Search Results (2,632)

Membrane lipid remodeling plays a pivotal role in regulating plant growth, reproductive development, and adaptive responses to environmental stress. However, several lipid-modifying enzymes remain uncharacterized in Arabidopsis thaliana. Here, we provide the first comprehensive in silico functional characterization of the unannotated gene AT5G35460, integrating domain architecture, AlphaFold-supported structural validation, and phylogenetic, expression, and regulatory analyses. Domain architecture and conserved DUF2838 signatures, together with transmembrane topology and validation using AlphaFold-predicted structural data, support its identity as a glycerophosphocholine acyltransferase (GPCAT1). Phylogenetic reconstruction showed that GPCAT1 clustered closely with its orthologs of major angiosperms, suggesting deep evolutionary preservation. Expression profiling revealed over a tenfold higher transcript abundance in mature pollen, detected 6–8 times more than during leaf senescence, indicating strong developmental control. Co-expression network analysis revealed links to the lipid metabolism genes (CDS2, LACS8, and SBH1) as well as factors involved in response to stress, indicating that AT5G35460 may act at the level of phosphatidylcholine remodeling, membrane resistance and stress response. Analysis of the promoter sequences showed AACTAAA, ABRE and G-box elements (pollen-specific, ABA-responsive and stress-inducible motif respectively), suggesting appropriate transcriptional regulation consistent with its expression profile. As a whole, the findings revealed that AT5G35460 is an unexplored membrane-localized acyltransferase involved in lipid maintenance during reproductive development and environmental responses. This study serves as a basis for subsequent functional characterization and identifies AT5G35460 as a potential target for modifying pollen viability, senescence kinetics and stress tolerance in plants. Full article

There is an urgent need to find methods to reduce the discomfort caused by suspended pollutants in the atmosphere during pollen seasons with concurrent influenza circulation, which refers to a temporal overlap period (typically late spring in the temperate continental monsoon climate zone of northern China, such as Xi’an). During this type of season, the atmospheric environment undergoes specific changes in temperature, humidity, and air movement, which not only affect the survival, proliferation, and diffusion of planktonic microorganisms but also lead to the widespread suspension of pollen in the atmosphere. These factors collectively increase the complexity and harmfulness of atmospheric pollutants, posing a severe threat to human health, especially for vulnerable groups such as rhinitis patients. This study tested three types of commonly used fiber material masks to determine their filtration characteristics when filtering atmospheric particulate matter (PM₁₀, PM_2.5, and PM_1.0) and planktonic microorganisms, as well as their comfort. The results showed that N95 masks were the most effective, followed by surgical and sponge masks. Under different work intensities, the filtration efficiency of N95 masks were 16.32~23.38% and 35.93~37.91% higher than those of surgical and sponge masks for PM₁₀; 12.32~16.81% and 26.84~33.16% for PM_2.5; and 17.41~21.85% and 40.57~45.36% for PM_1.0, respectively. The largest difference in filtration efficiency was observed for 0–0.615 μm particles, which is mainly related to the mask’s material and protective effect, and is also closely associated with the physical and chemical properties of atmospheric particulate matter in this particle size range. N95 masks were able to filter planktonic microorganisms in the atmosphere, while sponge masks could not. Regarding the comfort level, the ranking was sponge masks > surgical masks > N95 masks. Therefore, based on comprehensive performance, it is recommended that patients with rhinitis and other conditions use N95 masks during pollen seasons with concurrent influenza circulation to effectively block harmful atmospheric pollutants. Individuals without rhinitis can choose surgical masks or sponge masks according to their comfort needs. This study provides data support for the rational use of fiber material masks in the context of atmospheric pollution during pollen seasons with concurrent influenza circulation and offers a reference for improving the performance of mask products in atmospheric pollutant filtration. Full article

This study presents a multiproxy paleoecological reconstruction from Laguna El Cacahuate, located ~180 km inland in the floodplain of Tabasco, southeastern Mexico, where red mangrove (Rhizophora mangle L.) forms persistent forest stands under freshwater conditions. We analyzed a 180 cm sediment core using pollen analysis, X-ray fluorescence geochemistry, and radiocarbon dating to investigate the environmental drivers of inland mangrove expansion. The core spans the last ~5200 years, capturing major shifts in vegetation and hydroperiod change. During the mid-Holocene, herbaceous freshwater taxa (Poaceae, Cyperaceae) dominated the floodplain under variable hydroclimatic conditions and high clastic input. The appearance of Rhizophora mangle pollen around 750 cal yr BP marks a significant ecological transition coinciding with geochemical indicators of stabilized flooding and reduced sedimentation. This inland colonization aligns temporally with increased regional precipitation and possible hydrogeomorphic changes following the 13th-century Plinian eruption of El Chichón. Unlike coastal mangroves, the persistence of Rhizophora under freshwater conditions supports the interpretation of this species as a facultative halophyte and indicates high resilience to long-term hydrological shifts. These findings provide critical insight into the ecological plasticity of mangroves, the paleoenvironmental history of the lower Usumacinta–San Pedro Basin, and the importance of integrating long-term records for wetland conservation strategies under future climate scenarios. Full article

