Search Results (44)

Sphagneticola trilobata (L.) Pruski has been introduced into many countries due to its ornamental and economic value. However, it has been listed in the world’s 100 worst alien invasive species due to its invasive nature. This species easily escapes cultivation and forms dense ground cover. It reproduces asexually through ramet formation from stem fragments. It also produces a large number of viable seeds that establish extensive seed banks. The movement of stem fragments and the dispersal of seeds, coupled with human activity, contribute to its short- and long-distance distribution. S. trilobata grows rapidly due to its high nutrient absorption and photosynthetic abilities. It exhibits high genetic and epigenetic variation. It can adapt to different habitats and tolerate various adverse environmental conditions, including cold and high temperatures, low and high light irradiation, low nutrient levels, waterlogging, drought, salinity, and global warming. S. trilobata has powerful defense systems against herbivory and pathogen infection. These systems activate the jasmonic acid signaling pathway, producing several defensive compounds. This species may also acquire more resources through allelopathy, which suppresses the germination and growth of neighboring plants. These life history traits and defensive abilities likely contribute to its invasive nature. This is the first review to focus on the mechanisms of its invasiveness in terms of growth and reproduction, as well as its ability to adapt to different environmental conditions and defend itself. Full article

The promising field of low-temperature plasma treatment, known for its non-invasive and environmentally sustainable nature, is being actively investigated for its ability to enhance germination, emergence, yield, and overall plant development in a broad spectrum of crops. For gene bank requirements, low-temperature plasma technologies can also improve germination parameters and promote the development seeds suitable for long-term storage. Seeds from four selected cultivars of wheat, oats, flax, and rapeseed stored in the gene bank for 1, 10, and 20 years were subjected to plasma treatments for 20, 25, and 30 min. The study evaluated the mean root and shoot length, root–shoot ratio, and seedling vigour index. Additionally, the malondialdehyde level, total polyphenol content, total flavonoid content, and total antioxidant capacity were analysed. Plasma treatment displayed varying effects on the morphological characteristics and antioxidant activity of the tested cultivars, which were influenced by treatment duration and cultivar. A positive effect of plasma treatment on seedling length, seedling vigour index, and root–shoot ratio was observed in flax cultivar ‘N-9/62/K3/B’ in all periods and in variants T2 and T3. Conversely, the wheat cultivar ‘Granny’ showed variable results, and the oat cultivar ‘Risto’ showed variable negative results in regards to mean root length and mean shoot length after plasma treatment. The indicators of oxidative stress and antioxidant capacity were affected in all the cultivars studied. A positive effect of plasma treatment on these indicators was observed in the wheat cultivar ‘Granny’, while flax cultivar ‘N-9/62/K3/B’ exhibited inconsistent results. While in cereals, a decrease in malondialdehyde content after plasma treatment was associated with an increase in polyphenol and flavonoid content as the treatment duration increased, small-seeded species responded somewhat differently. The rapeseed cultivar ‘Skrivenskij’ and flax cultivar ‘N-9/62/K3/B’ showed an increase in polyphenol and flavonoid content following a decrease in malondialdehyde levels. This study highlights the potential of low-temperature plasma treatment for long-term-stored seeds and its applicability to plant genetic resources. The findings emphasize the need for the further optimization of low-temperature plasma treatment conditions for different plant species and cultivars. Full article

Entomopathogenic fungi are a group of fungi that infect and kill insects to obtain nutrients, thereby contributing to the natural regulation of insect populations. In recent years, they have been increasingly utilized as biological control agents, particularly in response to the rising prevalence of pesticide-resistant pests in agricultural systems. Representative examples include Beauveria bassiana and Metarhizium anisopliae, which are regarded as natural enemies of pests in agroecosystems. Since the first report of Korean oak wilt disease in 2004, the disease has continuously spread across the country and causes severe damage to deciduous oak species, especially Quercus mongolica. Although many efforts have been made to effectively control the disease, including chemical treatments, the control efficacy was shown to be low, and given the environmental side effects arising from the use of insecticides, there has been a demand for alternative control strategies. Integrated Pest Management in forests promotes ecological sustainability by reducing chemical pesticide use, conserving biodiversity, and enhancing long-term forest health. In this study, to mitigate issues with disease management strategies, assessments were made on three entomopathogenic fungi, B. bassiana, M. anisopliae, and Purpureocillium lilacinum, as potential biological control agents against oak wilt disease and its insect vector, Platypus koryoensis. In this regard, we investigated the insecticidal efficacy and LT₅₀ of each entomopathogenic fungus, and the results showed that all three entomopathogenic fungal strains exhibited fast insecticidal effects against the insect vector, P. koryoensis, with M. anisopliae showing the fastest action, recording a lethal time to 50% mortality (LT₅₀) of 58.7 h. The spores of M. anisopliae were found to be sensitive to high temperatures, while demonstrating a relatively high germination rate under UV exposure and strong initial germination ability at low temperatures. Full article

