Germination Response Research Articles

The Physiological Response of Germination and Growth in Solanaceae Plants (Capsicum frutescens, Solanum melongena, Solanum lycopersicum) at Different Salinity Levels

High salinity causes osmotic stress and ion imbalance that can reduce plant productivity. Solanaceae can be developed for cultivation in saline land, but its growth is influenced by the type of species. This study aims to examine the tolerance level of three Solanaceae plants to salinity stress through observation of physiological responses of germination and growth. This study used a 3 x 4 factorial Completely Randomized Design (CRD). The first factor is salinity: 0 ppm, 2,500 ppm, 5,000 ppm and 7,500 ppm. The second factor is the Solanaceae species, namely Capsicum frutescens, Solanum melongena, and Solanum lycopersicum. Germination parameters include germination power, wet weight and dry weight. The growth parameters observed include plant height, root length, stem diameter, leaf area, number of leaves, wet weight of leaves, roots and stems and dry weight of leaves, roots and stems. The results of the study showed that C. frutescens is a plant that is more tolerant to salinity up to a concentration of 5,000 ppm when compared to S. melongena and S. lycopersicum whose tolerance is up to 2,500 ppm. Keywords: Germination, Salinity, Solanaceae, Vegetative Growth.

Seed germination response of the invasive Haloxylon persicum in Tunisia

Seed germination response of the invasive Haloxylon persicum in Tunisia

Differential germination responses of plump and shriveled seeds to environmental factors and storage conditions in Tamarix laxa Willd.

Tamarix laxa Willd. is a vital shrub widely distributed in arid and semi-arid regions. It serves as an excellent species for sand-fixing afforestation in saline-alkali and sandy desert lands and has medicinal properties for wind-dispelling and detoxifying. This plant produces two types of seeds: plump and shriveled. However, the effect of seed plumpness on germination has not been extensively studied. In this research, we found that 42% of the seeds in T. laxa were plump, and 58% were shriveled. We then investigated how different temperatures, light conditions, salt concentrations, and storage methods affect the germination of these seeds. Shriveled seeds were significantly smaller and had a lower germination percentage compared to plump seeds. T. laxa seeds exhibited a broad adaptability to temperature. Plump seeds showed over 90% germination at three different temperatures, whereas shriveled seeds had a 57% germination percentage at 15/30oC. Continuous darkness significantly reduced the germination percentage for both seed types. Although T. laxa seeds displayed some salt tolerance, high salt concentrations (0.6mol/L NaCl) markedly decreased their germination percentage. Freshly mature seeds initially had a 99% germination percentage. However, seeds stored at room temperature for 90 days nearly lost their viability. In contrast, seeds stored at -18 oC for 180 days maintained a germination percentage above 80%. Low-temperature storage effectively delayed the short-term loss of seed vitality. This study offers comprehensive insights into T. laxa seed germination, providing valuable information for desert restoration efforts.

Polyamine Seed Priming: A Way to Enhance Stress Tolerance in Plants

Polyamines (PAs), such as putrescine, spermine, and spermidine, are bioactive molecules that play a vital role in plant responses to stresses. Although they are frequently applied to achieve higher levels of stress tolerance in plants, their function in seed biology is still not fully understood. PAs have been described in only a limited number of studies as seed priming agents, but most of the data report only the physiological and biochemical PA effects, and only a few reports concern the molecular mechanisms. In this review, we summarized PA seed priming effects on germination, seedling establishment, and young plant response to abiotic stresses, and tried to draw a general scheme of PA action during early developmental plant stages.

Progress of ABA function in endosperm cellularization and storage product accumulation.