Orchid pollination is traditionally considered to rely on intact pollinarium transfer by animal vectors. Species lacking a functional viscidium are generally classified as obligately autogamous. In this study, we investigated the reproductive biology of Epipactis bugacensis, a taxon long regarded as strictly self-pollinating. Floral visitor activity was assessed through repeated field observations, and pollinator dependence was tested using a pollinator-exclusion (net-covering) experiment at two Hungarian populations, combined with measurements of fruit set, capsule volume, seed number, and seed density. We documented a previously unreported pollen-transfer mechanism in E. bugacensis, whereby halictid bees fragment pollinia and transfer these fragments in their scopa to neighboring flowers enabling geitonogamous deposition and suggesting the potential for xenogamous pollen transfer. Other visitor taxa showed no evidence of effective pollen transport. Mesh coverage increased fruit set, capsule volume, and seed number, while seed density remained unchanged. Reproductive output declined from basal to apical positions along flowering shoots, revealing strong internal resource-allocation constraints. Overall, E. bugacensis is predominantly self-pollinating but not strictly obligate autogamous, and its reproductive success is governed primarily by microhabitat quality rather than pollinator availability. Full article

The generic delimitation of the two closely related Rosaceae genera, Eriobotrya and Rhaphiolepis, has not yet been investigated by a detailed study of their pollen morphology using scanning electron microscopy. To provide novel diagnostic features and insights into their relationships, we examined the pollen grains of thirty-one species of Eriobotrya and Rhaphiolepis, analyzing five quantitative and two qualitative morphological variables. The findings revealed that Eriobotrya and Rhaphiolepis pollen grains are tricolpate monads that are small to medium in size and vary in shape from prolate to perprolate, predominantly featuring striate ornamentation. Notably, striate-perforate and psilate exine sculptures were found only in Eriobotrya species, while scabrate ornamentation was unique to Rhaphiolepis. The rugulate pattern appeared in both genera. Eriobotrya (E. malipoensis K.C.Kuan) had the smallest pollen grains and the shortest distance between the apices of two ectocolpi, while Rhaphiolepis (R. integerrima Hook. & Arn.) had the largest. Multivariate cluster analysis separated all species from both genera into two distinct clusters. Cluster I contained all Eriobotrya species, whereas Cluster II included all Rhaphiolepis species, demonstrating their morphological distinctness and alignment with recent micro-morphological and molecular evidence. Furthermore, the pollen profile of E. seguinii Cardot ex Guillaumin affirms its taxonomic placement within Eriobotrya. We conclude that pollen morphology offers diagnostic information for delimiting these genera. The observed ornamentation pattern of a shared striate background, with distinct derived ornamentation in each genus, provides a clear morphological foundation for evolutionary investigations within the Maleae tribe. To further clarify generic boundaries and evolutionary processes, future research should integrate these palynological data with micromorphological analyses of other plant parts and genomic information. Full article

Poor nutrition is a known contributing factor to ongoing high rates of honey bee colony mortality. Beekeepers invest significant resources to provide supplemental feeds to their colonies, but currently available diets are nutritionally incomplete. To test whether commercially managed colonies fed a manufactured, nutritionally complete Pollen-Replacing Feed (PRF-1) would exhibit improved colony health outcomes compared to beekeeper-selected Commercial Standard Feeds, we tracked colony health metrics from fall through almond pollination and the subsequent spring in a large-scale, multi-year field trial. By January (in almonds), PRF-1-fed colonies had 1.19 more frames of bees (p < 0.001) and 18.7% more colonies meeting the 8-frame minimum size requirement for high-revenue pollination contracts. After almond pollination (March), PRF-1-fed colonies exhibited a 13.8% increase in survival (p = 0.002), 2.57 more frames of bees (p = 0.006), and 0.79 more frames of brood (p = 0.003). PRF-1-fed colonies also exhibited superior spring build-up, adding 1.22 more frames of bees between January and March (p = 0.03). Economically, a hypothetical 100-colony operation fed PRF-1 garnered an additional $12,065.81 in gross revenue in the first year. Nutritional benefits are projected to compound, leading to exponentially increased revenue over subsequent years. Persistent improvements in colony health demonstrate that providing a nutritionally complete pollen-replacing feed in fall and winter has a long-lasting, positive impact on colony health and commercial viability. Full article

