Aged Seeds Research Articles

Impact of accelerated aging on seed quality, seed coat physical structure and antioxidant enzyme activity of Maize (Zea mays L.).

Aging induces many deteriorative changes to seeds during storage like protein degradation, enzyme inactivation and loss of membrane integrity. In this study, we investigate the impact of accelerated aging on seed quality, seed coat physical structure and antioxidant enzyme activity of maize. Three genotypes African Tall, MAH 14-5 and a local landrace were selected and artificially aged for 96 and 120 h. The aging process led to a decrease in germination, vigour, and total dehydrogenase in seeds, while the electrical conductivity of seed leachates increased, indicating a decline in seed quality. Additionally, there was a variation in the microsculpture pattern of seed coats between genotypes. There was an accumulation of damage on the seed coat surface as the seeds aged and higher damage occurred in African Tall followed by MAH 14-5 and local landrace. Higher catalase, superoxide dismutase, peroxidase and polyphenol oxidase activity were reported in the seed coat of Local landrace and MAH 14-5 that resisted aging and deterioration while, lower catalase, superoxide dismutase, peroxidase and polyphenol oxidase activity was reported in African Tall seed coat that deteriorated during aging. Decrease antioxidant activity in aged seeds might be a possible cause of seed deterioration due to the accumulation of free radicals. Thus, these results clearly show the influence of seed coat structure and antioxidant activity on seed quality during aging.

Evaluation of memory drought stress effects on storage compounds seedlings of cotton (Gossypium hirsutum) and in-silico analysis of glutathione reductase

In breeding programs, stress memory in plants can develop drought stress tolerance. Memory stress, as an approach, can keep stress data by activating tolerance mechanisms. This research was conducted to evaluate some physiologically effective mechanisms in inducing memory drought stress in the seeds that were exposed to water stress three times in four treatments including rainfed, 33%, 66%, and 100% of field capacity (FC). After the production of the seeds, the third-generation seeds were placed under different irrigation treatments, seed and seedling traits, starch to carbohydrate ratio in seed, protein concentration and glutathione reductase were investigatied in a factorial format based on a randomized complete block design with three replications. Results showed that percentage of changes from the lowest to the highest value for traits including seed vigor, seed endosperm weight, seed coat weight, accelerated aging, cold test, seedling biomass and seedling length were 25, 37, 65, 65, 55, 77, 55, 65 and 79, respectively and germination uniformity was 3.9 times higher than the lowest amount. According to the deterioration percentage, seed vigor and the percentage of seed germination in cold test data, it can be reported that seed production by 100% FC was not appropriate for rainfed plots. However, considering the the appropriate results in the percentage of germination for a cold test, germination uniformity percentage, and the lowest accelerated aging seeds, seed production under the rainfed conditions with 33% FC watering can be recommended. In-silico analysis was coducted on Glutathione reductase (GR) enzymes in Gossypium hirsutum. It is clear that GR has a Redox-active site and NADPH binding, and it interacts with Glutathione S transferase (GST). So, memory drought stress through inducing physiological drought tolerance mechanisms such as starch-to-carbohydrate ratio and GR can determine the suitable pattern for seed production for rainfed and low rainfall regions in a breeding program. Our study thus illustrated that seed reprduction under 33% FC equipped cotton with the tolerance against under draught stress from the seedling stage. This process is done through activating glutathione reductase and balancing the ratio of starch to carbohydrates concentration.

Physiological Responses of Different Aged Rice Seeds to Osmopriming with PEG 6000

The objective of this research was to compare the quality of different aged rice seed after priming. The rice seeds were deteriorated by accelerated aging method at 44 °C and relative humidity 100 %, in different periods for 0 (without accelerated aging), 1, 2, 3, and 4 days. Then, the germination of rice seeds of different ages were induced by soaking in 30% of PEG 6000 solution at room temperature for 24 hours. After that, the rice seeds were dried in a hot air oven at 35 °C for 10 hours until the moisture content was close to the initial moisture. Finally, these treated rice seeds were examined for the seed quality of various characteristics such as seed germination rate (planted in the laboratory and field conditions), germination index, speed of germination, and electrical conductivity of solution used for soaking seeds. The results showed that the electrical conductivity of all different aged seeds decreased after priming. For the field of germination and germination uniformity, it was found that the seeds with different rates of deterioration showed different responses to the priming. Aged seeds with germination rates of 12 and 33 percent germination were able to induce germination rate by 27 and 48 percent, respectively, while aged seeds with higher deterioration rate had a decreased response.

