Search Results (386)

Alzheimer’s disease (AD) is characterized by progressive cognitive decline and the accumulation of amyloid-β (Aβ) plaques and tau neurofibrillary tangles. Beyond genetic and proteostatic mechanisms, infection- and dysbiosis-based models of AD have gained renewed attention, including the antimicrobial protection hypothesis, in which Aβ may participate in innate immune defense. Here, we reanalyzed ribosomal depleted (Ribo-Zero) RNA-seq data from dorsolateral prefrontal cortex (DLPFC) samples from the Mount Sinai Brain Bank cohort (GSE53697) to screen for non-human transcripts. Reads underwent quality control and adapter trimming, taxonomic classification with Kraken2, abundance re-estimation with Bracken, and differential abundance testing with edgeR. Across 17 samples (9 advanced AD and 8 controls), we detected low-biomass microbial signals, with Acinetobacter radioresistens showing enrichment in the AD group (FDR = 0.018). Several additional taxa showed suggestive group differences but did not remain significant after multiple testing correction, including Lactobacillus iners (FDR = 0.051). We also performed an exploratory in silico analysis of an A. radioresistens biofilm-associated protein homolog, identifying predicted amyloidogenic motifs and surface-exposed regions that may be relevant to cross-seeding hypotheses, although no mechanistic inference can be drawn without experimental validation. Given the technical challenges of inferring microbial signals from post-mortem brain RNA-seq data, including contamination risk, low microbial biomass, and overwhelming host background, these findings should be interpreted as hypothesis-generating and warrant orthogonal validation in larger, microbiome-aware cohorts. Full article

Extreme droughts are projected to become more frequent and severe under climate change, posing significant risks to wetland ecosystems and submerged macrophyte communities. We combined field surveys in West Dongting Lake, China, combined with controlled greenhouse experiments to examine how drought intensity (expressed as contrasting soil moisture conditions during drought) and drought timing affect submerged macrophyte species richness, biomass, as well as resilience, mediated through species response in their reproductive strategies. Field observations revealed a sharp decline in clonal species (Hydrilla verticillata, Ceratophyllum demersum, Vallisneria spinulosa) following an extreme drought, while the sexual species Najas marina emerged as dominant. Greenhouse experiments confirmed these patterns and elucidated underlying mechanisms: extreme drought suppressed biomass, leaf area, and seedling re-germination in clonal species, whereas N. marina maintained regeneration via a persistent soil seed bank. Moderate drought enhanced leaf area, consistent with the intermediate disturbance hypothesis, while early drawdowns were most detrimental to growth. Species-specific responses highlight the role of reproductive strategy in drought resilience. These findings underscore the need for climate-adaptive water-level management, including limiting early drawdowns, mitigating extreme drought, and conserving seed banks to sustain biodiversity and ecosystem function under increasing hydroclimatic variability. Full article