This study examines the reproductive biology of five widely cultivated apple cultivars in Norway (‘Discovery’, ‘Rubinstep’, ‘Red Aroma’, ‘Elstar’, and ‘Asfari’), when crossed with the main pollenizers (‘Summerred’, ‘Discovery’, ‘Katja’, ‘Rubinstep’, ‘Red Aroma’, ‘Fryd’, and ‘Eden’, and two crab apples ‘Professor Sprenger’ and ‘Dolgo’), as well as under self-pollination and open pollination. The experiment was conducted over two seasons (2022–2023) in Hardanger, a region in Western Norway. Flowering time and overlap, in vitro pollen germination, pollen tube growth within the styles and ovary, embryo sac viability, fertilization success, and fruit set were analyzed as key reproductive parameters. Under broadly comparable climatic conditions across both seasons, the results showed that both mother cultivar and the pollenizer strongly influenced progamic processes and fruit set. Pollen tube growth through the pistil was generally faster and more successful in 2022 for all pollination combinations, resulting in a higher fruit set. The only exception was ‘Elstar’, which exhibited a higher fruit set in 2023. If a single optimal pollenizer were to be selected for each apple cultivar in Western Norway, it would be ‘Red Aroma’ for ‘Discovery’ and ‘Rubinstep’; ‘Rubinstep’ for ‘Red Aroma’ and ‘Elstar’; and ‘Professor Sprenger’ for ‘Asfari’. Based on pollen tube growth in vivo and the fruit set, cultivars ‘Discovery’, ‘Rubinstep’, ‘Red Aroma’, ‘Elstar’, and ‘Asfari’ showed self-incompatibility. Full article

Diabetes mellitus (DM) is a chronic metabolic disorder characterized by persistent systemic inflammation, which contributes to progressive multi-organ dysfunction, particularly in metabolically active tissues such as the liver and kidneys. Bee bread (Perga), a fermented bee pollen product rich in bioactive compounds, has been reported to exert anti-inflammatory and organ-protective effects; however, its tissue-specific influence on inflammatory responses under diabetic conditions remains incompletely defined. Thirty-two male Wistar Albino rats were randomly assigned to four groups: Control, DM, DM + Perga, and Perga. Diabetes was induced by streptozotocin (STZ; 55 mg/kg, i.p.). Perga was administered orally at a dose of 0.5 g/kg/day for 28 days. Pro-inflammatory cytokine levels (CRP, TNF-α, IL-1β, and IL-6) were quantified in liver and kidney tissues using ELISA. Histopathological alterations were evaluated by hematoxylin and eosin staining. DM significantly increased the IL-1β, IL-6, and CRP levels in hepatic tissue and elevated TNF-α, IL-1β, IL-6, and CRP levels in renal tissue. Perga administration attenuated these inflammatory responses, particularly reducing IL-1β and IL-6 levels in the liver and all measured cytokines in the kidney. Histopathological analyses revealed hepatocyte degeneration and necrosis, sinusoidal dilatation, tubular epithelial degeneration, and glomerular damage in diabetic rats, whereas Perga treatment partially improved hepatic alterations and improved renal structural integrity. These findings indicate that Perga exerts tissue-specific anti-inflammatory and protective effects in experimental diabetes, with a more pronounced impact on renal inflammation than on hepatic responses. Although its effects on hepatic TNF-α and CRP levels were limited, Perga may act as a natural modulator of cytokine-mediated inflammatory processes. Further studies are warranted to elucidate the underlying molecular mechanisms. Full article