Seed development is a complex process and co-regulated by genetic and environmental factors, which significantly affects the seed vigor, yield and quality of crops, especially in cereal crops. Abscisic acid (ABA) regulates various biological processes in seed development, including endosperm and embryo development, accumulation of storage materials, achievement of desiccation tolerance and dormancy. Compared to the functional investigation of ABA in germination and stress response, the role of ABA in early seed development and storage product accumulation has not been collectively elucidated. Here, ABA origin in seed was concluded: both maternal source and de novo synthesis of ABA in seed play an important role in seed development. This review also provided an overview of the current knowledge on ABA in early seed development, mainly in endosperm cellularization. ABA promotes endosperm cellularization in Arabidopsis, but this notion has not been spread into cereal crops. Besides, the increasing importance of ABA in seed reserve accumulation was also emphatically described. In the last section, the key problems and challenges (e.g., where dose ABA come from at each stage of seed development? whether same regulators in response to ABA in Arabidopsis apply equally to cereal crops) were addressed.

Gibberellins treatment or stratification can break dormancy of the seeds of three Ranunculus species native to Korea

In this study, the seed germination and dormancy characteristics of three Ranunculus species native to Korea (R. cantoniensis, R. chinensis, and R. sceleratus) were determined to establish an effective dormancy-breaking protocol. The results revealed that the R. cantoniensis, R. chinensis, and R. sceleratus seeds responded differently to treatment with gibberellins (GAs) and stratification. Warm stratification at 20℃ increased the germination percentage and partially broke the dormancy of the R. cantoniensis seeds; moreover, the germination temperature range of the seeds expanded upon treatment with high-concentration GA4 + 7. Meanwhile, neither cold nor warm stratification was effective at breaking the dormancy of R. chinensis seeds; however, high-concentration GA4 + 7 treatment broke the dormancy of the seeds by expanding the germination temperature range. Lastly, the R. sceleratus seeds did not respond to the treatment with GAs; however, their germination percentage increased after undergoing warm stratification at 25℃. The seeds of these three species were characterized as exhibiting nondeep morphophysiological dormancy. The findings of this study enhance our understanding of the temperature-related germination responses of the three Ranunculus species, offering valuable insights into their conservation and utilization.

Warm temperature perceived at the vegetative stage affects progeny seed germination in natural accessions of Arabidopsis thaliana.

Temperatures perceived early in the life cycle of mother plants can affect the germination of the offspring seeds. In Arabidopsis thaliana, vernalisation-insensitive mutants showed altered germination response to elevated maternal temperature, hence revealing a strong genetic determinism. However, the genetic control of this maternal effect and its prevalence across natural populations remain unclear. Here, we exposed a collection of European accessions of A. thaliana to increased temperature during the vegetative phase and assessed germination in their progeny to identify the genetic basis of transgenerational germination response. We found that genotypes with rapidly germinating progeny after early maternal exposure to elevated temperature originated from regions with low-light radiation. Combining genome-wide association, expression analysis and functional assays across multiple genetic backgrounds, we show a central role for PHYB in mediating the response to maternally perceived temperature at the vegetative stage. Differential gene expression analysis in leaves identified a similar genetic network as previously found in seed endosperm under elevated temperature, supporting the pleiotropic involvement of PHYB signalling across different tissues and stages. This provides evidence that complex environmental responses modulated by the maternal genotype can rely on a consistent set of genes yet produce different effects at the different stages of exposure.

Unravelling the Significance of Seed Proteomics: Insights into Seed Development, Function, and Agricultural Applications.

Seeds are essential for plant reproduction, ensuring species survival and dispersal while adapting to diverse environments throughout a plant's life. Proteomics has emerged as a powerful tool for deciphering the complexities of seed growth, germination, and stress responses. Advanced proteomic technologies enable the analysis of protein changes during germination, dormancy, and ageing, enhancing our understanding of seed lifespan and vitality. Recent studies have revealed detailed insights into metabolic processes and storage protein profiles across various plant species. This knowledge is crucial for improving seed storage, conserving quality, and maintaining viability. Additionally, it contributes to sustainable agriculture by identifying stress-responsive proteins and signalling pathways that can mitigate stress and enhance farming practices. This review highlights significant advancements in seed proteomics over the past decade, discussing critical discoveries related to storage proteins, protein interactions, and proteome modifications due to stress. It illustrates how these insights transform seed biology, boosting productivity, food security, and environmentally friendly practices. The review also identifies existing knowledge gaps and provides direction for future research, underscoring the need for continued interdisciplinary collaboration in this dynamic field.