Overexpression of protection of telomeres 1 (POT1), a single-stranded DNA-binding proteins in alfalfa (Medicago sativa), enhances seed vigor

Extensive bodies of research are dedicated to the study of seed aging with a particular focus on the roles of reactive oxygen species (ROS), and the ensuing oxidative damage during storage, as a primary cause of seed vigor decreasing. ROS diffuse to the nucleus and damage the telomeres, resulting in a loss of genetic integrity. Protection of telomeres 1 (POT1) is a telomeric protein that binds to the telomere region, and plays an essential role in maintaining genomic stability in plants. In this study, there were totally four MsPOT1 genes obtained from alfalfa genome. Expression analysis of four MsPOT1 genes in germinated seed presented the different expressions. Four MsPOT1 genes displayed high expression levels at the early stage of seed germination, Among the four POT1 genes, it was found that MS. gene040108 was significantly up-regulated in the early germination stage of CK seeds, but down-regulated in aged seeds. RT-qPCR assays and RNA-seq data revealed that MsPOT1-X gene was significantly induced by seed aging treatment. Transgenic seeds overexpressing MsPOT1-X gene in Arabidopsis thaliana and Medicago trunctula exhibited enhanced seed vigor, telomere length, telomerase activity associated with reduced H2O2 content. These results would provide a new way to understand aging stress-responsive MsPOT1 genes for genetic improvement of seed vigor. Although a key gene regulating seed vigor was identified in this study, the specific mechanism of MsPOT1-X gene regulating seed vigor needs to be further explored.

Reactive nitrogen species act as the enhancers of glutathione pool in embryonic axes of apple seeds subjected to accelerated ageing

Main conclusionReactive nitrogen species mitigate the deteriorative effect of accelerated seed ageing by affecting the glutathione concentration and activities of GR and GPX-like.The treatment of apple (Malus domestica Borkh.) embryos isolated from accelerated aged seeds with nitric oxide-derived compounds increases their vigour and is linked to the alleviation of the negative effect of excessive oxidation processes. Reduced form of glutathione (GSH) is involved in the maintenance of redox potential. Glutathione peroxidase-like (GPX-like) uses GSH and converts it to oxidised form (GSSG), while glutathione reductase (GR) reduces GSSG into GSH. The aim of this work was to investigate the impact of the short-time NOx treatment of embryos isolated from apple seeds subjected to accelerated ageing on glutathione-related parameters. Apple seeds were subjected to accelerated ageing for 7, 14 or 21 days. Isolated embryos were shortly treated with NOx and cultured for 48 h. During ageing, in the axes of apple embryos, GSH and GSSG levels as well as half-cell reduction potential remained stable, while GR and GPX-like activities decreased. However, the positive effect of NOx in the vigour preservation of embryos isolated from prolonged aged seeds is linked to the increased total glutathione pool, and above all, higher GSH content. Moreover, NOx increased the level of transcripts encoding GPX-like and stimulated enzymatic activity. The obtained results indicate that high seed vigour related to the mode of action of NO and its derivatives is closely linked to the maintenance of higher GSH levels.

Arabidopsis DNA glycosylase MBD4L improves recovery of aged seeds.

DNA glycosylases initiate the base excision repair (BER) pathway by catalyzing the removal of damaged or mismatched bases from DNA. The Arabidopsis DNA glycosylase methyl-CpG-binding domain protein 4 like (MBD4L) is a nuclear enzyme triggering BER in response to the genotoxic agents 5-fluorouracil and 5-bromouracil. To date, the involvement of MBD4L in plant physiological processes has not been analyzed. To address this, we studied the enzyme functions in seeds. We found that imbibition induced the MBD4L gene expression by generating two alternative transcripts, MBD4L.3 and MBD4L.4. Gene activation was stronger in aged than in non-aged seeds. Seeds from mbd4l-1 mutants displayed germination failures when maintained under control or ageing conditions, while 35S:MBD4L.3/mbd4l-1 and 35S:MBD4L.4/mbd4l-1 seeds reversed these phenotypes. Seed nuclear DNA repair, assessed by comet assays, was exacerbated in an MBD4L-dependent manner at 24 h post-imbibition. Under this condition, the BER genes ARP, APE1L, and LIG1 showed higher expression in 35S:MBD4L.3/mbd4l-1 and 35S:MBD4L.4/mbd4l-1 than in mbd4l-1 seeds, suggesting that these components could coordinate with MBD4L to repair damaged DNA bases in seeds. Interestingly, the ATM, ATR, BRCA1, RAD51, and WEE1 genes associated with the DNA damage response (DDR) pathway were activated in mbd4l-1, but not in 35S:MBD4L.3/mbd4l-1 or 35S:MBD4L.4/mbd4l-1 seeds. These results indicate that MBD4L is a key enzyme of a BER cascade that operates during seed imbibition, whose deficiency would cause genomic damage detected by DDR, generating a delay or reduction in germination.

