Search Results (455)

This study aimed to develop seed-based mass propagation techniques for the conservation and horticultural and medicinal uses of Scrophularia koraiensis Nakai, an endemic plant in the Korean Peninsula. Seeds were collected from four different locations (accessions) and subjected to untreated (control), gibberellic acid (GA)-only treatment, cold stratification-only treatment, or a cold stratification + GA treatment. Except for seeds collected from one location, the control group exhibited low germination of below 20% in all other locations. However, the GA-only and cold stratification-only treatments released seed dormancy and promoted germination compared with the control. In particular, the cold stratification-only treatment at 5 °C for 4 weeks resulted in about 80% germination in all accessions and demonstrated positive effects on germination speed and uniformity. These findings indicated that S. koraiensis seeds exhibit non-deep physiological dormancy (PD). Upon comparing the seed dormancy classes across various species of Scrophularia, native to different continents and countries, we confirmed that PD is very well conserved in the genus Scrophularia. Therefore, the study outcomes will provide fundamental and practical insights into the seed dormancy and germination characteristics of various Scrophularia species for future studies. Full article

Tyrosine (Tyr) degradation is a crucial pathway in animals. However, its role in plants remains to be examined. Fumarylacetoacetate hydrolase (FAH) is the final enzyme involved in Tyr degradation. Studies of a mutant of the SHORT-DAY SENSITIVE CELL DEATH 1 (SSCD1) gene encoding FAH in Arabidopsis have shown that blockage of this pathway results in the accumulation of Tyr metabolites, thereby inducing cell death under short-day conditions. Seed dormancy is a critical trait which is regulated by endogenous and environmental cues, among which abscisic acid (ABA) and gibberellin (GA) are the primary effectors. ABA induces seed dormancy, whereas GA releases seed dormancy. In this study, sscd1 seeds displayed deep dormancy and hypersensitivity to the GA biosynthesis inhibitor paclobutrazol, but not to ABA during germination. However, exogenous GA₃ could not completely recover dormancy or germination of sscd1 seeds. Moreover, GA₃ level was reduced, which was consistent with the decreased expression of GA3-oxidase 1 in imbibed sscd1 seeds. Furthermore, SSCD1 acted upstream of RGA-LIKE 2. Eliminating the accumulation of Tyr metabolites by inhibiting homogentisate dioxygenase, an enzyme upstream of FAH, completely rescued the phenotype of sscd1 seeds. Additionally, germination of sscd1 seeds was hypersensitive to FAH deficiency-induced accumulation of succinylacetone, which is a Tyr metabolite. These findings suggest that FAH deficiency in sscd1 causes accumulation of Tyr metabolites, thereby disrupting GA biosynthesis and signaling. This resulted in deep dormancy and hypersensitivity to paclobutrazol during germination and highlights the important role of the Tyr degradation pathway in GA-mediated seed dormancy and germination. Full article

The Neotropical Savanna (Cerrado) is a fire-prone biome characterized by seasonal climate, nutrient-poor soils, and variable fire regimes. While fire-induced germination responses are well documented in Cerrado plants, the role of seed size in mediating thermal tolerance remains poorly understood. Here, we investigate how seed size and fire-related heat treatments influence germination in Hymenaea stigonocarpa, a keystone Cerrado tree species. Specifically, we test the predictions that (i) low to moderate fire temperatures (<270 °C) do not impair seed germination and (ii) larger seeds exhibit greater heat tolerance than smaller seeds. We exposed 360 seeds from 30 individual trees to five heat-shock treatments (27, 100, 150, 200, and 270 °C) simulating fire intensities typically experienced in the Cerrado. Our results show that H. stigonocarpa produces relatively large seeds with an average germination rate of approximately 42%. The average time required for germination was 12.18 ± 0.43 (average ± standard error) days. The time required for seed germination varied significantly as a function of heat-shock treatment and seed mass, with seeds exposed to the highest temperature (270 °C) taking longer to germinate. Moreover, seed mass had a positive effect on the time required for seed germination. The germination percentage remains stable across heat treatments and seed sizes, indicating that H. stigonocarpa seeds exhibit characteristics typical of heat-tolerant species rather than those of heat-stimulated species. Our study showed that H. stigonocarpa trees produce large seeds that germinate quickly and are tolerant to moderate temperatures. These seed traits play a crucial role in the reproductive success of individual plants in fire-prone, nutrient-poor, and water-limited ecosystems. Furthermore, our results offer important guidance by emphasizing the role of seed size in effective restoration initiatives. Full article