Multi-site Ultrasound-guided Fine Needle Aspiration to Study Cells and Soluble Factors From Human Lymph Nodes.

Lymph nodes (LNs) are specialized secondary lymphoid tissues essential to the priming and maintenance of adaptive immune responses, including the B cell germinal center response; thus, they are central to immunity. However, the anatomically restricted and time-resolved nature of immune priming means that sampling disease-relevant human LNs requires specialized techniques. This article describes the application of ultrasound-guided fine-needle aspiration (FNA) to sample LNs, using cervical LNs of the head and neck as an exemplar. This minimally invasive technique allows collection of both immune cells and cell-free material that are relevant to both neuroimmune diseases and basic lymphatic functions. Downstream use of cellular material can include multiplexed flow cytometry, single-cell transcriptome sequencing (RNA-seq), and B cell cultures. The cell-free supernatant can be used for proteomics or other similar 'omics approaches. This unit describes collection of samples by FNA as well as processing and storage of samples for downstream assays. © 2024 The Author(s). Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Sampling of human cervical lymph nodes by ultrasound-guided fine-needle aspiration Alternate Protocol: Sampling of human lymph nodes by ultrasound-guided fine-needle aspiration with negative pressure Basic Protocol 2: Processing and storage of human lymph node samples.

Macroclimatic Convergence and Habitat Specialisation Shape the Mediterranean Seed Germination Syndrome.

Ecological theory predicts that plant reproductive phenology in the Mediterranean regions is shaped by evolutionary processes driven by strong seasonality in precipitation-evaporation patterns. Thus, it can be expected that seed germination phenology has adapted to maximise recruitment during the season of highest water availability. Cold-cued and slow germination (i.e., the 'Mediterranean seed germination syndrome') has been hypothesised to be an adaptation to ensure that seedling emergence occurs in autumn/early winter, extending the growing season before the subsequent unfavourable summer drought. However, this hypothesis has been tested on individual species or local studies, without a proper synthesis for the whole Mediterranean region. Here we tested, for the first time, the Mediterranean seed germination syndrome using experimental data for 459 species (11,363 records, 59 families) occurring in the Mediterranean Basin. We performed a phylogenetically informed Bayesian meta-analysis to model the effect on germination proportions of seven key experimental cues: mean incubation temperature, alternating temperature regime, light and dormancy-breaking treatments (scarification, warm stratification and cold stratification) and the modulating role of seed mass on seed germination. We show that species from lowland zonal habitats of the Mediterranean align with the Mediterranean germination syndrome hypothesis, with their seeds responding positively to cool, constant temperatures and negatively to light. Yet, habitat specialists (i.e., species restricted to mountains, coasts and wetlands) deviate from the syndrome, showing nearly opposite germination requirements. Seed mass further influences the germination niche and phylogenetically related species exhibit similar germination responses. Cumulatively, these results suggest that evolutionary pressures from local habitat-related conditions override the macroclimatically imposed Mediterranean seed germination syndrome.

Molecular mechanism of flagellar motor rotation arrest in bacterial zoospores of Actinoplanes missouriensis before germination

Zoospores of the filamentous actinomycete Actinoplanes missouriensis swim vigorously using flagella and stop swimming to initiate germination in response to nutrient exposure. However, the molecular mechanisms underlying swimming cessation remain unknown. A protein (FtgA) of unknown function encoded by a chemotaxis gene cluster (che cluster-1) was found to be required for flagellar rotation arrest; the zoospores of ftgA-knockout mutants kept swimming awkwardly after germination. An ftgA-overexpressing strain exhibited a non-flagellated phenotype. Isolation of a suppressor strain from this strain and further in vivo experiments revealed that the extended N-terminal region of FliN, a component of the C-ring of the flagellar basal body, was involved in the function of FtgA; FliN-P101S canceled the flagellar rotation arrest by FtgA, as well as the negative effect of ftgA-overexpression on flagellation. Furthermore, bacterial two-hybrid assays suggested that FtgA interacted not only with the C-terminal core region of FliN but also with chemotaxis regulatory proteins CheA1 and CheW1-2, which are encoded by che cluster-1. We propose the following working model of motility regulation in A. missouriensis zoospores: the chemotaxis sensory complex initially captures FtgA to allow zoospores to swim and then releases FtgA to stop flagellar rotation (i.e., swimming) in response to external nutrient signals.