Vegetation in desert ecosystems is strongly affected by seasonal climatic fluctuations and soil physical and chemical properties. Rawdat Nourah is a natural watershed depression within the King Abdulaziz Royal Reserve in Saudi Arabia. It is colonized by grasses, herbs, and shrubs. Climatic variability and soil heterogeneity are influencing the vegetation dynamics and regeneration patterns in this ecosystem. Based on the literature review, no previous study analyzed and determined either the vegetation composition or the soil seed-bank of Rawdat Nourah. So, the general objective of this study is to examine the vegetation composition and its relationships with soil physicochemical properties and soil seed-bank composition across Rawdat Nourah across different seasons. Floristic analyses, vegetation composition, soil properties, and soil seed-bank were performed within two seasons (winter–spring and summer–fall seasons) of 2023–2024. The obtained data were analyzed using multivariate and statistical approaches. Six plant associations were identified: winter–spring (WVG I: Zilla spinosa–Malva parviflora; WVG II: Rhazya stricta–Zilla spinosa; WVG III: Cynodon dactylon–Convolvulus pilosellifolius) and summer–fall (SVG I: Calotropis procera–Pulicaria undulata; SVG II: Cynodon dactylon–Zilla spinosa; SVG III: Rhazya stricta–Schismus arabicus). Species richness was higher in winter–spring (2.4 species stand⁻¹) than in summer–fall (1.66 species stand⁻¹), while the seed-bank densities were 633.9 and 575.1 seeds m⁻², respectively. Vegetation responded strongly to marked seasonal contrasts in temperature and moisture (~15 °C, 11 mm vs. ~36 °C, 3 mm). Moderate human activity enhanced vegetation cover, whereas prolonged grazing exclusion reduced diversity through the dominance of a few species. The response of vegetation structure and species richness to climatic factors varies greatly depending on the increase in water availability, and moisture content during the mild weather Winter–Spring season (mean temperature is 15 °C and rainfall is 11 mm), compared to the Summer–Autumn season (mean temperature is 36 °C and rainfall is 3 mm). The richness and cover of the plants were generally affected by human activity, where long-term grazing will reduce species richness and increase competition between species, making one or two species dominant. Although above-ground vegetation exhibited clear seasonal and spatial shifts in species composition and abundance, these changes were not reflected in the soil seed-bank. This relation suggests that above-ground communities and seed-banks are regulated by different ecological processes under arid conditions. The data of the present study showed low correlation between the current vegetation and the soil seed bank, which reflects a degradation in this region. Therefore, these findings suggest that sustained protection of the King Abdulaziz Royal Reserve is essential for enhancing seed-bank persistence, vegetation recovery, and ecosystem resilience under arid conditions. Full article

Introduction: Bacteriophages are emerging as viable food safety tools, yet their global implementation is hindered by regulatory fragmentation and a lack of harmonized data standards. This review addresses the gap between scientific maturity and governance readiness by evaluating manufacturing quality, safety requirements, and international oversight frameworks. Methods: A narrative review was conducted through a structured search of databases including PubMed, Scopus, Web of Science, and Google Scholar (up to December 2025). We analyzed scientific research and publicly available regulatory documents from agencies such as the FDA, EFSA, USDA, Health Canada, and FSANZ to identify authorization routes and manufacturing standards. Results: Commercial phage products are primarily approved as processing aids in jurisdictions like the United States, Canada, and Australia/New Zealand. We identified convergent technical requirements across these regions, including genomic integrity (absence of toxins and antimicrobial resistance genes), purity, potency, and matrix-validated efficacy. However, significant gaps remain in unified terminology, environmental risk assessment, and post-market monitoring for resistance emergence. Conclusions: To facilitate global adoption, a One Health-oriented governance cycle is proposed. This includes establishing interoperable phage seed banks, standardized dossier formats, and adaptive lifecycle controls (phagovigilance) to ensure long-term efficacy and public trust. Full article

Microplastic contamination has emerged as a growing concern for soil ecosystems and their ecological functioning. However, the effects of microplastic contamination in fragile plateau wetlands remain poorly understood. In this study, biodegradable polylactic acid (PLA) and conventional polypropylene (PP) MPs were compared using soil seed bank collected from terrestrial and hygrophytic habitats in the Xingyun Lake plateau wetland. Seed germination, species diversity, and soil chemical properties were evaluated. Habitat specific effects were observed, and PLA induced stronger inhibition of seed germination and diversity than PP. These findings underscore the need to incorporate plant ecological responses, including germination physiology under chemical stress and soil seed bank dynamics, into ecological risk assessments of MPs. Furthermore, MP associated changes in nutrient dynamics and soil chemistry were examined, providing insight into potential long-term implications for plateau wetland restoration and plant community recovery. Full article