Trials were carried out to investigate the effects of light and temperature on C. rotundus seeds and tubers under two conditions: (i) in vitro and (ii) after sowing in soil. In the latter, seedling emergence was evaluated after sowing at increasing depths in different soil textures. While dormancy was evident in over 50% of the seeds, which also required light for germination, in contrast, tubers showed a significantly shorter period of dormancy that was independent of light. Seed burial strongly hindered seedling emergence, showing an “active” seed bank only in the shallowest soil layer (few mm). In contrast, tubers showed a marked ability to emerge from a depth exceeding 40 cm. Emergence capacity was found to be proportional to the size of the tubers, attributable to the greater energy reserves needed during autotrophic pre-emergence growth. Seedling emergence from both seeds and tubers, sown at increasing depths, was inhibited to a greater extent in a clay soil texture. A lower inhibitory effect was reported for sandy soils. Tuber vitality was significantly reduced or eliminated within a few days from progressive drying following exposure to solar rays during summer periods. Finally, the data were discussed within the context of planning the agronomic management of C. rotundus, in terms of soil tillage modalities, to ensure sustainable control of this strongly invasive and persistent weed. Full article

Seed dormancy is a key ecological attribute influencing germination timing and the ability of species to establish in variable environments. This study investigated whether inter-population variability in seed dormancy expression exists in Lonicera etrusca, a Mediterranean shrub known for producing seeds with underdeveloped embryos and multiple dormancy types. Seeds were collected from four geographically and ecologically distinct populations in central Iberia and subjected to a series of germination experiments simulating natural seasonal temperature regimes, stratification treatments, and gibberellic acid application. Across all populations, seeds exhibited morphological dormancy (MD) and varying degrees of morphophysiological dormancy (MPD), including non-deep simple and deep complex types. Despite high intra-specific variability in dormancy expression, no significant differences were found among populations for germination patterns or embryo growth responses. This indicates that dormancy variability is an intrinsic, conserved feature of the species rather than a locally adaptive trait. The homogenization of germination strategies across populations may be facilitated by bird-mediated seed dispersal, promoting gene flow and limiting local selection. These findings support the hypothesis that dormancy polymorphism in L. etrusca reflects a flexible germination strategy that enhances colonization potential across heterogeneous Mediterranean environments, rather than an environmentally induced plastic response. Full article

Seed-related traits such as seed size, germination, vigour, dormancy, biochemical composition, and stress resistance are critical to ensuring agricultural productivity and global food security, particularly in current scenarios of climate change and environmental unpredictability. This review examines the transformative potential of omics technologies, encompassing genomics, transcriptomics, proteomics, metabolomics, epigenomics, and phenomics, in enhancing our understanding of seed biology and its applications in crop improvement. Genomics and transcriptomics are key technologies in future plant breeding and gene editing to optimise seed yield and quality. We reviewed the role of metabolomic approaches in uncovering the molecular mechanisms behind seed germination, vigour, dormancy, and the proteomic advances to elucidate markers of seed quality, combining these omic technologies to decipher DOG1 as a marker of dormancy. Both biotic and abiotic stress resistance in seeds were reviewed from a multi-omics perspective to determine the best avenues for improving the resilience of seeds against drought, salinity and pathogens. Moreover, omics approaches have been reviewed to optimise plant–microbe interactions, particularly in enhancing symbiotic relationships within the soil microbiome. Full article