Physiological, Biochemical, and Ultrastructural Changes in Naturally Aged Sweet Corn Seeds

Due to low starch content and poor seed vigor, sweet corn seeds exhibit poor storage stability. Therefore, understanding the physiological and biochemical changes in seeds after natural aging is crucial for assessing seed status and extending the storage period. This study aims to investigate the physiological, biochemical, and ultrastructural changes in aged seeds of different genotypes. An eight-month natural aging experiment was conducted on 10 sweet corn inbred lines. The results showed an obvious decrease in germination potential, germination ratio, germination index, and vigor index after natural aging, and two inbred lines with stronger tolerance to natural aging were identified from the 10 inbred lines studied. In aged seeds, levels of gibberellin, abscisic acid, total protein, total starch, as well as activities of antioxidant enzymes, lipoxygenase, and amylase, and malondialdehyde (MDA) content, exhibited significant differences among inbred lines. Correlation analysis revealed a positive correlation among four seed vigor indices and a highly negative correlation between seed vigor indices and MDA content. Germination ratio, germination index, and vigor index displayed a highly negative correlation with lipoxygenase activity. Furthermore, starch granule decomposition was observed in the endosperm of low-vigor inbred lines, contrary to amylase activity. Thus, this study indicates variations in seed vigor, biochemical indicators, and the ultrastructure of aged sweet corn seeds among different genotypes. Both lower lipoxygenase activity and reduced MDA accumulation contribute to seed resistance to aging.

Non-destructive Near-infrared Hyperspectral Imaging in Food Technologies with a Focus on Monitoring Seed Viability

Seed qualities including viability and germination significantly influence the quantity and the quality of harvest. Technological means to assess seed qualities and attributes of seed-derived food products are varied. This paper highlights the use of infrared hyperspectral imaging (NIR- HSI) in food quality control, authentication, safety, process monitoring, shelf-life prediction, ingredients analysis, allergens detection and food sorting and grading. It also shows a particular application of NIR-HSI for the monitoring of nutrient content of sprouts and germinated seeds for industrial processing of foods with high nutritional values. The paper further reviews the applications of NIR-HSI to predict seed viability and germination. The non-destructive, rapid, and high-throughput capability of NIR-HSI were demonstrated through research works combining the NIR-HSI technology with chemometrics tools to reach more than 90% prediction rate. These relatively high rates may depend on the storage conditions or the stringency of the artificial aging conditions applied to parts of the seeds. However, the NIR-HSI has also proven efficient using naturally aged seeds with the prediction rates up to 90% correct classification, demonstrating the high capability of the technology. In combination with advanced chemometrics tools, some components of emerging technologies such as traditional machine learning and deep learning models have been added to increase the efficiency of NIR_HSI. Overall, the research works reviewed in this paper and which cover several food crops and food products showed that NIR-HSI is set to reach new heights in monitoring seed viability for improved seed stock management, crop production and innovation in the food industry.