Sweet corn is highly susceptible to low temperatures, especially during seed germination, which severely affects plant growth and crop yield. This study used 100 sweet corn micro-core germplasms to evaluate two key germination traits under cold stress: seed storage material utilization efficiency (SRUE) and mobilization weight (WMSR). To investigate the genetic basis of cold germination in sweet corn, we selected the BLINK model for GWAS due to its ability to minimize false positives. A total of nine SNPs were found to be significantly associated with cold germination. These SNPs explained between 9.8% and 17.2% of the phenotypic variance (PVE). Within the confidence interval, 63 functionally annotated genes were identified. Fourteen candidate genes associated with cold germination were identified through GO functional analysis and the functional expression of homologous genes. A literature analysis indicated that these genes are primarily involved in seed germination, cold tolerance, and responses to other abiotic stresses. These findings enhance our understanding of the genetic and molecular mechanisms underlying cold germination, establishing a theoretical foundation for breeding cold-tolerant sweet corn varieties. Full article

Sprouts have many advantages, such as high nutritional value and simple cultivation conditions. In recent years, the loss rate of sprouts due to microbial contamination has been as high as 40%, and it is necessary to strengthen microbial control technology to reduce such losses. Current microbial control methods have issues such as a narrow bactericidal spectrum and high cost and contamination, whereas slightly acidic electrolyzed water (SAEW), as a new type of disinfectant, can solve these problems. In the present study, the efficacy of SAEW treatments in the disinfection of oat sprouts during germination and washing was evaluated at 25 °C and 4 °C compared to a TW control group. The results showed that compared to the TW control group, the Escherichia coli detection rates were significantly decreased by 2.32, 4.44 and 5.55 log₁₀ CFU/g after soaking, undergoing germination for 60 h and washing with SAEW at 4 °C. This indicated that the 4 °C + SAEW treatment had a favorable bactericidal effect on the whole process of oat sprout washing. This result was demonstrated by scanning electron microscopy (SEM). In addition, for natural colony counts in oat sprouts, the 4 °C + SAEW treatment also showed strong bactericidal ability. Therefore, the application of SAEW combined with low temperature stress treatment in sprout production and processing has high potential. Full article

Panax ginseng Meyer is one of the most popular traditional medicinal plants in Korea. Since ginseng seeds are morpho-physiologically dormant and have a very short lifespan, the harvested seeds need outdoor warm and cold stratification for 100 days each. The seeds were covered by a fruit coat (endocarp), which opened during warm stratification. Farmers must, therefore, dehisce (open the endocarp) seeds annually. The conditions for embryo growth, dehiscence percentage, and endocarp hardness were temperature, watering, stratification substances, solution scarification, and microbial inoculation of the seed endocarp. Watering, temperature (17.5 °C), and aeration are crucial for embryo growth as a germination condition. Moreover, microbial-mediated endocarp decomposition is necessary for dehiscence and embryonic development. This study suggests that a combination of embryo growth and microbial-mediated decomposition of the endocarp during warm stratification is a prerequisite for the dehiscence of ginseng seeds, implying physical and morpho-physiological dormancy. Any microbes (fungi, actinomycetes, and bacteria) tested with high or low cellulose-decomposing ability increased the dehiscence percentage by 66% compared to the untreated control. Seeds of three varieties of P. ginseng and one variety of P. quinquefolius were successfully dehisced by fungal inoculation of seeds. This approach opens the door for year-round indoor dehiscence of ginseng seeds without substrates, such as sand. Full article

