Search Results (135)

In dormant sunflower achenes, several structures—the pericarp, seed coat and embryo—contribute to the repression of germination. Achene dormancy varies widely among cultivated sunflower genotypes, and understanding its transmission to hybrid progeny is important both for hybrid seed production and for clarifying the role of these structures. This study examined the inheritance of dormancy in the F1 progeny, with particular emphasis on thermo-inhibition (inhibition of germination at warm temperatures). Reciprocal crosses were performed using three oilseed inbred lines with contrasting dormancy phenotypes. Germination of achenes, seeds, and embryos was tested at 10 and 30 °C at harvest and during postharvest, together with hormonal responses (abscisic acid, ethylene and gibberellins) and measurements of endogenous ABA levels. Results show that maternally inherited, pericarp-imposed thermo-inhibition depends on the dormancy level of the hybrid embryo, which follows a zygotic pattern with incomplete dominance. While embryo sensitivity to ABA related positively with thermo-inhibition, surprisingly, embryonic ABA content was inversely related to dormancy level across genotypes. These findings provide new insight into physiological control of achene dormancy in sunflower and contribute to improved breeding strategies for high-quality hybrid seed. Full article

This study proposes a two-stage Hurdle machine-learning framework for Customer Lifetime Value (CLV) prediction under zero-inflated non-contractual retail settings, where conventional single-stage approaches may suffer from prediction instability and retransformation issues when zero and non-zero spending are jointly modeled. Using the UCI Online Retail II dataset, comprising 4026 customers with a 62.5% zero-spending rate, Stage 1 employs XGBoost to estimate purchase occurrence probability, while Stage 2 applies gradient- boosting regressors to predict conditional spending intensity. The inverse hyperbolic sine (arcsinh) transformation handles 59 customers with negative net spending from product returns. The Two-stage CatBoost model achieves a coefficient of determination of 0.522, outperforming the best single-stage mean-squared-error (MSE) model (0.385), the default Tweedie-loss baseline in the main 30-seed comparison (0.309), and the Beta-Geometric/Negative Binomial Distribution (BG/NBD) baseline (0.395). The contribution combines architectural innovation with a comprehensive validation protocol—including 5 × 2 CV paired t-tests, out-of-time validation, and SHAP interpretability—confirming that purchase frequency drives occurrence probability while monetary value dominates spending magnitude. A dual-dimension segmentation based on purchase probability (P) and conditional spending intensity (E) identifies 96 Dormant, High-E customers with only a 26% purchase rate despite high expected spending, demonstrating that high conditional spending does not guarantee purchase occurrence. Full article

Large reservoir construction generates vast drawdown zones characterized by novel hydrological regimes that impose unprecedented selective pressures. While annual plants serve as pioneer colonists during secondary succession in these ecosystems, the mechanisms allowing their seeds to persist through prolonged anti-seasonal flooding remain poorly understood. We investigated how seed germination responses to extreme submergence are influenced by dormancy traits and phylogenetic history. We conducted a field experiment on 44 common annual plant species in the Three Gorges Reservoir drawdown zone. Seeds were subjected to maximum submergence depths of 0 m (control), 5 m, 10 m, 15 m, and 20 m, along the reservoir’s hydrological gradient. Post-submergence germination percentages were measured and analyzed using linear and Bayesian phylogenetic mixed-effects models, with seed dormancy status, seed type, season, and species’ phylogenetic relationships as explanatory variables. Submergence significantly reduced overall seed germination (p < 0.001), but more than 75% of species retained germination capacity even after 20 m of submergence. Germination percentage distributions shifted from near-normal to bimodal with increasing depth. Although the regression of squared PIC values against phylogenetic branch lengths showed a significant relationship, phylogenetic signal for germination percentages was weak and non-significant across all depths (Pagel’s λ < 0.101, Blomberg’s K < 0.228, p > 0.05). Bayesian models revealed that dormancy season significantly interacted with submergence depth (Estimate = −1.41, 95% CrI [−2.16, −0.67]). Seeds dormant during autumn-winter maintained stable germination percentages across depths, while germination of spring-summer dormant seeds declined significantly with increasing depth. Our findings demonstrate that annual plant seeds possess widespread, species-specific tolerance to extreme submergence. This tolerance is primarily driven by environmental filtering rather than phylogenetic history. The seasonality of dormancy is a crucial adaptive mechanism, enabling seeds, particularly those dormant in autumn-winter, to withstand the harsh conditions of the Three Gorges Reservoir drawdown zone. This study provides a functional trait-based framework for selecting suitable species for the ecological restoration of reservoir drawdown zones globally. Full article