Physical and physiological quality of oat (Avena sativa L. cv. Turquesa) seeds

bjective: The objective of this study was to determine the physical and physiological quality of a batch of oat (Avena sativa L. cv. Turquesa) seeds. Design/Methodology/Approach: The following physical quality variables were evaluated: seed purity, weight of a thousand seeds, volumetric weight, and moisture content. Physiological quality was evaluated through a germination and emergence speed test, which also was used to measure seed vigor. A completely randomized experimental design, with factorial arrangement, and four repetitions was used. The factors analyzed were seed size (small and large) and aging (with and without aging). Results: The following results were recorded: 99.52% seed purity; 34.31 g weight of a thousand seeds; 54.80 kg hl-1 volumetric weight; and 6.50% moisture content. Regarding treatment germination, no significant differences were found between the seed size and the size × aging interaction (P = 0.422). The aging treatment reduced germination from 96.50% (unaged seeds) to 89.25% (aged seeds). The emergence speed did not show significant differences regarding seed size (P = 0.066) and size × aging interaction (P = 0.868). The aging treatment had a negative impact on the emergence rate. The aged seeds emerged at a 15.55 plants d-1 speed, while unaged seeds reached a 17.88 plants d-1 speed. Study Limitations/Implications: This study only evaluated one batch of oat seeds. Findings/Conclusions: The seeds have an adequate physical and physiological quality to establish oat crops. In addition, the seed batch was highly vigorous, because it maintained >80% germination rate after the aging treatment.

Physiological and Molecular Analysis of Soybean Seed Longevity and Validation of Candidate Markers

Background: Seed longevity is a major constraint in soybean seed production. The major focus of this study is to analyze the physiological and molecular changes associated with seed longevity and identify promising germplasm which are good storers for soybean breeding program. Methods: Nineteen genotypes were studied for seed longevity using accelerated ageing test and genetic integrity based on SSR marker data. Genotypes were clustered into distinct groups based on seed morphological and physiological parameters (Mahalanobis D2 analysis). SSR markers for seed longevity were validated in the germplasm. Result: Per cent reduction in germination after accelerated ageing was significantly and positively correlated with traits associated with seed storability such as seed length, seed width, seed thickness and 100 seed weight and negatively correlated with seedling vigour indices. Hence, it would be worthwhile to rely upon these parameters for enhancing the seed storability in soybean. Genetic integrity of the germplasm was evaluated based on SSR markers in accelerated ageing seeds. SSR markers (Satt 285, Satt 534, Satt 538, Satt 281, Satt 162, Satt 631 and Satt 371) revealed significant association for the seed longevity characters such as seed length, seed width, seed thickness and seed weight. Candidate markers (Satt 371, Satt 281, Satt162, Satt 285, Satt 534) which can differentiate the soybean genotypes for storability have been identified in this study. The genotypes were grouped into seven clusters with monogenotypic cluster III (PSPB23) having minimum reduction in germination after accelerated ageing.

Invigorative potential assessment of priming agents through germination and various seedling attributes of artificially aged seeds in carrot (Daucus carota L.)

Invigorative potential assessment of priming agents through germination and various seedling attributes of artificially aged seeds in carrot (Daucus carota L.)

The association of protein-bound methionine sulfoxide with proteomic basis for aging in beech seeds

BackgroundEuropean beech (Fagus sylvatica L.) trees produce seeds irregularly; therefore, it is necessary to store beech seeds for forestation. Despite the acquisition of desiccation tolerance during development, beech seeds are classified as intermediate because they lose viability during long-term storage faster than typical orthodox seeds. In this study, beech seeds stored for short (3 years) or long (20 years) periods under optimal conditions and displaying 92 and 30% germination capacity, respectively, were compared.ResultsAged seeds displayed increased membrane damage, manifested as electrolyte leakage and lipid peroxidation levels. Analyses have been based on embryonic axes, which contained higher levels of reactive oxygen species (ROS) and higher levels of protein-bound methionine sulfoxide (MetO) in aged seeds. Using label-free quantitative proteomics, 3,949 proteins were identified, of which 2,442 were reliably quantified pointing to 24 more abundant proteins and 35 less abundant proteins in beech seeds under long-term storage conditions. Functional analyses based on gene ontology annotations revealed that nucleic acid binding activity (molecular function), ribosome organization or biogenesis and transmembrane transport (cellular processes), translational proteins (protein class) and membranous anatomical entities (cellular compartment) were affected in aged seeds. To verify whether MetO, the oxidative posttranslational modification of proteins that can be reversed via the action of methionine sulfoxide reductase (Msr) enzymes, is involved in the aging of beech seeds, we identified and quantified 226 MetO-containing proteins, among which 9 and 19 exhibited significantly up- and downregulated MetO levels, respectively, in beech seeds under long-term storage conditions. Several Msr isoforms were identified and recognized as MsrA1-like, MsrA4, MsrB5 and MsrB5-like in beech seeds. Only MsrA1-like displayed decreased abundance in aged seeds.ConclusionsWe demonstrated that the loss of membrane integrity reflected in the elevated abundance of membrane proteins had a higher impact on seed aging progress than the MetO/Msr system. Proteome analyses enabled us to propose protein Sec61 and glyceraldehyde-3-phosphate dehydrogenase as potential longevity modulators in beech seeds.