The ability of seeds to germinate under a wide range of environmental conditions is an important characteristic of invasive alien plant species. Solanum rostratum Dunal, has been widely distributed in the Northeast and Northwest of China and is causing huge damage to the local agricultural production. Studies on seed germination and response among populations to environmental stress may assist in revealing the adaptability of invasive plants and how they cope with climate change. In this study, we collected seeds from five invasive plant populations of S. rostratum, with intervals of over 3000 km between them, distributed in different habitats and climate zones. We measured the differences in seed traits between populations and studied the trends in germination responses of S. rostratum seeds under diverse abiotic stress conditions. The weight and size of S. rostratum seeds distributed in Northeast China were significantly greater than those distributed in Northwest China; for the response of S. rostratum seed germination to environmental factors, seeds from arid and extremely arid areas of Northwest China had greater tolerance to high temperatures and osmotic stress, while seeds from semi-arid areas of Northeast China were more sensitive to low temperatures and high salt stress. Overall, the germination of S. rostratum seeds responded differently to various environmental stress factors, reflecting the ability of S. rostratum to occupy germination sites under low resource competition. Given the rapid changes in the global climate, our findings provide new insights into the seed adaptation strategies of alien plants during the invasion process and the mechanisms involved. Full article

Low temperatures cause serious threat to rice seed emergence, which has become one of the main limiting factors in the production of direct seeding rice. It is of great importance to study the genes controlling low-temperature tolerance during seed germination and to mine the possible regulatory mechanism for developing new rice varieties with immense low-temperature germination ability. In the current research study, two types of mutants of nal11 and gasr9, derived from the WT (wild type) ZH11, were used for the analysis of low-temperature germinability. The results showed that the nal11 and gasr9 mutants displayed no significant difference in germination rate with ZH11 at room temperature, but the mutants showed significantly lower germination rates, germination potential and germination index, and slowed seedling growth in the simulated direct seeding experiments at low temperatures compared to ZH11. Additionally, the activity of POD, SOD, CAT, and anti-superoxide anion radial activity were significantly reduced, but the levels of MDA and H₂O₂ were significantly higher in the nal11 and gasr9 mutant seeds that were germinated at low temperatures compared to ZH11. Further analysis revealed that the levels of total active GA, especially GA4 and GA7, were significantly lower in the nal11 and gasr9 mutants than that in ZH11 during low-temperature germination. Based on qRT-PCR analysis, the expression levels of some GA synthesis-related genes were higher, whereas some were lower in the nal11 and gasr9 mutants than those in ZH11, however, the GA metabolism-related genes OsGA2ox8 and OsGA2ox10 and the GA signaling negative regulator gene SLR1 were significantly up-regulated in both nal11 and gasr9 mutants at several time points during low-temperature germination. This may explain the lower GA levels in the nal11 and gasr9 mutants. Furthermore, the interaction between the OsNAL11 and OsGASR9 proteins was confirmed by Y2H, LUC, and Co-IP assays. This study provides preliminary insights into the regulatory mechanism of the OsNAL11 and OsGASR9 genes, which control the low-temperature germination of rice seeds by affecting the GA pathway. Our study will provide the basis for further mining the molecular mechanisms of low-temperature germination in rice and valuable theoretical reference for breeding varieties with strong low-temperature germinability. Full article

This study investigated the germination response to temperature of seeds of nine Arabidopsis thaliana ecotypes. They are characterized by a similar temperature dependency of seed germination, and 10 °C and 29 °C were found to be suboptimal low and high temperatures for all nine ecotypes, even though they originated from regions with diverse climates. We tested the potential of four PGPR strains from the genera Pseudomonas and Bacillus to stimulate seed germination in the two ecotypes under these suboptimal conditions. Biopriming of seeds with only the biofilm-forming strain Pseudomonas putida KT2440 significantly increased the germination of Cape Verde Islands (Cvi-0) seeds at 10 °C. However, biopriming did not significantly improve the germination of seeds of the widely utilized ecotype Columbia 0 (Col-0) at any of the two tested temperatures. To functionally investigate the role of KT2440’s biofilm formation in the stimulation of seed germination, we used mutants with compromised biofilm-forming abilities. These bacterial mutants had a reduced ability to stimulate the germination of Cvi-0 seeds compared to wild-type KT2440, highlighting the importance of biofilm formation in promoting germination. These findings highlight the potential of PGPR-based biopriming for enhancing seed germination at low temperatures. Full article

