmental switch from vegetative to reproductive growth, orchestrated by complex interactions between endogenous signals (such as age and hormones) and environmental cues (such as photoperiod and temperature). Recent advances have uncovered that epigenetic mechanisms act as molecular bridges integrating these signals to ensure flowering occurs under optimal conditions. This review synthesizes the current understanding of epigenetic control in the six canonical flowering pathways—photoperiod, vernalization, autonomous, thermosensory, gibberellin, and age-dependent pathways—with a particular emphasis on the emerging role of m⁶A RNA modification. We also discuss the crosstalk among epigenetic layers and highlight the translational potential of epigenetic engineering in optimizing flowering time and crop adaptation. Full article

Pecan is an important oilseed tree species valued for its nutrient-rich nuts. WRKY and VQ proteins play crucial roles in plant growth, development, and stress response. However, few WRKY and VQ genes in pecan have been functionally analyzed due to functional redundancy caused by gene duplication. In this study, 89 CiWRKYs and 47 CiVQs were identified in pecan genome, which were unevenly distributed across chromosomes. Gene structure and conserved motif analyses revealed high diversity among members. Duplication analysis indicated that segmental duplication was the major factor of family expansion of CiWRKY and CiVQ. Ka/Ks ratios revealed that most duplicated gene pairs underwent purifying selection. Promoter analysis identified numerous cis-acting elements associated with light response, hormone regulation, and abiotic stress, implying their potential regulatory roles in development and stress response. Expression data across six tissues demonstrated tissue-specific patterns, with several genes highly expressed in flowers and roots. Transcriptome analysis revealed that 63 CiWRKY and 27 CiVQ genes were significantly upregulated under drought stress. qRT-PCR validation confirmed that CiPaw.10G165200 and CiPaw.04G072500 were highly induced by salt treatment, with expression levels increasing over 100-fold at 8 d. Moreover, CiPaw.10G165200 was also highly expressed under ABA treatment, which indicated it might play a key role in the response to abiotic stresses. Our results provide valuable insights into the evolutionary patterns and functional roles of WRKY and VQ genes in pecan and lay a foundation for improving stress tolerance and molecular breeding in this economically important nut tree. Full article

In protected horticulture, precise regulation of light intensity [i.e., photosynthetic photon flux density (PPFD)], ambient temperature, and ambient CO₂ concentration is crucial for optimizing crop photosynthesis. Tomatoes, a key greenhouse crop, exhibit temporal variations in photosynthetic efficiency across their growth cycle. However, the differences in the dynamic responses of net photosynthetic rate (Pn) of tomatoes to environmental factors during flowering and fruit development stages in winter solar greenhouses, as well as how to utilize these differences respectively to achieve more precise on-demand environmental regulation, still require in-depth exploration. Based on measured data, this study employed decision tree (DT), random forest (RF), and XGBoost (XGB) models to predict net photosynthetic rate (Pn) across two growth periods. The results demonstrated that, in comparison with the early flowering stage, the photosynthetic potential of tomato leaves increased during the fruit development stage, with the Pn peak increasing by 11.5%. The proportion of observed data points in the high Pn range (25–35 μmol m⁻² s⁻¹) at the fruit development stage was 14.2%, which was significantly higher than the 6.7% observed at the early flowering stage. Meanwhile, the sensitivity of tomato leaves to changes in environmental factors also increased during the fruit development stage. On the independent test set, the XGB model exhibited the best predictive performance: the root mean square error (RMSE) for the early flowering stage model was 0.47 μmol m⁻² s⁻¹, with a mean absolute error (MAE) of 0.36 μmol m⁻² s⁻¹; for the fruit development stage, the RMSE was 0.60 μmol m⁻² s⁻¹, and the MAE was 0.41 μmol m⁻² s⁻¹. This study demonstrated the variation patterns of photosynthetic characteristics of tomatoes at different growth stages in response to environment factors. The established XGB model and the generated three-dimensional visualized Pn prediction surfaces provide a quantitative basis and decision-support tools to facilitate precise environmental management strategies for the coordinated dynamic regulation of light, temperature, and CO₂ in solar greenhouses. Full article