Nano zinc oxide mediated resuscitation of aged Cajanus cajan via modulating aquaporin, cell cycle regulatory genes and hormonal responses.

Nanoparticle pretreatment improved the health ofaged Cajanus cajan seeds viz., regulation ofredox status, gene expression, andrestoration ofhormonal homeostasis. Ageing deteriorates the quality of seeds by lowering their vigor and viability, and terminating with loss of germination. These days, nanotechnology has been seen to revolutionize the agricultural sectors, and particularly nano zinc oxide (nZnO) has gained considerable interests due to its distinctive properties. The aim of the present work was to decipher the possibilities of using nZnO to rejuvenate accelerated aged (AA) seeds of Cajanus cajan. Both chemically (CnZnO) and green (GnZnO; synthesized using Moringa oleifera) fabricated nZnOs were characterized via standard techniques to interpret their purity, size, and shape. Experimental results revealed erratic germination with a decline in viability and membrane stability as outcomes of reactive oxygen intermediate (ROI) buildup in AA seeds. Application of nZnO substantially rebated the accrual of ROI, along with enhanced production of antioxidants, α-amylase activity, total sugar, protein and DNA content. Higher level of zinc was assessed qualitatively/ histologically and quantitatively in nZnO pulsed AA seeds, supporting germination without inducing toxicity. Meantime, augmentation in the gibberellic acid with a simultaneous reduction in the abscisic acid level were noted in nZnO invigorated seeds than that determined in the AA seeds, suggesting possible involvement of ROI in hormonal signalling. Furthermore, nZnO-subjected AA seeds unveiled differential expression of aquaporins and cell cycle regulatory genes. Summarizing, among CnZnO and GnZnO, later one holds better potential for a revival of AA seeds of Cajanus cajan by providing considerable tolerance against ageing-associated deterioration via recouping the cellular redox homeostasis, hormonal signaling, and alteration in expression patterns of aquaporin and cell cycle regulatory genes.

Aging-Induced Reduction in Safflower Seed Germination via Impaired Energy Metabolism and Genetic Integrity Is Partially Restored by Sucrose and DA-6 Treatment.

Seed storage underpins global agriculture and the seed trade and revealing the mechanisms of seed aging is essential for enhancing seed longevity management. Safflower is a multipurpose oil crop, rich in unsaturated fatty acids that are at high risk of peroxidation as a contributory factor to seed aging. However, the molecular mechanisms responsible for safflower seed viability loss are not yet elucidated. We used controlled deterioration (CDT) conditions of 60% relative humidity and 50 °C to reduce germination in freshly harvested safflower seeds and analyzed aged seeds using biochemical and molecular techniques. While seed malondialdehyde (MDA) and fatty acid content increased significantly during CDT, catalase activity and soluble sugar content decreased. KEGG analysis of gene function and qPCR validation indicated that aging severely impaired several key functional and biosynthetic pathways including glycolysis, fatty acid metabolism, antioxidant activity, and DNA replication and repair. Furthermore, exogenous sucrose and diethyl aminoethyl hexanoate (DA-6) treatment partially promoted germination in aged seeds, further demonstrating the vital role of impaired sugar and fatty acid metabolism during the aging and recovery processes. We concluded that energy metabolism and genetic integrity are impaired during aging, which contributes to the loss of seed vigor. Such energy metabolic pathways as glycolysis, fatty acid degradation, and the tricarboxylic acid cycle (TCA) are impaired, especially fatty acids produced by the hydrolysis of triacylglycerols during aging, as they are not efficiently converted to sucrose via the glyoxylate cycle to provide energy supply for safflower seed germination and seedling growth. At the same time, the reduced capacity for nucleotide synthesis capacity and the deterioration of DNA repair ability further aggravate the damage to DNA, reducing seed vitality.