Seed ecology of the arid zone invasive thistle; Centaurea melitensis L.: A study of the effects of seasonal temperature, pH, salinity and moisture stress

AbstractCentaurea melitensis L., known commonly as Malta thistle, is an aggressive and invasive weed species native to the Mediterranean region. This species now occupies a diverse range of ecosystems and climate types across the globe, including the semi‐arid zone of New South Wales, Australia. This semi‐arid climate differs dramatically from its native Mediterranean climate, therefore, we aimed to identify if local adaptations in the seed ecology for C. melitensis have developed. Seeds were collected from mature C. melitensis at Nanya Station, located within the Scotia region of NSW, and then transported to Federation University Australia, Mt. Helen, Victoria. Under laboratory conditions, mature seeds were tested for their germination responses to temperature (17/7, 25/15, 30/20, 35/25°C), photoperiod (12 h light and 12 h dark [L/D], 24 h dark [D]), salinity (0, 25, 50, 100, 150, 200, and 250 mM), osmotic potential (0, −0.1, −0.2, −0.4, −0.6, and −0.8 MPa), and pH (5, 6, 6.2, 7, 8, 9, and 10). The seeds achieved 100% germination in the 17/7°C treatment, with light not being a limiting factor. The seeds exposed to the 25/15°C (D) and 30/20°C (D) treatments also maintained high germination percentage, whilst germination was significantly reduced in the 35/25°C (D) treatment. The L/D photoperiod maintained a 77.5% germination rate at 35/25°C. Whilst increased salinity reduced seed germination from 97.5% in the control to 6% at 250 mM, this species nevertheless demonstrated resistance to osmotic stress with 23% germination observed at 0.8 MPa. Germination exceeded 90% at all of the soil pH treatments, although mean germination time was significantly reduced when seeds were treated with a solution of pH 10. Our results demonstrate that the C. melitensis seeds collected in Australia's semi‐arid zone demonstrated high germination plasticity and are capable of competitive germination in warmer and drier conditions compared to its native Mediterranean climate. Therefore, management efforts that prioritise restricting the spread of C. melitensis seeds into new environments, for example through practising correct sanitation protocols, coupled with the early detection and control of emerging populations will be critical for C. melitensis management in Australia.

Where AIRE we now? Where AIRE we going?

The purpose of the review is to describe the most recent advancement in understanding of the pivotal role of autoimmune regulator ( AIRE ) gene expression in central and peripheral tolerance, and the implications of its impairment in the genetic and pathogenesis of autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) manifestations with insight into possible treatment options. AIRE gene expression has an important role of central and peripheral tolerance. Different AIRE gene mutations cause APECED, whereas polymorphisms and some variants may be implicated in development of other more frequently autoimmune diseases. Impaired negative T cell selection, reduction of T regulatory function, altered germinal center response, activated B cells and production of autoantibodies explain the development of autoimmunity in APECED. Recent data suggest that an excessive interferon-γ response may be the primer driver of the associated organ damage. Therefore, Janus kinase (JAK)-inhibitors may be promising therapies for treatment of broad spectrum of manifestations. AIRE has a pivotal role in immune tolerance. Disruption of this delicate equilibrium results in complex immune perturbation, ranging from severe autoimmunity, like APECED, to more common organ-specific disorders. Therefore, a deeper understanding of the correlation between AIRE function and clinical phenotype is warranted given the potential translational implication in clinical practice.