Effective weed management is crucial for optimizing agricultural productivity and minimizing environmental impacts. Weeds are most effectively managed during their seedling or early growth stages, which can be achieved with the aid of tools for predicting seedling emergence. However, many persistent weed species exhibit dormant seedbanks, thus complicating prediction attempts. The number of seedlings emerging in these species is closely tied to seedbank dormancy levels, which are influenced by seasonal variations. Thus, predictive population-based threshold models incorporate seedbank dormancy regulation to accurately forecast seedling “window” emergence. These models use the functional relationship between environmental cues (i.e., temperature, light, alternating temperatures, and soil water content) and seed dormancy behavior. Considering that these environmental signals vary among microsites in the field, these tools can be adapted to predict weed emergence in both temporal and spatial dimensions, thus making them suitable for site-specific weed management. The aim of this review is to synthesize existing modeling approaches and present a conceptual framework for dynamic, site-specific weed emergence predictions, supported by case-study-based applications. The illustrative application shows that incorporating soil water content into dormancy dynamics modifies emergence timing and magnitude, restricting emergence to specific topographic zones and potentially reducing herbicide use by up to 60–70%. This approach can improve the efficiency of herbicide applications and other control measures, reducing costs and environmental impact while enhancing crop yields. This work underscores the potential of integrating environmental cues into sophisticated modeling approaches to address the complexities of weed emergence in diverse agricultural landscapes. Full article

The plant-specific TCP transcription factor family plays crucial roles in morphogenesis and stress adaptation. While characterized in many species, this family remains unstudied in Punica granatum. We performed the first genome-wide analysis of the TCP family in pomegranate, identifying 24 PgTCP genes classified into the PCF, CIN, and CYC/TB1 subclades, supported by conserved gene structures and motifs. Evolutionary analysis indicated segmental duplication and purifying selection shaped this family. Expression profiling revealed distinct spatiotemporal patterns: PgTCP2/9/14/21 were highly expressed in flowers, with PgTCP21 also notably abundant in fruit tissues (seed coats and pericarp), suggesting roles in reproductive development. PgTCP19, an ortholog of the branching suppressor BRC1, showed dominant expression in dormant buds, implicating it in shoot architecture regulation. Furthermore, PgTCP5 and the miR319-targeted PgTCP22 were leaf-predominant, indicating a function in leaf development. Under abiotic stress, PgTCPs displayed dynamic, treatment-specific responses. A subset of genes was rapidly induced by cold, while PgTCP14 and PgTCP23 showed sustained upregulation during drought. Several light-responsive PgTCPs were suppressed under shading. This study provides a foundational resource, functionally classifies the PgTCP family, and identifies key candidates regulating organ development and stress resilience for future functional validation and molecular breeding in pomegranate. This work provides the first comprehensive overview of the TCP gene family in pomegranate and offers candidate genes for future functional studies related to development and stress responses. Full article

Viviparity is rarely reported in species with seed physical dormancy. This is because physical dormancy, common in tropical trees, results from the impermeability of the seed tegument to water and regulates the timing of germination. Records of germination within the fruit in such species suggest greater functional plasticity than traditionally assumed. This study reports and quantifies viviparity in Hymenaea martiana seeds over four consecutive years (2019–2022) and assessed seed dormancy status through vigor tests. Sixty fruits were collected annually, and viviparity was estimated as the proportion of fruits containing at least one seed with radicle protrusion. Non-viviparous seeds were subjected to emergence tests with and without mechanical scarification, and cumulative emergence, percentages of dead and water-impermeable seeds, and seed water content were evaluated. Viviparity occurred consistently, affecting approximately 10–15% of the fruits, with no significant differences between years, indicating that the phenomenon was not associated with extreme environmental events. However, early germination did not result in seedling establishment because the emerging roots dehydrated while still inside the fruit. Mechanical scarification significantly increased emergence, confirming the presence of seed physical dormancy. These results show that, although viviparity was observed recurrently in the studied population of H. martiana, seed physical dormancy remains the main mechanism controlling germination in this species. Full article