Access to quality seed is a critical driver of smallholder productivity and household food security in South Africa, yet rural communities in the Eastern Cape continue to rely heavily on informal seed systems. Limited seed literacy among farmers and vendors is widely recognized as a constraint to the effective selection and use of high-quality seed. The purpose of this study is to assess seed literacy levels among smallholder farmers in KwaMkhiva village and evaluate how knowledge gaps shape farmers’ seed sourcing patterns and access to quality seed. The study hypothesizes that low seed literacy significantly increases reliance on informal seed systems and reduces adoption of certified or improved varieties. A quantitative, cross-sectional survey design was used to collect data from 50 smallholder farmers and 12 informal seedling vendors, complemented by semi-structured interviews with three extension officers. Descriptive statistics, chi-square tests, correlation analysis, and a composite Seed Literacy Index (SLI) were employed to assess literacy dimensions and their association with seed choices. Findings show that 49% of farmers rely on local markets and 40% use farm-saved seed, with 75% assessing quality visually rather than through germination or varietal indicators. Only 10% had received any seed-related training, and awareness of seed adaptability and crop rotation was below 20%. Higher SLI scores were positively associated with adoption of certified seed (r = 0.42, p < 0.01) and crop diversification. The study concludes that seed literacy is a critical yet underserved capability that shapes smallholder seed access within dual seed economies. Strengthening farmer-centred seed literacy programmes, revitalising extension services, and supporting community seed banks could enhance access to quality seed and improve smallholder resilience. Full article

Genes important for research and breeding plant varieties are crucial for the survival and development of human civilization. Seeds of cereal germplasm are maintained in gene banks (GBs) and grain viability of GB accessions must be regularly restored by seed multiplication. During related operations human errors may lead to contaminated or mislabeled accessions and resultant genotype non-authenticity. Such mistakes accumulate over time. In this report, 1412 lines derived from 289 accessions of 93 barley varieties, each obtained from several GBs, were analyzed. Five single seed progenies (SSPs) were usually harvested from an accession and their major genes conferring powdery mildew resistance were postulated. Twenty-two known resistance genes and 60 of their combinations were identified. Non-authentic genotypes contained different genes compared with genes present in other genotypes of the same variety. Based on these results we found at least 40 (13.8%) mislabeled and 102 (35.3%) heterogeneous accessions in which 276 lines (19.7%) carried non-authentic genotypes. Misrepresented varieties in GBs are a great problem for research projects, especially those focused on finding new (e.g., molecular) varietal characteristics, and in breeding programs as the required gene combination cannot be obtained. Full article

Drought is regarded as the most significant environmental factor affecting the productivity of maize (Zea mays L.) worldwide. The integration of maize landraces, conserved in germplasm bank collections, into elite breeding programs could increase the resilience of modern hybrids to drought and mitigate the genetic erosion identified within the genetic base of cultivated maize. In this study, seeds of fifteen Croatian maize landraces were exposed to four levels of drought stress induced by polyethylene glycol (PEG) to evaluate the effect of drought on their seed germination and seedling root parameters. Analysis of variance revealed significant differences among landraces (G) and applied drought stress treatments (PEG) for all traits, as well as a significant PEG × G interaction for all traits except germination potential. The application of the highest drought stress level, caused by a 20% PEG water solution, reduced germination percentage by 51%, germination potential by 99%, root length by 87%, root diameter by 26%, root area by 91% and root volume by 93% compared to the control. Three landraces, MAK7, MAK11 and MAK15, showing high germination potential, long roots and large root area and volume under drought conditions, were identified as pre-breeding candidates for possible reintroduction into modern breeding programs aimed at increasing drought tolerance. The applied method of PEG-induced drought effectively identified drought-tolerant landraces and can be used for rapid screening of drought tolerance in large numbers of genebank accessions conserved in genebanks. Full article