Biochemical Changes and Germination Response of Indian Sandalwood (Santalum album L.) Seeds Subjected to Biopriming Techniques and Variable Post-priming Storage

Understanding of the storage behaviour of endangered plant species such as Indian Sandalwood, Santalum album L. is important for successful conservation. We tested biopriming method with five biopriming agents (e.g. Effective microorganisms; Plant growth promoting rhizobacteria (PGPR-I and PGPR-II); Pseudomonas fluorescens and Piriformospora indica) with four uniform durations of treatments viz. 2, 4, 6 and 8 days. Hydropriming was also performed with similar condition for comparison of seed performance. The study examined the biochemical changes that occur in Sandalwood seeds during different post-priming storage periods (0, 30, 60, 90 days) to assess the efficacy of biopriming techniques on seed germination and health. Biopriming with Pseudomonas fluorescens for eight days recorded the highest germination percentage (70.67%) and the highest germination rate index (0.84). Longer durations of PGPR-I and Piriformospora indica treatment (6-8 days) lowered the imbibition period and mean germination time while increasing the germination rate. After a post-priming storage period of 30 days, only EM and Pseudomonas fluorescens treated seeds germinated while all other treatments failed to germinate. Absence of germination in any biopriming group at 60 and 90 days storage period indicated that the sandal seeds deteriorated over extended storage period. The reduction in seed viability of sandal seeds was consequent to the changes in the biochemical characteristics and action of enzymes (α and β amylases) involved in seed food reserve depletion and loss in membrane integrity.

Seed Germination Responses to Temperature and Osmotic Stress Conditions in Brachiaria Forage Grasses

Seed Germination Responses to Temperature and Osmotic Stress Conditions in Brachiaria Forage Grasses

Parental environment as a factor shaping salinity tolerance in halophyte Tripolium pannonicum L.

Parental environment can significantly influence a range of plant traits across different growth phases and developmental stages. The impact of parental salinity variability on offspring germination and environmental factor response still requires thorough investigation. Therefore, we investigated seeds of Tripolium pannonicum L. from low-saline (Cie) and high-saline (Ino) habitats to elucidate the germination potential and adaptation potential of progeny to varying salinity levels. Germination and growth experiments were conducted to analyze germination parameters, plant areas, water-related traits, the concentration of organic solutes, malondialdehyde, and the activity of crucial oxidative defence enzymes. In the germination experiment, Cie seeds demonstrated higher germination potential with longer germination time under 200–400 mM NaCl compare with Ino seeds. The Cie population achieved the highest shoot and roots area at 100 mM and 300 mM NaCl, respectively. The Ino population exhibited its highest shoot and roots area at 200 mM NaCl. The Ino population indicated an increase in stem cortex cell area at 400 mM NaCl. The Ino population enhanced the synthesis of osmolytes as part of the salinity tolerance mechanism. Antioxidant enzyme analysis indicated higher peroxidase activity in Ino and higher superoxide dismutase activity in Cie under salinity, suggesting distinct enzymatic roles in salinity adaptation between populations. Our findings highlight the critical role of parental environmental conditions in shaping progeny traits, enhancing germination potential, and enabling adaptation of progeny plants to diverse environmental niches. The study underscores population-specific responses to environmental factor, emphasizing the complexity of halophyte adaptation mechanisms to salinity.

Wheat TaTIFY3B and TaTIFY10A play roles in seed germination and abiotic stress responses in transgenic Arabidopsis and rice