Background/Objectives: Uveal melanoma (UM) is the most common intraocular malignancy in adults. Although brachytherapy of the primary tumor provides an approximate 80% five-year survival, with time, nearly half of patients experience predominant liver metastases. It was proposed that malignant cells migrate early and stay dormant as they adapt to the liver microenvironment. We propose that cancer vaccine-mediated activation of UM-targeted immunity in primary UM patients could prevent progression of metastatic disease from dormant cells or malignant seeds. Thus, this study explored DNA vaccination as a measure to educate the immune system to recognize the most common UM-associated Q209L tumor driver mutation in GNAQ and GNA11 G-alpha proteins. Methods: Several DNA constructs encoding mutated GNAQ were developed and tested for activation of UM-reactive T cells in HLA-A2/Hd transgenic mice and human T cells ex vivo. Results: Constructs containing immune-enhancing PADRE and VP22-derived epitopes boosted T cell responses against mutant GNAQ, which correlated with reduced experimental lung metastases. Ex vivo dendritic cell-mediated T cell activation with vaccine constructs containing optimized structure produced cytolytic T cells that secreted IFN gamma and killed mutated GNAQ-expressing UM cells in vitro. Conclusions: These findings propose the utility of the fusion DNA vaccines in eliciting T cell immunity against UM cells bearing the Q209L mutation in GNAQ/GNA11 protein to prevent the establishment and progression of metastatic disease. Full article

Low salinity tolerance during germination and early seedling establishment limits large-scale cultivation of halophytes for forage, food, restoration, and conservation purposes. This study evaluates the potential of redox priming to enhance salt tolerance in the perennial C₄ halophyte grass Urochondra setulosa, which could be used as a revegetation and phytoremediation crop for coastal saline lands. Fresh seeds were found to be non-dormant with ~90% mean final germination (MFG) in distilled water. Redox priming, including hydrogen peroxide (H₂O₂), melatonin (MT), sodium nitroprusside (SNP; a nitric oxide donor), and ascorbic acid (AsA), significantly accelerated the germination rate index (GRI) and reduced mean germination time (MGT) without altering MFG under non-saline conditions. Salinity severely suppressed germination, as unprimed seeds reached only ~1% MFG with ~99% germination reduction (GR) and near-zero germination stress tolerance index (GSTI) at 200 mM NaCl. All priming treatments significantly improved MFG, GRI, and GSTI and decreased GR, with H₂O₂ priming showing the highest amelioration. Ungerminated seeds from all treatments recovered ~90% germination capacity in water, indicating enforced dormancy owing to osmotic constraints. Salinity did not impair growth in unprimed seedlings. However, MT priming uniquely enhanced total length, leaf area, and seedling vigor index (SVI) at 200 mM NaCl, while MT and SNP priming resulted in the highest chlorophyll and carotenoid contents. Multivariate analyses confirmed MT’s consistent superiority across traits under stress. Thus, H₂O₂ priming optimizes germination, while MT priming improves seedling vigor and offers a practical, targeted strategy to improve early-stage salinity tolerance in U. setulosa for coastal revegetation and sustainable saline agriculture. Full article

Cnidium monnieri is a valuable functional plant with significant potential for green pest control. However, its large-scale application is limited by its low and uneven seed germination in fields. To determine the factors that affect the germination of C. monnieri seeds, we examined its seed viability, germination percentage and germination speed index (GSI) after seed-coat treatments, water permeability, and the types and activity of endogenous inhibitory substances in C. monnieri seeds. The results indicated that the seed viability of C. monnieri is 95%, but the germination percentage was relatively low (12.60%). Seed coat removal significantly enhanced both the germination percentage and the GSI, but had no significant effect on water absorption rate. Moreover, ethyl acetate extracts completely inhibited the seed germination of the control non-dormant Brassica rapa subsp. rapa, while diethyl ether extracts showed moderate suppression, and petroleum ether extracts exhibited the weakest effect. And the three endogenous inhibitory substances, i.e., dibutyl phthalate, 2,6-di-tert-butylphenol, and 2,4-di-tert-butylphenol significantly reduced the seed germination, seedling height and root length of B. rapa, indicating their high inhibitory efficiency on seed germination. Our study demonstrates that the mechanical barrier of the seed coat and the presence of potent endogenous germination inhibitory substances are the key factors influencing the germination of C. monnieri seeds. These findings provide a theoretical basis for promoting seed germination of C. monnieri, which enhance its application value as functional plant for green pest control. Full article