The Effects of Storage Conditions on Seed Deterioration and Ageing: How to Improve Seed Longevity

Seeds are classified as either: orthodox, seeds that tolerate dehydration; recalcitrant, seeds that are high in moisture content and cannot withstand intensive desiccation; or intermediate, seeds that survive dehydration but die during dry storage at low temperatures. Seed lifespan depends on the seed category and also varies from one species to another. The rate of loss of vigor and viability of orthodox seeds depends mainly on temperature and seed moisture content (MC); the lower the MC and storage temperature, the longer the longevity. Ultimately, storage in liquid nitrogen or seed ultra-drying by well-adapted processes should allow for long-term storage. The ageing of orthodox seeds is associated with numerous forms of cellular and metabolic damage (membrane integrity, energy metabolism, and the impairment of DNA, RNA, and proteins) in which reactive oxygen species play a prominent role. Interestingly, priming treatment can reinvigorate aged seeds by restoring the antioxidant systems. The storage of recalcitrant seeds is very difficult since they must be placed in a wet medium to avoid dehydration and at temperatures low enough to prevent germination but warm enough to avoid chilling injury. A better understanding of the mechanisms involved in ageing is necessary to identify markers in order to estimate seed longevity.

The effects of pre-sowing treatments with aqueous allelopathic plant extracts on the germination parameters of aged soybean seeds

The aim of the paper was to examine the allelopathic influence of aqueous extracts of herbs and medicinal plants on the quality parameters of aged soybean seeds. The research was carried out at the Institute of Field and Vegetable Crops in Novi Sad on aged seeds of two soybean varieties, NS simba and NS viseris. The seeds were aged for 20 months. In order to determine the allelopathic effect, the seeds were primed in aqueous plant extracts: geranium (Geranium sinense), dill (Anethum graveolens), andy everlasting (Helichrysum arenarium), creeping thyme (Thymus serpyllum), celery (Apium graveolens), oregano (Origanum vulgare), basil (Ocimum basilicum), lemon balm (Melissa officinalis), rosemary (Rosmarinus officinalis), wormwood (Artemisia absinthium), peppermint (Mentha x piperita), sage (Salvia officinalis), and lavender (Lavandula angustifolia). The results show that it is not possible to talk about the universal application of a particular aqueous extract, because the effect of the allochemicals was significantly influenced by the variety. In the variety NS viseris, all aqueous extracts except Melissa officinalis, significantly reduced GE, GP, and VI. The most negative effect was achieved with the use of Apium graveolens, Thymus serpyllum, and Ocimum basilicum. Apium graveolens and Thymus serpyllum also had the greatest impact on quality reduction in the NS simba variety. However, in the NS simba variety, a significant increase in seed quality was achieved in addition to the reduction. The use of the aqueous extract of Salvia officinalis increased GE and GP by 13.7%, and VI by 10.21%. A positive effect was achieved with the use of Melissa officinalis. All aqueous extracts had a significant effect on T50 in both varieties, even the aqueous extracts that had a negative effect on GE and GP.

Seed priming as a method of preservation and restoration of sunflower seeds

The study focused on determining the preservative and restorative effects of seed priming with gibberellic acid (GA3) and potassium nitrate (KNO3) on sunflower seeds against deterioration. The seeds were immersed in different concentrations (0, 250, 500, and 1000 mg L−1) of GA3 and KNO3 solutions before and after being subjected to accelerated aging (AA). Unprimed seeds (NT) were used as control. The results showed that AA led to a reduction in germination percentage, germination index, and seedling growth parameters. However, seed primed with GA3 had a higher germination percentage after AA than NT. All seed primings shortened mean germination time and improved germination index. Seedling growth was stimulated by seed priming, and seed priming after AA produced more vigorous seedlings than primed seed before AA because they were severely affected by AA. In addition, hydration sufficiently induced the germination and seedling growth of aged seeds. A significant difference was found between GA3 and KNO3, and seeds were effectively protected from aging by GA3, while hydration promoted germination of aged seeds. Consequently, the recovery effect of seed priming was more pronounced than the conservative effect, and sunflower seeds should be primed with 500-1000 mg L−1 GA3 before storage or, if this is not possible, hydration improves the vitality and subsequent growth of aged sunflower seeds.