Self-incompatibility (SI) is a key reproductive mechanism in angiosperms that prevents self-fertilization and promotes genetic diversity while limiting breeding efficiency. Akebia trifoliata is a recently domesticated economic crop native to East Asia with medicinal, edible, and oil-producing value. However, its late-acting self-incompatibility (LSI) severely limits genetic improvement and commercial development. To investigate the molecular basis of LSI, we conducted comparative transcriptomic analyses of pistils at 48, 96, 144, 192, and 240 h after self- and cross-pollination, identifying 1552, 2954, 1302, 814, and 1978 differentially expressed genes (DEGs), respectively. DEGs were consistently enriched in mitogen-activated protein kinase (MAPK) signaling, plant hormone signal transduction, and ubiquitin-mediated proteolysis pathways, with clear transcriptional differences before and after 96 h. Compared with cross-pollinated pistils, self-pollinated pistils showed restricted pollen tube spread, and genes related to pollen recognition and tube development showed differential expression at 48 and 96 h, indicating that LSI probably occurs within the pollen tube. Collectively, these results indicate that pistils of A. trifoliata exhibit distinct early responses to self- and cross-pollination, and that DEG-enriched pathways are similar to those involved in S-RNase-mediated SI. These results provide new insights into the molecular basis of LSI and suggest potential targets for overcoming the SI barrier. Full article

Non-specific lipid transfer proteins (nsLTPs) constitute a widely distributed family of plant allergens with substantial clinical relevance, particularly in food allergy. Their marked thermal and proteolytic stability enables them to provoke reactions ranging from mild local symptoms to severe anaphylaxis. This narrative review synthesises current knowledge on nsLTP allergens, focusing on their molecular characteristics, taxonomic distribution, exposure routes, and clinical impact. Major allergenic sources include fruits, nuts and seeds, vegetables and cereals, as well as various pollens. Across these sources, Pru p 3 has emerged as the central and most extensively studied allergen, frequently acting as the primary sensitiser and exhibiting broad cross-reactivity with homologous nsLTPs from diverse plant species. Despite growing evidence, significant knowledge gaps remain regarding sensitisation pathways, environmental modifiers, and phenotype stratification. Continued research is required to improve diagnostic precision and guide the development of targeted therapeutic strategies for patients with nsLTP-mediated allergy. Full article

In the process of maize production, extreme meteorological conditions such as drought and high temperature are often the main environmental stress factors affecting pollination efficiency. Previous studies have shown that, under adversity, the germination rate of pollen grains on the filaments of female spikes directly affects the success rate of reproduction and ultimately determines the grain yield. This study focuses on a cysteine protease named ZmPCP. The expression of this protease in maize pollen is significantly higher than in other tissues, and its specific function has not been clearly defined. Its localization in the cell membrane or apoplast was further confirmed by transient transfection experiments and plasmolysis. The interaction between ZmPCP and ZmSNAP33 was verified by yeast two-hybrid technology and a GST pull-down experiment, indicating that ZmPCP may affect pollen germination and stress resistance by regulating vesicle transport. Secondly, by analyzing the pollen germination rate of maize inbred lines B104, ZmPCP-KO and ZmPCP-OE transgenic maize plants, we found that ZmPCP overexpression could significantly enhance pollen viability and pollen tube growth under drought stress. After 1 h of short-term drying treatment, the pollen germination rate of the ZmPCP-OE line was maintained at 44%, which was significantly higher than that of the other lines. In addition, the observation of pollen tube growth showed that ZmPCP overexpression could promote the extension of pollen tubes in the filament. Moreover, a transcriptome sequencing analysis revealed the regulatory effects of ZmPCP on pollen in multiple biological processes, including stress response, carbohydrate metabolism, growth and development, cell wall material metabolism, signal transduction, etc. The involved pathways of these differential genes indicate that ZmPCP enhances pollen drought tolerance and promotes pollen tube growth through a “metabolism signal structure”. In the germination experiment on the seventh day, the germination rate of ZmPCP-OE maize seeds was the lowest, indicating that its overexpression inhibited seed germination. At the same time, ZmPCP-overexpressing Arabidopsis showed a significant advantage in taproot growth under high-concentration ABA stress. ZmPCP provides an important theoretical basis for regulating the pollination process and improving the pollination efficiency of maize varieties through interaction with ZmSNAP33. Full article