BackgroundSeed germination is a key process in the plant life cycle that affects the vegetative and reproductive stages of plants. Although the JAZ gene family has been characterized in many plants, the relationship between the JAZ gene and seed germination is still unclear.ResultsWe identified two members of the JAZ family from wheat, TaTIFY3B and TaTIFY10A. TaTIFY3B and TaTIFY10A were localized in both the cell membrane and nucleus. Spatio-temporal expression analysis of TaTIFY3B and TaTIFY10A in wheat revealed that these genes are essential for the preharvest sprouting (PHS) stage of seed development, with expression levels significantly decreasing during the ripening period. Transgenic rice plants overexpressing wheat TaTIFY3B and TaTIFY10A improved seed germination rates. Transgenic Arabidopsis plants overexpressing wheat TaTIFY10A improved seed germination rates and promoted flowering. In addition, abscisic acid (ABA) and jasmonic acid (JA) were found to induce TaTIFY3B and TaTIFY10A expression. Under different ABA concentrations, the seed germination rates of transgenic rice and Arabidopsis overexpressing TaTIFY3B and TaTIFY10A are superior to wild-type (WT) and mutant plants, and the root lengths of Arabidopsis overexpressing TaTIFY3B and TaTIFY10A also change. Under different JA concentrations, there is no difference in the seed germination rate of rice overexpressing TaTIFY3B and TaTIFY10A compared to WT and mutant plants, but there is a significant difference in the seed germination rate and root length of overexpressing Arabidopsis compared to WT and mutant plants. Under different concentrations of salt and drought treatments, the seed germination rate and root length of overexpressing Arabidopsis of TaTIFY3B and TaTIFY10A are affected.ConclusionsThis study offers a novel perspective for understanding the molecular basis of pre-harvest sprouting and provides potential candidate genes for controlling wheat seed germination.

Relocalizing transcriptional kinases to activate apoptosis.

Kinases are critical regulators of cellular function that are commonly implicated in the mechanisms underlying disease. Most drugs that target kinases are molecules that inhibit their catalytic activity, but here we used chemically induced proximity to convert kinase inhibitors into activators of therapeutic genes. We synthesized bivalent molecules that link ligands of the transcription factor B cell lymphoma 6 (BCL6) to inhibitors of cyclin-dependent kinases (CDKs). These molecules relocalized CDK9 to BCL6-bound DNA and directed phosphorylation of RNA polymerase II. The resulting expression of pro-apoptotic, BCL6-target genes caused killing of diffuse large B cell lymphoma cells and specific ablation of the BCL6-regulated germinal center response. Genomics and proteomics corroborated a gain-of-function mechanism in which global kinase activity was not inhibited but rather redirected. Thus, kinase inhibitors can be used to context-specifically activate transcription.

Proline Priming Enhances Seed Vigour and Biochemical Attributes of Rice (Oryza sativa L.) during Germination.

Seed vigour is a desirable trait especially for direct seeded rice (DSR) cultivation. Seeds with high vigour could improve seed germination, support seedlings in competing with weeds for water and nutrients, and improving seedling establishment throughout the early stages of crop growth. The success of DSR system which account for more 25% of world cultivation areas is highly dependent on the seed vigour and seedling establishment. Seed priming is a promising technique to improve seed vigour. Proline is an amino acid that has been well studied for its roles in plants under different environmental stress conditions. Nevertheless, the effect of proline as a seed priming agent in improving seed vigour in rice remain elusive. In this research, the effect of 24 h of proline priming at various concentrations (0 mM, 1 mM, 2 mM, 10 mM and 20 mM) on rice seed vigour, amylase activity, and total soluble sugar (TSS) content of a Malaysia indica rice variety, MR269 was investigated. Results showed that seeds primed with lower concentration of proline (0 mM, 1 mM and 2 mM) had better germination responses while priming at high concentrations (10 mM and 20 mM) reduced seed germination. Among the concentration tested, priming with 1 mM proline enhanced seed vigour with significantly higher germination percentage (GP), germination rate index (GRI) and seedling vigour index (SVI). In addition, proline primed seeds also exhibited increased amylase activity and TSS content as compared to unprimed seeds. However, priming seed with 20 mM proline was detrimental to the seed vigour and seedling growth whereby lower GP, GRI and SVI and higher mean germination time (MGT) were observed. In short, this study shows that proline could be a potential seed priming agent to improve seed vigour in rice.

Advancing a Humanized Mouse Model to Study the Regulation of Germinal Center Response in Alloimmunity

Advancing a Humanized Mouse Model to Study the Regulation of Germinal Center Response in Alloimmunity