PEG-6000 Priming Improves Aged Soybean Seed Vigor via Carbon Metabolism, ROS Scavenging, Hormone Signaling, and Lignin Synthesis Regulation

Seed priming, a valuable seed pretreatment method widely employed in agricultural production, counteracts the decline in seed vigor attributed to aging and deterioration. However, PEG priming effectively enhances the vigor of aged soybean seeds. In this study, “TONGDOU13” soybean seeds were subjected to PEG-6000 priming at varying concentrations (10%, 20%, 30%, 40%) for three different durations (12 h, 24 h, 36 h). The results showed that a 24 h priming with 30% PEG-6000 significantly enhances the vigor of aged soybean seeds. To elucidate the mechanism underlying the heightened vigor resulting from PEG-6000 priming, we employed transcriptome sequencing and physiological–biochemical tests. Transcriptome sequencing analysis showed the significant down-regulation of carbon metabolism-related genes post PEG-6000 priming, which facilitated energetically efficient germination. Five peroxidase-encoding genes displayed significant up-regulation, promoting the conversion of coumaryl alcohol to hydroxy-phenyl lignin, a probable catalyst for augmented seed vigor. SOD and GST genes were significantly up-regulated, enhancing the scavenging ability of reactive oxygen species (ROS). The concurrent up-regulation of brassinolide (BR) and auxin (IAA) signals countered ABA signaling, thereby promoting aged seed germination. Further investigation included the measurements of antioxidant enzyme activity, hormone levels, and lignin content. Notably, primed aged seeds exhibited enhanced ROS scavenging ability, and increased lignin, BR, and IAA contents. Therefore, PEG priming may improve aged soybean seed vigor through the co-regulation of carbon metabolism, ROS scavenging, hormone signaling, and lignin synthesis. This study will be vital for preserving germplasm resources and reutilizing aged soybean seeds.

Oxidative stress is the active pathway in canola seed aging, the role of oxidative stress in the development of seedlings grown from aged canola seed

The widespread use of canola in the food sector has led to accelerated product growth, making it the second largest crop in the world. The analysis showed an increase in the content of proline (13.6%), H2O2 (12.7%), the levels of lipid peroxidation (30.7%), and antioxidant capacity (25.7%) in aged canola seed. The activity of CAT, SOD, and GPX enzymes increased by 1.40, 2.51, and 5.93 times respectively, while GR activity decreased by 8.8% in aged canola seed as compared to the control. An increase in GSSG content to 2.57 times and a decrease in GSH content of 0.76 times were observed in aged canola seeds. The increase in oxidative stress indices and the activity of antioxidant enzymes in canola seeds under accelerated aging indicate the role of free radicals in aging. Amylase enzyme activity increased 2.57 times in aged canola seed. Oxidative stress causes changes in the biological structures of seeds including cell membranes, lipids, pfroteins, and even in different tissue layers of seeds, which form different dimensions of the aging process. The analysis of canola seeds under accelerated aging showed that although aging reduced seed germination by 70%, the seedlings obtained from the seeds with the ability to germinate showed changes in the metabolic pathways of carbohydrates (0.26 times reduction) and proteins (1.36 times increase) of the seedlings. The phenolic compounds, flavonoid, and flavonol content of seedlings from aged seeds increased by 12.7%, 12.4%, and 12.1%, respectively. These seedlings showed significant changes in oxidative stress indexes compared to the control seedling.

SAM-GAN: An improved DCGAN for rice seed viability determination using near-infrared hyperspectral imaging

Viability is a significant indicator of rice seeds, affecting rice yield and quality. Existing viability determination methods cannot meet the requirements of rapidity, non-destructive and accuracy. In this study, near-infrared hyperspectral imaging was used to detect the viability of natural aging seeds. Generative Adversarial Network (GAN) is the main means of coping with Few-shot learning. Considering that natural aging seed samples were difficult to obtain and the number was scarce, this study used Spectral Angle Mapper Generative Adversarial Network (SAM-GAN) to generate rice seed spectral data based on the spectra of obtained natural aging seeds to solve the problem of sample scarcity. SAM-GAN is based on Deep Convolution GAN (DCGAN), introduced by SAM. SAM-GAN was compared with Wasserstein Generative Adversarial Nets with Gradient Penalty (WGAN-GP) and DCGAN, and the Convolutional Neural Network (CNN) model was established by three modeling methods: real data modeling, fake data modeling and mixed modeling of real data and fake data. The experimental results show that the accuracy of the CNN model established by mixing real data with fake data generated by SAM-GAN reaches nearly 100%. This study provides an effective method for rapid, non-destructive and accurate determination of rice seed viability with a limited sample number.