Honey bees (Apis mellifera L.) are considered highly significant economic insects. It is a source of valuable food and medicinal products such as honey, bee pollen, royal jelly, bee brood, and beeswax, which possess excellent nutritional and pharmacological properties. Nevertheless, honey bee health and productivity were often challenged by various environmental factors. Therefore, bee colony management is of the utmost importance. In this light, bee supplements and gut microbiota are crucial to ensure that bees receive sufficient nutritional value to maintain their health and productivity. In this study, we isolate and characterize lactic acid bacteria from the hindgut of the worker bee. 16S rRNA sequencing revealed that three isolated bacteria were Apilactobacillus kunkeei (AK), Lactiplantibacillus sp. (LP), and Lactobacillus brevis (LB). Three species of lactic acid bacteria were investigated for potential probiotic properties by supplementing 50% (w/w) sucrose syrup in the form of a direct-fed microorganism (DFM). The supplement with DFM had no negative effect on average lifespan. Examination took place of the impact of probiotics on the development of the hypopharyngeal glands (HPGs) in the bee’s head at days 3, 6, and 9 post-treatments. The cage-bees fed by pollen and DFM syrup exhibited acini surface areas ranging from 0.020 to 0.023 mm². The L. brevis (LB) group exhibited enhanced HPG development, with an average acini size of 0.027 ± 0.007 mm² at day 6, while the non-treatment control had an average acini size of 0.023 ± 0.006 mm². The significant size differences were maintained throughout the 9-day period. In addition, the DFM syrup enhanced microbial protein content in the bee head, digestibility, and community complexity compared with the negative control groups. Therefore, the DFM syrup with a potential strain of probiotic may enhance overall honey bee health status. Full article

The pseudoacacia species (Robinia pseudoacacia L.) are flowering plants that produce nectar and can be the sources of unifloral honey. Robinia is native to North America and is invasive in several European countries. The aim of this work was to determine and compare the physicochemical parameters, proline content, and antioxidant capacity of pseudoacacia honey collected from different locations in two central European countries (Hungary and Slovakia). The botanical origin of each honey sample was verified by melissopalynological analysis. The color intensity was determined using the Pfund scale. The antioxidant activity was determined with different spectrophotometric methods (DPPH, ABTS, and FRAP). The content of the total polyphenols, flavonoids, phenolic acids, and proline was quantified using spectrophotometric methods. The electrical conductivity, refractive index, and optical rotation were analyzed according to European Pharmacopoeia, 12th edition. Our study shows that the antioxidant capacity, and proline and phenolic content of unifloral pseudoacacia honeys can vary according to the geographical origin, polyphenol content, and the pollen profile in honey samples. Full article

In this paper, we present the results of a paleoanthracological analysis of the Lateglacial Kulikovo section (eastern Baltic, Kaliningrad region). This is proposed as a new methodological approach to studying the presence of woody taxa in Lateglacial vegetation. Woody vegetation is an important marker of environmental dynamics in post-glacial areas and one of the most important indicators of climate amelioration. Therefore, establishing the time of the appearance of woody vegetation during the Lateglacial period is essential. Paleoanthracological analysis revealed 22 macrocharcoal morphotypes, among which were the following indicators of woody (coniferous and deciduous) vegetation: wood, punky wood, needles, leaf stems, etc. The results indicate an almost continuous local presence of woody species in the study area since the Older Dryas, 14.0 ka. This conclusion is in good agreement with the available data on the presence of phytoliths of conifers and palynological data, indicating that from the end of the Older Dryas up to approximately 12.5 ka, the percentage of arboreal vegetation did not fall below 50% of terrestrial pollen, and over a significant part of the studied time interval it reached 70–80%. Paleoanthracological analysis can serve as both an independent method of studying the emergence of woody vegetation in a certain area and an important addition to the reconstruction of Lateglacial vegetation based on pollen data. Full article

Bee pollen is a nutrient-dense food; however, its dense cell wall limits the bioavailability and digestive absorption of nutrients. This study established a co-fermentation process that combines Lactobacillus strains isolated from bee bread with commercial probiotics to improve the nutritional profile and functional properties of bee pollen. L. acidophilus (LBA1) and L. plantarum (LBP3) were isolated from bee bread and used for single-strain fermentation of bee pollen and its co-fermentation with commercial probiotics. The results indicated that fermentation increased the protein, free amino acid, vitamin C, and flavonoid contents. The co-fermentation product (FHL-99) of LBP3 and the commercial inoculant (99 strains) exhibited the highest cell wall disruption rate (67.57%) in artificial intestinal juice. Ex vivo activity analysis revealed enhanced DPPH, hydroxyl, and ABTS⁺ radical scavenging capacities of fermented bee pollen. Its inhibitory effects on hyaluronidase activity and protein thermal denaturation were also enhanced. FHL-99 demonstrated optimal performance across multiple indices, achieving a DPPH radical scavenging rate of 77.46% and hyaluronidase inhibition rate of 37.38%. In conclusion, synergistic co-fermentation can disrupt pollen cell walls and enrich bioactive constituents, providing an efficient biotechnological approach for the development of high-quality fermented bee pollen products. Full article