The large-scale cultivation of medicinal plants generates substantial agricultural by-products that are often discarded. A notable example is the floral biomass of Bupleurum chinense DC. (B. chinense), which is routinely removed during cultivation to promote root yield. To explore the potential valorization of these discarded tissues, we performed an integrated transcriptomic and metabolomic analysis of flavonoid biosynthesis across three developmental stages: F1 (Initial Flowering Stage), F2 (Full Bloom Stage), and F3 (Late Flowering Stage). Our results revealed distinct stage-specific regulatory dynamics. Flavonoid biosynthesis was initiated at F1 through the activation of upstream structural genes, reached its peak at F2 with strong up-regulation of branch-specific genes and the accumulation of diverse flavonols and anthocyanins, and declined at F3, despite the sustained presence of several antioxidant metabolites. These findings indicate that F2 represents the optimal stage for harvesting B. chinense flowers to obtain a broad spectrum of bioactive flavonoids, while late-stage flowers may serve as a complementary source of stable antioxidant compounds. Collectively, this study highlights the potential for transforming discarded floral biomass into valuable phytochemical resources and provides a framework for exploring underutilized tissues in other medicinal plants. Full article

Sweet cherry (Prunus avium L.) cultivation is rapidly expanding in Northern Italy, where excessive vegetative vigor often limits fruit set and quality. This study aimed to evaluate the effects of Prohexadione-calcium (Pro-Ca) on the vegetative growth, productivity, and fruit quality of cv. ‘Tip Top’ sweet cherries grafted onto Gisela 6 and MaxMa 14 rootstocks. The growth regulator was applied twice between the flower bud and petal fall stages. Pro-Ca significantly reduced vigor and increased the fruit setting by 10%, resulting in an yield average of +3 kg per plant. Also preharvest treatment increased average cherry size compared with the control, particularly in plants grafted onto Gisela 6. Moreover, Pro-Ca-treated fruits exhibited a +20% red overcolor extension of the skin, improved skin firmness (+12%), and led to higher nutraceutical properties. In conclusion, Pro-Ca improved plant yield and fruit quality in ‘Tip Top’ sweet cherry, likely through the combined effects on hormonal balance, assimilate allocation, and canopy light distribution, supporting its potential as a valuable growth regulator in high-density sweet cherry orchards. Full article

Bougainvillea spp. is a well-known ornamental plant that is widely applied in urban landscaping construction. The colorful bracts of Bougainvillea in full bloom become important for urban landscape during special festivals. Although flowering regulation measures of Bougainvillea attracted much attention, the underlying mechanism of flower bud differentiation and development remains poorly understood. Here, we induced flowering of Bougainvillea glabra ‘Sao Paulo’ under 6-BA treatment and conducted RNA sequencing data analysis to characterize the molecular regulatory mechanism of flower development in response to 6-BA. Transcriptome analysis indicated that a series of genes and transcription factors of cytokinin metabolism, flowering and floral development regulation, and photoperiod regulation were upregulated by the 6-BA treatment, including COL, AP2, FT, SOC1, LFY, SPL4, SPL9, and SPL13. Moreover, the expression of these important genes exhibited relatively high levels of thorns compared to apical buds, suggesting that flower bud differentiation probably starts with the thorns in Bougainvillea. This study confirms that 6-BA treatment at certain concentrations can promote flowering of Bougainvillea and provides insight into the regulatory mechanism of the growth regulator acting on early flowering of Bougainvillea. Full article