To explore the potential of plasma technology in regulating seed germination, this study compared the effects of direct treatment with needle-plate electrodes using DC and pulse power supplies, and indirect treatment with plasma-activated water on the growth characteristics of Bromus inermis seeds. By comparing different pulse power parameters, including voltage, pulse width, frequency, and duration, it was found that treatments at 15 kV, 2500 ns, 6 kHz, and 10 min significantly increased the surface hydrophilicity and germination performance of the seeds. The best conditions for DC power supply were 15 kV and 10 min. Indirect treatment with plasma-activated water (15 kV, 10 min) effectively broke the seed dormancy by regulating active nitrogen oxygen particle components, increasing the germination percentage by 50%. Analysis of antioxidant enzyme activity showed that in seedlings the activities of superoxide dismutase (SOD) and peroxidase (POD) increased by 75% and 21%, respectively, after treatment, revealing the mechanism of oxidative stress response induced by plasma. This study provides theoretical and technical references for the application of plasma technology in enhancing seed vitality and agricultural practices. Full article

Weedy rice (Oryza spp.) has become one of the most harmful weeds in rice fields worldwide. It is a conspecific plant of cultivated rice (Oryza sativa L.) belonging to the genus Oryza, widely occurring in global rice production systems with a cosmopolitan distribution across major rice-growing regions. Due to its unique biological characteristics, such as strong environmental adaptability, stress resistance, seed shattering propensity, seed dormancy, and competitive dominance, weedy rice can rapidly proliferate and persist in fields, posing a severe threat to rice production systems. This review summarizes the current research progress on the biological characteristics of weedy rice and introduces the significant differences in biological characteristics between weedy and cultivated rice, such as phenotypic diversity, seed shattering, dormancy, strong competitiveness, stress resistance, and early maturity. These distinct biological traits, which significantly differ from cultivated rice, serve as essential mechanisms in the survival strategy of weedy rice. Our review will provide a theoretical reference for a deeper understanding of weedy rice and its integrated management. Full article

Within the context of sustainable exploitation of phytogenetic resources, the present study aimed to develop species-specific seed germination protocols for eighteen native and potentially underutilized plant species originating from northeastern Greece. The taxa were selected based on their antioxidant potential and their provenance to enhance their regional exploitation potential, thus utilizing the species’ local adaptation traits. To quantify the maximum germination potential in each case, seed viability was assessed using the tetrazolium (TTZ) test. The pre-treatments applied for seed dormancy release included cold stratification and the application of gibberellic acid (GA₃) and kinetin. Germination tests revealed that 9 of the 18 species exhibited high germination percentages in the control treatment (ranging between 64 and 90%) indicating that after-ripening was sufficient for any seed dormancy release in a significant portion of the seed lot. Furthermore, cold stratification and hormonal treatments significantly enhanced germination in seven species (final seed germination up to 85%), indicating deeper physiological dormancy and confirming the role of cold stratification and phytohormones in dormancy release. Two species showed no germination under any pre-treatment while viable, indicating the presence of more complex dormancy mechanisms. Germination percentages were frequently lower than the corresponding seed viability values, which ranged from 70% to 100%, suggesting that a portion of the seed lot exhibited deeper dormancy throughout. The results showcased species with favorable germination patterns, thus successfully identifying species that can be readily propagated, as well as species that require specific pre-treatments. The study sets the basis for domestication and sustainable use of local antioxidant-rich flora, providing a clear roadmap for the agronomic utilization of the focal species to support the regional bioeconomy. Full article