Onopordum nervosum subsp. platylepis Murb. is an Asteraceae species found in Tunisia, Algeria, and Libya. It has been studied for its potential use as a vegetable rennet alternative to animal-derived rennet, making it important to understand its germination characteristics. This species often shows low germinability due to dormancy, which limits its large-scale cultivation. In preliminary experiments, many factors were analyzed to evaluate the seed germination of this thistle including physical stratification with abrasive paper and high-temperature water, chemical treatments with hydrogen peroxide (H₂O₂) or sulfuric acid (H₂SO₄), and the exogenous use of the growth regulator gibberellic acid (GA₃). Based on the obtained results and subsequent analysis, GA₃ and cold stratification durations were selected for the second experiment, which used a full factorial RSM design with three levels for each factor. Additionally, the total polyphenol content (TPC), total flavonoid content (TFC), condensed tannin content (CTC), and DPPH assay were analyzed during the optimization process and for ungerminated seeds. The findings revealed that 14 days of cold stratification followed by 750 ppm GA₃ was the most efficient method for breaking the dormancy of these thistle seeds. The highest TPC was recorded in ungerminated seeds. However, germinated Onopordum nervosum ssp. platylepis seeds showed higher levels of TFC and CTC (14.83 mg QE/g DW and 6.49 mg EC/g DW, respectively) compared to the non-germinated ones and demonstrated the greatest potency in inhibiting free radicals (DPPH EC₅₀ = 0.018 mg/mL) at the identified optimal germination conditions. Ungerminated seeds indicated significant phenolic content (TPC) and a limited ability to reduce oxidants, which could explain their low germination percentage. Our findings on the seed germination and dormancy characteristics of this endemic thistle will aid in the protection and development of its germplasm. Full article

Rice (Oryza sativa L.) cultivation using direct seeding is susceptible to chilling stress, particularly during seed germination and early seedling growth in the early season of a double cropping system. Alternatively, seed priming with various plant growth-promoting hormones is an effective technique to promote rapid and uniform emergence under chilling stress. Therefore, we evaluated the impact of gibberellin A3 (GA₃) and brassinolide (BR) priming on rice seed emergence, examining their proteomic responses under low-temperature conditions. Results indicated that GA₃ and BR increased the seed germination rate by 22.67% and 7.33% at 72 h and 35% and 15% at 96 h compared to the control (CK), respectively. Furthermore, proteomic analysis identified 2551, 2614, and 2592 differentially expressed proteins (DEPs) in GA, BR, and CK, respectively. Among them, GA exhibited 84 upregulated and 260 downregulated DEPs, while BR showed 112 upregulated and 102 downregulated DEPs, and CK had 123 upregulated and 81 downregulated DEPs. Notably, under chilling stress, both GA₃ and BR are involved in peroxide metabolism, phenylpropanoid biosynthesis, and inositol phosphate metabolism, enhancing antioxidant capacity and providing energy substances for germination. In addition, GA₃ triggers the specific regulation of stress responsive protein activation, GTP activation, and ascorbic acid biosynthesis and promotes the stability and integrity of cell membranes, as well as the synthesis of cell walls, providing physical defense for seeds to resist low temperatures. At the same time, BR triggers specific involvement in ribosome synthesis and amino acid synthesis, promoting biosynthetic ability and metabolic regulation to maintain plant life activities under low-temperature stress. Furthermore, the various genes’ expression (OsJ_16716, OsPAL1, RINO1) confirmed GA₃ and BR involved in peroxide metabolism, phenylpropanoid biosynthesis, and inositol phosphate metabolism, enhancing antioxidant capacity and providing energy substances for germination. This study provides valuable insights into how rice seed embryo responds to and tolerates chilling stress with GA₃ seed priming. Full article

Seed quality declines during storage depending on relative humidity, temperature, and oxygen concentration. Low-oxygen atmospheres significantly enhanced the germination and vigor of seeds during storage in laboratory-scale experiments. Low-oxygen atmospheres include self-modified atmospheres, where gas composition changes due to microbial respiration and oxidative processes, as well as modified atmospheres, where gas composition is initially altered from an external source without further adjustments. However, the potential of low-oxygen atmospheres to preserve the quality of maize (Zea mays) seeds in bags of 25–50 kg capacity, like those employed by seed companies and small-scale farmers, remains underexplored, hindering a broader adoption of this storage technology. Our study assessed the feasibility of applying low-oxygen atmospheres for seed storage on the pilot scale, i.e., hermetic containers of 25 kg capacity made of polyethylene and polyamide, under controlled conditions. We first evaluated the ability of the hermetic containers to maintain low oxygen levels over time. Then, we compared the germination and vigor of seeds stored in the hermetic containers under modified and self-modified atmospheres with those stored in traditional poly-paper bags under normal atmospheric conditions. The seeds had 14% moisture content (wet basis) and were stored at 25 °C and 10 °C. Maintaining low oxygen levels in polyethylene–polyamide bags was feasible. Moreover, at 25 °C, modified and self-modified atmospheres maintained higher germination values (95.8% and 94.4%, respectively) compared to traditional storage (68.3%), and both were as effective as refrigeration (97.6%). However, refrigeration was better for preserving seed vigor, with radicle emergence values of 85.2% in self-modified atmospheres and 78.9% in modified atmospheres, compared to 65.0% and 61.2%, respectively, at 25 °C. In conclusion, the advantages of modified atmospheres observed in laboratory-scale studies are achievable on a larger scale with a proper container design, advancing the prospects for the practical application of this technology for the seed industry and small farmers. Full article