[Background] Marigold (Tagetes erecta L.) is the main source of the natural pigment lutein. [Methods] In this study, Marigold served as the experimental material for systematic observation of floral organ development. Based on floral morphology and lutein content, the full-flowering stage was identified as the optimal harvesting period. [Results] Under different light intensity gradients (30–1500 μmol·m⁻²·s⁻¹), the highest lutein content in petals occurred at ≈500 μmol·m⁻²·s⁻¹. Increased light intensities promoted flowering and enlarged flower diameter while significantly shortening the growth cycle. Transcriptome analysis revealed that light intensity variation markedly influenced the expression of genes related to metabolic pathways, plant hormone signal transduction, and carotenoid biosynthesis, and enriched transcription factor families including bHLH, MYB, NAC, and WRKY. Metabolomic profiling identified lutein esters, such as lutein dimyristate and lutein dipalmitate, as the dominant accumulated forms, with their contents positively correlated with light intensity; under high light, intermediate metabolites, including α-cryptoxanthin and zeaxanthin, were significantly up-regulated. [Conclusions] This study clarifies the molecular mechanism by which light intensity precisely regulates lutein accumulation through coordinated synthesis, esterification, and degradation pathways, offering a theoretical foundation for light-regulated cultivation of T. erecta L. and efficient lutein production. Full article

Color serves as a crucial visual signal for attracting pollinating insects and directly affects the fruit set rate in woody crops. This study investigated the molecular mechanisms underlying flower color formation in macadamia. The results demonstrated that darker flower colors were associated with higher fruit set rates: the rates for purple, pink, pinkish-white, and white flowers were 2.78, 1.99, 1.35, and 1.31, respectively. High-throughput sequencing identified 1359 differentially accumulated metabolites, including benzoic acid, 4-hydroxybenzaldehyde, and isorhamnetin. Transcriptional regulators such as ERF, MYB, and WRKY were significantly up-regulated in darker flowers. KEGG analysis revealed two key metabolic pathways, in which genes including HCT (shikimate hydroxycinnamoyl transferase) and F3GalTase (flavonol 3-O-galactosyltransferase), as well as related metabolites such as p-coumaric acid, chlorogenic acid, and myricetin, showed higher expression levels in darker flowers. Anthocyanin content was highest in pink and pinkish-purple varieties (462.79 and 446.35 μg/g, respectively), and lower in white and light pink varieties (140.52 and 167.97 μg/g). In conclusion, flower color intensity is positively correlated with both fruit set rate and anthocyanin content. Genes involved in the flavonoid and phenylpropanoid pathways, along with transcription factors such as WRKY and MYB, collectively regulate flower color formation. This study provides a theoretical basis for macadamia flower color breeding. Full article

Background/Objectives: miR5200 is miRNA unique to Poaceae plants. Induced under short-day conditions, it modulates flowering time by regulating the florigen FT gene expression. However, to date, the genetic locus responsible for mature miR5200 formation remains experimentally unvalidated, and its biological function in abiotic stress responses remains unknown. This has hindered systematic elucidation of miR5200’s physiological role and molecular mechanisms. Methods: This study utilized wheat as the research material. First, through bioinformatics analysis at the genomic level, 13 potential candidate tae-miR5200 gene loci were screened. Subsequently, the authenticity of these gene loci was systematically validated by combining tobacco transient transfection-based GUS staining assay and quantitative real-time PCR (qRT-PCR) to detect expression levels. Building upon this foundation, the expression patterns of tae-miR5200 under abiotic stresses such as low temperature, drought, and salinity, as well as SA, ABA, IAA, GA₃, and MeJA treatments, were further investigated. Results: Experimental validation confirmed that 7 out of 13 potential gene loci are authentic and functional, and tae-miR5200 exhibited specific expression changes under different types of abiotic stress. Conclusions: This study confirms the authenticity of tae-miR5200 gene loci, effectively eliminating interference from bioinformatics-predicted false-positive loci in subsequent functional studies. It provides an experimental foundation for further investigation into the molecular mechanisms of tae-miR5200 in wheat responses to abiotic stress. Full article