Search Results (38)

Transgenic tobacco plants with additional enzymes producing hydrogen peroxide (H₂O₂)—superoxide dismutase from Arabisopsis thaliana and choline oxidase from Arthrobacter globiformis—have increased resistance to stress factors, which was demonstrated previously, but their reproductive potential has not been studied to date. Superoxide dismutase converts superoxide radical into H₂O₂, and choline oxidase catalyzes the oxidation reaction of choline to form betaine aldehyde, which is subsequently converted into glycine betaine and H₂O₂. We found that the addition of both exogenous genes stimulated growth of the floral organs: petals, styles, and stamens. However, the reproductive potential of the transgenic plants was different. Thus, the introduction of the superoxide dismutase gene FeSOD significantly increased pollen germination in vitro, in vivo, the size of fruits, and the number of seeds. At the same time, the insertion of the CodA gene resulted in the production of abnormal pollen with low germination in vitro. The female reproductive potential system in these plants was not affected. Thus, shifting the ROS balance towards hydrogen peroxide not only increases tobacco stress resistance but also stimulates reproductive success. Glycine betaine production disrupts pollen formation, although such plants show increased resistance to osmotic stress. Full article

Plastic pollution has become a critical environmental issue, with vast amounts of plastic waste accumulating in aquatic and terrestrial ecosystems. Plastic pollution poses significant risks to biodiversity by introducing toxic chemicals and disrupting biological functions. The drone fly, Eristalis tenax, is perhaps the most globally widespread hoverfly. This success is aided by its development as a rat-tailed maggot in a wide array of aquatic environments where it feeds on decaying organic matter. As an adult, E. tenax is a vital pollinator, visiting a wide range of crops and wild plants, and has been shown to vector pollen over hundreds of kilometres during seasonal migrations. Exposure to microplastics during larval stages has the potential to alter the provision of these ecosystem services and to provide a route for the long-distance vectoring of microplastics. To investigate this, we rear E. tenax in water contaminated with different concentrations of microplastic particles. We show that these plastics are retained in the gut from larval through to pupal to adult developmental stages. This contamination resulted in reductions of 33% and 60% in pupal and adult weight when exposed to the highest concentrations of microplastic particles but resulted in no detectable effects on mortality or developmental length. Our results demonstrate the potential for the vectoring of microplastics by this highly mobile species. However, the associated reductions in body size likely have profound consequences for movement capability in terms of foraging and migration and should be further investigated for their impact on ecosystem service provision. Full article

(1) Background: Respiratory allergens, particularly ragweed (RW) pollen and house dust mites (HDMs), are major triggers of respiratory inflammation and allergic diseases. This study investigated the impact of single- versus combined-allergen exposure on the barrier function of normal human bronchial epithelial (NHBE) cells cultured at the air–liquid interface (ALI). (2) Methods: NHBE cells were exposed to RW pollen extract (200 µg/mL), HDM extract (200 µg/mL) and their combination at varying concentrations (200 µg/mL, 100 µg/mL, 50 µg/mL, 25 µg/mL). Additional groups included a mixture of Amb a 1, Amb a 11 and Amb a 12 (100 mg/mL) and combinations of Der p 1 with the ragweed allergens (50 mg/mL, 100 µg/mL). Transepithelial electrical resistance (TEER) was recorded over 72 hours to assess barrier integrity, and immunofluorescence (IF) staining for zonula occludens-1 (ZO-1) was performed to evaluate tight junction alterations. (3) Results: TEER measurements showed a significant reduction in epithelial barrier integrity following allergen exposure, with the most pronounced disruption observed with the combined exposure to RW and HDM groups. IF staining confirmed extensive tight junction damage, highlighting their synergistic impact. (4) Conclusions: These findings emphasize the importance of assessing cumulative allergen effects, as combined exposure may exacerbate epithelial dysfunction and represent a key aspect in the management of allergic rhinitis and asthma. Full article

To clarify the pollination contributions of introduced honey bees and native wild bees, we compared their pollination efficiency on a perennial herb, Polygonatum cyrtonema Hua. The flower’s traits and bees’ body traits were measured to quantify the mechanical fit between the bee species and flower. Pollen removal and deposition per visit, visit frequency, and visit duration per flower were investigated. The results show that both native bumble bees (worker bees of Bombus trifasciatus Smith) and introduced honey bees (Apis mellifera L.) are effective pollinators, but bumble bees play a more important role in pollination, due to their higher visit frequency and slightly higher pollen transfer efficiency. The bumble bees removed and deposited significantly more pollen grains per visit than the honey bees (both p < 0.001). The faster visiting speed and shorter visit duration of the bumble bees, combined with their larger body size and longer proboscises, may have contributed to their higher pollen transfer efficiency. The pollination success of P. cyrtonema depends on its pollinators. This study is the first to report on the pollination efficiency of floral visitors on P. cyrtonema. Our findings highlight the importance of conserving native bumble bee populations to ensure the reproductive success of P. cyrtonema. Future studies should focus on their management to minimize potential disruptions to native pollination contribution. Full article