Sandbur [Cenchrus longispinus (Hack.) Fernald] is a major invasive weed in the agro-pastoral ecotone of northern China. It propagates via seeds encased in spiny burs. Each bur encloses a pair of seeds, and the larger M-type seeds germinate first, functioning as pioneer plants, while smaller P-type seeds remain dormant. Thus, the rapid germination of M-type seeds is pivotal for population sustenance. In this study, we investigated the transcription response involved in the germination of C. longispinusus M-type seeds during four stages (drying, imbibition, exposure, and sprouting). A total of 24,399 DEGs were identified by comparing two consecutive germination stages, with most DEGs found in the imbibition stage. GO enrichment analysis showed that the DEGs were mainly enriched in substance metabolic and regulatory processes. Correspondingly, KEGG enrichment analysis indicated that the functions of DEGs were significantly concentrated in secondary metabolite synthesis pathways, as well as substance and energy metabolic pathways. Notably, the expression of starch-and-sugar metabolism-related genes increased as germination progressed. Additionally, ABA synthesis-related genes were notably downregulated, while those regulating ABA catabolism were significantly upregulated. Moreover, GA synthesis-related genes were activated, especially in the imbibition stage, with nine GA20ox genes highly expressed. These research findings help us gain a deeper understanding of the seed germination mechanism of C. longispinus. Full article

Crop wild relatives (CWRs) are critical resources for crop improvement and addressing food security. The genus Solanum includes many wild species genetically related to major crops. However, seed propagation methods for Solanum taxa distributed on the Korean Peninsula are not well-established. In this study, seed morphology and effects of incubation conditions on germination and dormancy were evaluated in 6 Solanum species classified as CWRs in Korea: Solanum lyratum, S. japonense, S. nigrum, S. sarrachoides, S. americanum, and S. viarum. The seeds possessed fully developed embryos at the time of dispersal and the seed coats readily absorbed water. We investigated germination characteristics under various temperatures, cold stratification periods, and gibberellic acid (GA₃) concentrations. Germination percentage of S. lyratum and S. japonense was significantly higher under cold stratification (≥62.0% after 12 weeks at 5 °C) or GA₃ treatment (≥77.0% at 1000 mg·L⁻¹) than for temperature treatment alone (≤3.0% at 25/15 °C), indicating non-deep physiological dormancy (PD). Seeds of S. nigrum, S. americanum, and S. viarum exhibited non-deep PD with conditional dormancy and higher germination efficiencies through GA₃ 1000 mg·L⁻¹ than under temperature treatment alone (25/15 °C). Seeds of S. sarrachoides were classified as non-dormant. These findings may contribute to the practical mass propagation of Solanum. Full article

Background: Transcription factors (TFs) critically regulate gene expression, orchestrating plant growth, development, and stress responses. The conserved IDD (INDETERMINATE DOMAIN) TF family modulates key developmental processes, including root, stem, and seed morphogenesis. Dendrocalamus latiflorus Munro, an economically vital sympodial bamboo in southern China, suffers significant yield losses due to prevalent bamboo shoot abortion, impacting both edible shoot production and timber output. Despite the documented roles of IDD TFs in shoot apical meristem expression and lateral organ regulation, their genome-wide characterization in D. latiflorus remains unstudied. Methods: Using IDD members from Arabidopsis thaliana, Oryza sativa, and Phyllostachys edulis as references, we identified 45 DlIDD genes in D. latiflorus. Comprehensive bioinformatics analyses included gene characterization, protein physicochemical assessment, phylogenetic reconstruction, and examination of gene structures/conserved domains. Differential expression of DlIDD genes was profiled between dormant and sprouting bamboo shoots to infer putative functions. Results: The 45 DlIDD genes were phylogenetically classified into three subfamilies and unevenly distributed across 34 chromosomes. Whole-genome duplication (WGD) events drove the expansion of this gene family. Promoter analyses revealed enriched cis-regulatory elements associated with hormone response and developmental regulation. Functional analyses suggested potential roles for DlIDD genes in bamboo shoot development. Conclusions: This study provides a foundation for future research to elucidate the functions of IDD TFs and their regulatory mechanisms in bamboo shoot morphogenesis and lateral bud development within woody monocots. Full article