Passiflora germplasm represents an important genetic resource for improving fruit yield and quality in breeding programs targeting semi-arid environments. This study aimed to assess the phenotypic diversity, genetic parameters, and breeding potential of Passiflora accessions conserved in the Passion Fruit Active Germplasm Bank of Embrapa Semiárido. A total of 55 accessions, predominantly Passiflora cincinnata Mast., were evaluated using morphoagronomic descriptors related to plant, flower, and fruit traits. Quantitative data were analyzed using mixed linear models (REML/BLUP) to estimate genetic parameters, and multivariate analyses were applied to characterize phenotypic divergence. Substantial phenotypic variability was observed, particularly for fruit-related traits. Fruit weight ranged from 43.25 to 142.88 g, pulp weight ranged from 7.86 to 51.37 g, and pulp yield ranged from 17.06% to 40.27% among accessions. Broad-sense heritability estimates for key fruit traits were moderate to high, reaching 0.50 for fruit weight, 0.49 for pulp weight, and 0.36 for pulp yield, indicating favorable prospects for selection. Principal Component Analysis explained 66.0% of the total variation in the first two components, with fruit size, pulp-related traits, and seed number contributing most strongly to accession differentiation. Multivariate analyses consistently identified accessions 1 and 16 as superior for fruit weight and pulp yield, whereas accession 55 combined high fruit weight with elevated soluble solid content (up to 14.24 °Brix) but lower pulp yield. Overall, the observed variability highlights the relevance of Passiflora germplasm conserved under semi-arid conditions as a valuable resource for breeding programs focused on fruit yield, quality, and adaptation to water-limited environments. Full article

For the development of effective and secure methods for plant genetic resources preservation, different storage treatments of fiber flax seeds were compared. Seeds of the flax variety Orshanskiy-2 in aluminum foil bags were stored at different low temperatures, including in liquid nitrogen. Agronomic characters of plants grown from them and next-generation seeds were compared. Plants grown from frozen seeds changed 14 out of 31 evaluated characters in comparison with the non-frozen control. The biggest changes were detected after gradual freezing in liquid nitrogen, due to mechanical damage of the seed coat, and storage at −10 °C for 24 years. Freezing had a negative effect on production characters (straw, fiber and seed) because of the reduction of the germinated plant number. Seeds stored for 24 years at −10 °C, compared to control plants, ripened earlier, grew higher, produced a greater yield of straw and fiber, but had reduced fiber quality and increased seed size. Plants of the next generation showed a tendency toward attenuation of the storage time influence on flax characters. However, it is unknown how many years this process will take. For seed preservation in GeneBanks, it is recommended to use several variants of storage conditions and use rapid cooling and/or cryoprotectors. The latter two methods, which have been successfully used for other crops, should be implemented only after preliminary experiments. Full article

Outside their native habitat, goldenrods (Solidago spp.) threaten ecosystem biodiversity through aggressive vegetative reproduction and by establishing dense stands. Climate-driven fire risks and illegal grassland burning increase exposure to smoke-derived compounds such as karrikins (KARs), which are known to regulate germination and development in many species but have never been studied in goldenrods. Understanding KARs’ effects on seeds and rhizomes is essential for predicting invasion dynamics and designing effective management strategies. This study aimed to determine whether karrikin 1 (KAR1) influences seed germination and rhizome bud development in Solidago gigantea, thereby affecting its invasiveness and offering a potential method of control. Two geographically isolated populations were analyzed using seeds, soil, above-ground plant biomass and rhizomes. Germination tests evaluated whether KAR mimics light and gibberellic acid (GA), a known germination stimulant. Greenhouse trials assessed rhizome response, while field experiments monitored whole-plant performance over two years. KAR stimulated seed germination comparably to light and GA and promoted seedling emergence from the seed bank, but it inhibited rhizome sprouting by about 15%. It also enhanced the emergence of other species, suggesting broad physiological activity and the potential to influence early-season plant community dynamics. These findings highlight KAR’s potential as a management tool for invasive goldenrod and provide new insights into smoke-derived compounds as ecological regulators. Full article