Hive products, encompassing honey, propolis, bee venom, royal jelly, and pollen, are recognized for their antimicrobial and therapeutic properties. This review examines their chemical composition, explores their mechanisms of action, and discusses their potential applications in both human and veterinary medicine, particularly in addressing the challenge of antimicrobial resistance. This study utilized a comprehensive literature search strategy, gathering data from Google Scholar, MEDLINE PubMed, SciELO, and SCOPUS databases. Relevant search terms were employed to ensure a thorough retrieval of the pertinent literature. Honey, rich in bioactive compounds such as hydrogen peroxide and methylglyoxal, effectively disrupts biofilms and combats multi-drug-resistant pathogens, showing promise in treating a range of infections. Propolis, with its flavonoids and phenolic acids, demonstrates synergistic effects when used in conjunction with antibiotics. Bee venom, particularly its component melittin, exhibits antibacterial and immunomodulatory properties, although further research is needed to address toxicity concerns. Pollen and royal jelly demonstrate broad-spectrum antimicrobial activity, which is particularly relevant to animal health. Existing pre-clinical and clinical data support the therapeutic potential of these hive products. Hive products represent a vast and largely untapped natural resource for combating antimicrobial resistance and developing sustainable therapies, particularly in the field of veterinary medicine. However, challenges remain due to the inherent variability in their composition and the lack of standardized protocols for their preparation and application. Further research is essential to fully elucidate their mechanisms of action, optimize formulations for enhanced efficacy, and establish standardized protocols to ensure their safe and effective clinical use. Full article

Adenosine monophosphate (AMP) is a hydrolysis product of adenosine triphosphate (ATP) and adenosine diphosphate (ADP). In mammalian cells, extracellular AMP functions as a signaling molecule by binding to adenosine A1 receptors, thereby activating various intracellular signaling pathways. However, the role of extracellular AMP in plant cells remains largely unclear, and homologs of A1 receptors have not been identified. Our previous studies have demonstrated that extracellular ATP (eATP) is crucial for the normal germination and growth of Picea meyeri pollen tubes. In the present study, we observed that the exogenous addition of ATP to a pollen culture medium could be degraded into AMP and adenosine. Furthermore, the addition of AMP and adenosine to the culture medium was found to inhibit pollen germination and tube elongation. Notably, the addition of an AMP receptor inhibitor into the culture medium mitigated the inhibitory effects of AMP on pollen tube growth. Through intracellular staining for Ca²⁺ and microfilaments, we discovered that high concentrations of AMP disrupt the Ca²⁺ concentration gradient and impair microfilament organization, ultimately resulting in inhibited pollen tube elongation. In conclusion, we propose that extracellular AMP, as a hydrolysis product of eATP, also plays a significant role in regulating P. meyeri pollen germination and tube growth in vitro. Full article

Residential greening is a critical strategy for mitigating the negative impacts of urbanization on the environment, biodiversity, and human well-being. Proper plant species selection is essential for the success of residential greening projects, as it influences the ecological, aesthetic, and health outcomes. This review provides a comprehensive framework for selecting plant species for residential greening, considering environmental suitability, aesthetic values, maintenance requirements, and potential health effects. The plant’s adaptability to local climatic conditions, soil type, and water availability are key considerations. Aesthetic factors like plant form, texture, color, and seasonal interest should be balanced with maintenance needs, including pruning, fertilization, and pest control. Potential health concerns, like allergenic pollen or toxic properties, must also be evaluated while deploying residential greeneries. The guide emphasizes the importance of selecting native or well-adapted non-invasive species to support local biodiversity and minimize ecological disruption. Employing a systematic approach to plant selection for urban vegetation and residential greening initiatives can enhance the environmental, social, and health benefits. Plant species invasiveness is a critical global concern, with substantial ecological, economic, and social impacts that demand careful consideration in species selection and management. This method maximizes these advantages and promotes long-term sustainability and resilience against the challenges posed by climate change. This present review supports the UN’s Sustainable Development Goal 11: Sustainable Cities and Society. Full article

Cytoplasmic male sterile (CMS) systems have great potential in hybrid seed production in many plants. However, the incompatibility between the cytoplasmic and nuclear genes and the availability of fewer CMS lines limit the system’s application in cotton heterosis. Therefore, the present study sequenced the mitochondrial (mt) genomes of a novel cotton (Gossypium hirsutum L.) CMS line J4A and its cytoplasmic nuclear homologous maintainer line J4B to investigate the mechanism underlying CMS and improve its application. A novel CMS gene, orf116b, was identified in the CMS line. Ectopic expression of orf116b in Escherichia coli suppressed growth, while its overexpression in Arabidopsis, rice, tobacco, and cotton led to complete or partial male sterility. Further analysis of anthers revealed mt disruption in J4A with higher levels of hydrogen peroxide (H₂O₂) and malondialdehyde (MDA), but lower levels of ATP and ribosomal protein (RP) than in J4B. Finally, a membrane-based yeast two-hybrid (MYTH) assay and bimolecular fluorescence complementation (BiFC) assays demonstrated that orf116b probably interacts with an anther-specific protein, LAT52. These observations collectively proved that orf116b is associated with early and stable pollen abortion in cotton, providing a foundation for further research on cotton fertility restoration and heterosis breeding. Full article