Basic helix-loop-helix (bHLH) transcription factors represent one of the largest transcriptional regulator families in cereal crops such as rice, maize, and wheat. They play crucial and diverse roles in regulating key agronomic traits and essential physiological processes. This review provides a systematic synthesis of the functionally characterized bHLH genes across the three major cereals, offering a comparative perspective on their roles in growth, development, and stress responses. We comprehensively summarize their documented functions, highlighting specific regulators such as TaPGS1 for grain size, rice ILI subfamily for leaf angle, OsbHLH004 for seed dormancy and maize “Ms23-Ms32-bHLH122-bHLH51” cascade for the anther development. Their conserved and species-specific functions in iron homeostasis (e.g., IRO2) and in responses to drought, cold, salinity, and pathogens are also detailed. Additionally, we discuss the underlying molecular mechanisms, including specific binding to E-box/G-box cis-elements, protein dimerization, and integration with hormone signaling pathways. By integrating the current knowledge, this review serves as a consolidated and up-to-date reference that highlights the strategic potential of bHLH transcription factors in molecular breeding programs for improving yield, quality, and stress tolerance in cereals. Full article

Seed dormancy and germination is regulated by internal hormones and exogenous environment cues. Ethylene is one of the hormones that break seed dormancy and induce seed germination. Our previous study showed that N-degron pathway gene, proteolysis6 (PRT6) was involved in dormancy release by ethylene, the defection of which exhibiting ethylene-insensitivity in Arabidopsis thaliana. In the present study, through screening an ethyl methyl sulfonate-mutagenized (EMS) population of prt6−1, we isolated a recessive mutant that acted as a suppressor of prt6 that rescued its insensitivity to ethylene as well as a phenotype of shorter silique length. Further bulk segregant analysis on F2 population identified a premature termination located in the third exon of LONGIFOLIA1 (LNG1), previously reported in the regulation of longitudinal cell elongation. Mutation of LNG1 in prt6−1 background by CRISPR-Cas9 confirmed that LNG1 was epistatic to PRT6 in seed responsiveness to ethylene. Our finding proposed the pleiotropic effect of LNG1 in seed dormancy breakage by ethylene via PRT6, providing novel functional component at the downstream of the coordinated PRT6 and ethylene signaling pathway. Full article

There is an urgent and constant need for land reclamation and to restore self-sustaining, stable, and resilient ecosystems. It is necessary to enhance the frequency, consistency, and success rates of applying native plant seed for ecological restoration. Smoke-water can affect seed germination of plants, regardless of whether they occur in fire-prone ecosystems. Germination trials of 18 native species of Indigenous value in the southern interior grasslands of British Columbia, Canada were conducted using a smoke aqueous solution. Locally sourced parent plant material was burned to produce smoke-water. Seeds were collected from multiple populations of the species across a wide geographic range within the B.C. southern interior to increase the genetic diversity of the seed stock. Seeds were soaked in smoke aqueous solution in various concentrates, including 0% (control), 1% (1:100), 10% (1:10), 20% (1:5), and 100%. The results indicate that germination rates in the presence of smoke-water are species-specific. Five species showed an increase in germination with smoke-water (Erythronium grandiflorum, Calochortus macrocarpus, Arnica latifolia, Lomatium nudicaule, and Shepherdia canadensis); four species showed no change (Rosa woodsii, Crataegus douglasii, Lewisia rediviva, and Prunus virginiana); and nine species showed some level of decrease (Fritillaria affinis, Fritillaria pudica, Berberis aquifolium, Claytonia lanceolata, Gaillardia aristate, Balsamorhiza sagittata, Allium cernuum, Amelanchier alnifolia, and Lomatium macrocarpum). Smoke-water also affected germination rate by plant form (herbs > shrubs), plant phenology (spring ephemeral and protracted > summer quiescent and summer mature) and plant dispersal mechanism (wind > animal). The treatments applied to encourage the germination of seeds from interior grassland forbs and shrubs have demonstrated that smoke-water can effectively break dormancy and enhance the germination rate from certain native plant species. Full article