Low temperature is the most common abiotic factor that usually occurs during the seed germination of alfalfa (Medicago sativa L.). However, the potential regulatory mechanisms involved in alfalfa seed germination under low temperature stress are still ambiguous. Therefore, to determine the relevant key genes and pathways, the phenotypic and transcriptomic analyses of low-temperature sensitive (Instict) and low-temperature tolerant (Sardi10) alfalfa were conducted at 6 and 15 h of seed germination under normal (20 °C) and low (10 °C) temperature conditions. Germination phenotypic results showed that Sardi10 had the strongest germination ability under low temperatures, which was manifested by the higher germination-related indicators. Further transcriptome analysis indicated that differentially expressed genes were mainly enriched in galactose metabolism and carbon metabolism pathways, which were the most commonly enriched in two alfalfa genotypes. Additionally, fatty acid metabolism and glutathione metabolism pathways were preferably enriched in Sardi10 alfalfa. The Weighted Gene Co-Expression Network Analysis (WGCNA) suggested that genes were closely related to galactose metabolism, fatty acid metabolism, and glutathione metabolism in Sardi10 alfalfa at the module with the highest correlation (6 h of germination under low temperature). Finally, qRT-PCR analysis further validated the related genes involved in the above pathways, which might play crucial roles in regulating seed germination of alfalfa under low temperature conditions. These findings provide new insights into the molecular mechanisms of seed germination underlying the low temperature stress in alfalfa. Full article

The long-term storage of coal gangue (CG) mountains causes serious environmental problems such as water and air pollution. Thus, sustainable reclamation practices are urgently needed to minimize the environmental impacts brought by CG mountains. Pikovskaya medium was employed to screen microorganisms, which were subsequently utilized to promote the solubilization of CG. XRF, SEM, XRD, and HPLC techniques were employed to characterize the CG before and after bacterial treatment. In this study, we have successfully isolated and purified a bacterial strain, identified as Stenotrophomonas bentonitica BII-R7, which possesses the ability to facilitate the solubilization of nutrient elements from CG. Factors including initial inoculation ratio, incubation time, CG particle size, CG concentration, pH, and temperature were examined to investigate their effects on the biosolubilization of CG. Furthermore, the mechanism underlying the CG solubilization was also probed. Our data demonstrated that low-molecular-weight organic acids, such as acetic acid and formic acid, may harbor a crucial role in promoting the solubilization of CG. Lastly, we found that Stenotrophomonas bentonitica BII-R7, in conjugation with CG, can increase the alfalfa seed germination percentage and promote the growth of alfalfa. Together, these data provide evidence that bacterial-treated CG can be utilized for soil improvement and land reclamation. Full article

Dendrobium officinale is a valuable traditional Chinese herbal plant that is both medicinal and edible. However, the yield of wild Dendrobium officinale is limited. Adverse stress affects the growth, development, and yield of plants, among which low temperature is the primary limiting factor for introducing Dendrobium officinale to high-latitude areas and expanding the planting area. Therefore, this study aims to explore the variations in growth ability, cold resistance, and contents of bioactive compounds among different Dendrobium officinale strains. Four strains of Dendrobium officinale were selected as experimental materials and were subjected to low-temperature stress (4 °C). The agronomic traits, physiological indices, as well as the expressions of cold resistance-related genes (HSP70, DcPP2C5, DoCDPK1, and DoCDPK6) in the roots and leaves of Dendrobium officinale, were determined. The contents of bioactive compounds, including polysaccharides, flavonoids, and phenols were also measured. Compared with the other strains, Xianju had the highest seed germination and transplantation-related survival rates. Under low-temperature stress, Xianju exhibited the strongest cold resistance ability, as revealed by the changes in water contents, chlorophyll levels, electrical conductivities, enzyme activities, and expressions of the cold resistance-related genes. Additionally, the polysaccharide content of Xianju increased the most, while the stem flavonoid and leaf phenol contents were elevated in all four strains under cold treatment. Therefore, selecting excellent performing strains is expected to expand the planting area, improve the yield, and increase the economic benefits of Dendrobium officinale in high latitude areas with lower temperatures. Full article