Globally, biodiversity is declining, meaning that many endemic plants are under threat; therefore, it is essential to develop conservation strategies. Scutellaria indica var. coccinea has great potential as an ornamental ground cover plant, but it is a plant that requires ex situ conservation. This study was conducted in order to investigate the seed germination characteristics and classify the dormancy type of S. indica var. coccinea seeds, with the aim of developing mass propagation protocols for ex situ conservation and preservation of their genetic diversity. Fresh and mature seeds of S. indica var. coccinea are in a dormant state, which is released by low temperatures during winter, resulting in radicle and seedling emergence the following spring. At the time of dispersal, the seeds had fully developed embryos, and the seed coat was permeable. When the seeds were incubated under four different temperature regimes (4, 15/6, 20/10, or 25/15 °C), they showed a low germination percentage (≤20%), indicating that a substantial proportion of the seeds remained in a dormant state. In the cold stratification experiment (0, 4, 8, or 12 weeks at 4 °C), germination increased, and the time required for germination shortened as the duration of cold treatment lengthened. This suggests that low temperatures are the primary environmental signal that induces germination. In the gibberellic acid (GA₃) treatment (GA₃ 0, 10, 100, or 1000 mg·L⁻¹), relatively high concentrations (100 and 1000 mg·L⁻¹) were effective in promoting germination. The highest germination was obtained in GA₃ 1000 mg·L⁻¹ with 100.0%, which is about 7 times higher than the control (13.6%). Therefore, seeds of S. indica var. coccinea were classified as having non-deep physiological dormancy (PD). Additionally, because the minimum germinable temperature range of the seeds was extended to lower temperatures, the seeds were classified as having type 2 non-deep PD. Full article

Identifying optimal seed sources is critical for the propagation and restoration of Juglans neotropica Diels in the northern Ecuadorian Andes, where populations are declining due to habitat loss and overexploitation. This study evaluated the seed quality and germination performance of Juglans neotropica from three ecologically distinct provenances: a natural regeneration site (Cuyuja), a pure plantation (Natabuela), and an agroforestry system (Pimampiro). Five phenotypically superior trees were selected from each site, and germination was assessed under controlled nursery conditions over a 150-day period using a completely randomized design. Initial viability tests confirmed the physiological integrity of the seeds across all provenances. Germination onset ranged from day 55 to day 73, with significant differences in germination percentage, speed, and uniformity. The agroforestry provenance showed the highest germination rate (69%) and superior performance in all physiological indices, while natural regeneration had the lowest (15%). Post-trial viability assessments indicated that a substantial proportion of non-germinated seeds from Cuyuja remained dormant or deteriorated. These findings underscore the role of agroforestry systems in enhancing seed physiological quality and support their prioritization for large-scale propagation and ecological restoration initiatives involving Juglans neotropica. Full article

This study investigates the germination ecology of three Lepidium species, including the invasive, indehiscent-fruited Lepidium appelianum and Lepidium draba, and the invasive, dehiscent-fruited Lepidium campestre. The ability of Lepidium species to germinate under a wide range of temperature conditions is significant for understanding their potential invasiveness and establishment in novel and extreme environments. This study aims to clarify the germination behavior of L. appelianum, L. draba, and L. campestre, thereby enhancing our understanding of their invasive potential and ecological implications in the context of a changing climate. The base (Tb), optimum (To), and maximum temperatures for 50% germination (Tc(50)) were determined across a broad thermal gradient following standard protocols. Freshly harvested seeds and fruits of L. appelianum are non-dormant. In contrast, L. draba exhibit pericarp-mediated chemical dormancy, while L. campestre demonstrates physiological dormancy, which is released through after-ripening. The results indicate that L. appelianum and L. draba seeds and fruits germinate at a base temperature (Tb) of 1 °C and 4 °C, respectively. On the other hand, L. campestre seeds germinate at a Tb of 5.8 °C. The optimum temperature (To) for the germination of seeds and fruits in L. appelianum and L. draba ranges from 23 °C to 25 °C, while the To for L. campestre seed germination is 16 °C to 18 °C. Additionally, the maximum temperature for 50% germination (Tc(50)) for L. appelianum fruits is 39.8 °C, for L. draba it is 34.4 °C, and L. campestre reports a (Tc(50)) ranging from 27.4 °C to 33.3 °C for freshly harvested and after-ripened seeds, respectively. These results demonstrated that L. appelianum and L. draba can germinate across a broad temperature range, from very cold to very hot, unlike L. campestre. These findings suggest that the unique reproductive strategy of indehiscent fruits, coupled with a wide thermal germination niche, may contribute to the invasive success of L. appelianum and L. draba. Given the projected climate warming, the results highlight the potential for increased invasiveness of these species and suggest the need for targeted management strategies. Full article