The Passifloraceae family is one of the most representative in tropical America, with food, pharmaceutical, and ornamental importance. This study evaluated seed morphometry and germination of eight accessions of four Passiflora edible species, P. edulis; P. ligularis; P. quadrangularis; and P. tripartita var. mollissima, by studying accessions conserved several years in the gene bank (−15 °C) and recently collected accessions. Four experimental phases were carried out as follows: (1) morphometric characterization of seeds with qualitative and quantitative variables; (2) evaluation of germination under two thermal regimes (20 °C/30 °C and 25 °C); (3) application of six pre-germination treatments to overcome dormancy; and (4) tetrazolium tests. In phase 1, P. quadrangularis stood out for its unique morphological characteristics according to multivariate analysis. In phase 2, the alternating thermal regime (20 °C/30 °C) promoted the highest germination. In phase 3, the germination response was specific to each species: mechanical scarification in P. edulis (85.7%), KNO₃ (0.5%) in P. ligularis (35.7%), control in P. quadrangularis (71.1%), and gibberellic acid (GA₃ 400 ppm) in P. tripartita (71.4%). The tetrazolium phase 4 identified the viability status of the seeds. It is concluded that the differences in morphometry and germination reflect the intrinsic characteristics of each species, highlighting the importance of specific protocols for their germination. This study provides tools to optimize the conservation and regeneration of Passiflora spp. germplasm under ex situ conditions, as a genetic base to be utilized in the future. Full article

Kiwifruit (Actinidia Lindl.) cultivation is restricted to climates similar to its native habitat in China. The seeds, a product of sexual reproduction, are used to produce rootstocks in commercial plantations, being an important source of genetic diversity for adaptation to variable conditions and emerging challenges. It is known that obtaining kiwifruit plants from seeds is difficult due to their characteristic dormancy. However, the effect of habitat and parents on seed characteristics and their relationship to the seedlings produced is unknown. Here, we show that plants with tolerance to extreme conditions provide advantages to their offspring. We point out that Actinidia arguta cv. Passion Poppers (kiwiberry), capable of tolerating extreme temperatures below zero, has a larger seed size (volume over 15 mm³) and weight (100 seeds weigh nearly 200 mg), greater germination capacity (90.75 ± 1.03), and more robust seedlings (quotient of 20.28 ± 0.75) than classic green and golden kiwifruits, and one tropicalized commercial kiwifruit from Veracruz, Mexico. These findings highlight that parental origin influences seed quality and seedling establishment. We noted that A. arguta seeds offer opportunities for mass plant propagation. In addition, the use of parental plants adapted to extreme conditions could be an effective strategy to improve seed and seedling quality, with factors such as long-term survival and development in new environments awaiting to be explored in extent. Full article

Long noncoding RNAs (lncRNAs) have emerged as key regulators of gene expression during seed development and physiology. This review examines the diverse roles of lncRNAs in key stages of seed development, including embryogenesis, maturation, dormancy, germination, and aging. It integrates the current understanding of the biogenesis and classification of lncRNAs, emphasizing their functional mechanisms in seeds, particularly those acting in cis and trans. These mechanisms include the scaffolding of polycomb and SWI/SNF chromatin remodeling complexes, the guidance of RNA-directed DNA methylation, the ability to function as molecular decoys, and the modulation of small RNA pathways via competitive endogenous RNA activity. This review highlights the regulatory influence of lncRNAs on abscisic acid (ABA) and gibberellin (GA) signaling pathways, as well as light-responsive circuits that control dormancy and embryonic root formation. Endosperm imprinting processes that link parental origin to seed size and storage are also discussed. Emerging evidence for epitranscriptomic modifications, such as m6A methylation, and the formation of LncRNA–RNA-binding protein condensates that maintain resting states and coordinate reserve biosynthesis are also reviewed. Advances in methodologies, including single-cell and spatial transcriptomics, nascent transcription, direct RNA sequencing, and RNA–chromatin interaction mapping, are expanding the comprehensive lncRNA landscape during seed development and germination. These advances facilitate functional annotation. Finally, possible translational research applications are explored, with a focus on developing lncRNA-based biomarkers for seed vigor and longevity. Full article