California sage scrub is an endangered, shrub-dominated, southern California ecosystem threatened by increasing fire frequencies and type-conversion to non-native grasslands. Once non-native grasses become established, their presence promotes more frequent fires, perpetuating grass dominance. To better understand how fire influences soil seed bank assemblages, we examined soil seed banks in burned and adjacent unburned sage scrub at the Robert J. Bernard Field Station (BFS) in two areas that burned in September 2013 and May 2017. In contrast to a previous soil seed bank study in California sage scrub, we found that unburned soil seed banks in sage scrub at the BFS were primarily composed of native seeds (88% of sprouts in unburned areas were native), highlighting that soil seed bank dynamics differ among California sage scrub sites. Despite burned areas supporting elevated densities of non-native seeds (the majority of which included Festuca myuros, a non-native grass), soil seed banks in our burned areas retained native seeds (21% of sprouts in burned areas were native), including native shrub species, suggesting that not all sage scrub habitats are primed to transition to non-native grasslands following disturbances. However, elevated densities on non-native seedlings in burned areas highlight the vulnerability of sage scrub to fire disturbances and the subsequent establishment of non-native grasses. Full article

Protists represent a vast yet underexplored reservoir of enzymatic diversity across the eukaryotic tree of life. In this study, we established axenic strains of diverse protists from four major eukaryotic supergroups using single-cell isolation and generated de novo transcriptomes for each strain, as reference genomes or transcriptomes are not available for these strains. As a test case for industrial enzyme discovery, we targeted nine enzyme classes used in pulp processing and evaluated whether protist-derived sequences occupy underrepresented sequence space relative to major public databases. Functional annotation combined with Sequence Similarity Network analysis revealed multiple clusters composed exclusively of protist-origin sequences, indicating candidate enzymes with high sequence-level novelty. These results suggest that protists may provide a practical resource for expanding the repertoire of industrially relevant enzymes and prioritizing targets for further characterization. However, additional in silico analyses and experimental validation will be required to determine whether these sequence-divergent candidates exhibit properties that meet industrial requirements. Full article

Climate change is altering temperature and precipitation regimes in Argentina, with potential consequences for regeneration and persistence of forest tree species, emphasizing the importance of ex situ seed conservation. We evaluated interannual variation in seed traits, desiccation tolerance, storage behavior, and longevity of Cedrela balansae C. DC. and C. fissilis Vell. (Meliaceae), two endangered native species of subtropical rainforests in Argentina. Both species produced desiccation-tolerant seeds, independently of collection year, seed traits, or climatic conditions. Depending on the species, seed traits and longevity varied across years and showed strong relationships with temperature and precipitation, particularly during seed development. Cedrela balansae seeds are medium-lived seeds and have high longevity under standard seed banking conditions, suggesting strong potential for long-term ex situ conservation. Cedrela fissilis seeds are short-lived seeds and have high sensitivity to the storage environment. Correlations among climatic variables and seed traits and longevity parameters suggest that future warming and drying environments may shorten the window for germination and seedling establishment, with species-specific responses depending on climatic conditions during seed development. These results highlight the importance of climate effects in determining seed traits and seed longevity and emphasize the role of seed banking as a critical conservation strategy under climate change. Full article

Invasive alien plants (IAPs) disrupt biodiversity, ecosystem functions, rural livelihoods, and human health/well-being. Hence, the negative impact of Cenchrus setaceus (syn. Pennisetum setaceum) as an invasive weed poses many concerns in terms of environmental and socio-economic impact. The abundance in previous research on invasion ecology, weed biology, and the management of C. setaceus establishes the chance to carry out an in-depth evaluation of this invasive alien species for a cohesive understanding, closely linked to policy development. This systematic review aims to provide a comprehensive evaluation of previous research, identify knowledge gaps, and incorporate recent practical research findings on C. setaceus to elucidate management options. Standard methods were used to collect the literary evidence on multiple thematic aspects linked with its traits and management. Results revealed the substantial negative impacts of C. setaceus on ecosystems, ascribed to multiple physiological, biochemical, and ecological features. Further, a multitude of plant traits such as rapid seed distribution and efficient reproductive strategies imposed serious challenges in the control of C. setaceus. Deployment of integrated control methods for at least three years in depleting seed bank conjunction by planting native grass may help in its confinement. In conclusion, policy measures like strict biosecurity/legal regulations, explicit elucidation of weed biology, early detection and response, ecological modeling, and long-term monitoring with community participation can expand the horizon of C. setaceus control and help achieve its sustainable management. Full article