The production of statice (Limonium sp.) plants with higher ploidy through induction of whole-genome duplication (WGD) via the spindle disrupter nitrous oxide (N₂O) was examined as a strategy to increase the germplasm diversity of the species. Furthermore, the impact of the resulting ploidy changes on the morphological features of the progeny was examined. Intraspecific crosses between diploid plants of Limonium sinuatum (L.) Mill and L. perezii (Stapf) Hubb. were conducted daily for seven consecutive days, with subsequent exposure to N₂O. Within the resulting progeny, between 16% and 35% of plants were polyploid when N₂O was applied between one and four days after pollination. A comparative analysis between diploid and tetraploid progeny was conducted, using a selection of 10 L. sinuatum (5 diploids and 5 tetraploids) and 7 L. perezii (4 diploids and 3 tetraploids) genotypes. The results revealed differences between tetraploids and their diploid counterparts for most of the evaluated characteristics. Tetraploid plants of L. sinuatum and L. perezii exhibited pollen grains 1.5 times larger in plan area; the leaves and main floral stem diameter were 1.2 and 1.5 times thicker for L. sinuatum and L. perezii, respectively, the guard cell length was 1.4 times greater for both species, while the stomatal density was 0.6 times lower for L. perezii and 0.8 for L. sinuatum. The leaf area and main floral stem wings were affected by the ploidy increase only for L. sinuatum. In this regard, tetraploid plants of L. sinuatum displayed leaves 1.8 times bigger and main floral steam wings 2.4 times wider in comparison to diploid plants. In conclusion, the production of tetraploid Limonium plants using N₂O shortly after pollination creates new diversity for breeding. These findings underscore the potential for leveraging polyploidy as a strategy to enhance desirable traits in Limonium species. Full article

Numerous Aspergillus fumigatus (Af) airborne spores are inhaled daily by humans and animals due to their ubiquitous presence. The interaction between the spores and the respiratory epithelium, as well as its impact on the epithelial barrier function, remains largely unknown. The epithelial barrier protects the respiratory epithelium against viral infections. However, it can be compromised by environmental contaminants such as pollen, thereby increasing susceptibility to respiratory viral infections, including alphaherpesvirus equine herpesvirus type 1 (EHV-1). To determine whether Af spores disrupt the epithelial integrity and enhance susceptibility to viral infections, equine respiratory mucosal ex vivo explants were pretreated with Af spore diffusate, followed by EHV-1 inoculation. Spore proteases were characterized by zymography and identified using mass spectrometry-based proteomics. Proteases of the serine protease, metalloprotease, and aspartic protease groups were identified. Morphological analysis of hematoxylin-eosin (HE)-stained sections of the explants revealed that Af spores induced the desquamation of epithelial cells and a significant increase in intercellular space at high and low concentrations, respectively. The increase in intercellular space in the epithelium caused by Af spore proteases correlated with an increase in EHV-1 infection. Together, our findings demonstrate that Af spore proteases disrupt epithelial integrity, potentially leading to increased viral infection of the respiratory epithelium. Full article

Pollination in angiosperms depends on complex communication between pollen grains and stigmas, classified as wet or dry, depending on the presence or absence of secretions at the stigma surface, respectively. In species with wet stigma, the cuticle is disrupted and the presence of exudates is indicative of their receptivity. Most stigma studies are focused on a few species and families, many of them with self-incompatibility systems. However, there is scarce knowledge about the stigma composition in Fabaceae, the third angiosperm family, whose stigmas have been classified as semidry. Here we report the first transcriptome profiling and DEGs of Vicia faba L. styles and stigmas from autofertile (flowers able to self-fertilize in the absence of manipulation, whose exudate is released spontaneously) and autosterile (flowers that need to be manipulated to break the cuticle and release the exudates to be receptive) inbred lines. From the 76,269 contigs obtained from the de novo assembly, only 45.1% of the sequences were annotated with at least one GO term. A total of 115,920, 75,489, and 70,801 annotations were assigned to Biological Process (BP), Cellular Component (CC), and Molecular Function (MF) categories, respectively, and 5918 differentially expressed genes (DEGs) were identified between the autofertile and the autosterile lines. Among the most enriched metabolic pathways in the DEGs subset were those related with amino acid biosynthesis, terpenoid metabolism, or signal transduction. Some DEGs have been related with previous QTLs identified for autofertility traits, and their putative functions are discussed. The results derived from this work provide an important transcriptomic reference for style-stigma processes to aid our understanding of the molecular mechanisms involved in faba bean fertilization. Full article

Reconstructing Holocene vegetation history and human impact on vegetation is critical for understanding past interactions between humans and nature. This study concentrates on the lower West River area in Southern China, offering high-resolution reconstructions of vegetation changes over the last 9000 years. Our findings reveal that during the Holocene Climatic Optimum (9–5 ka BP), the area was predominantly covered by dense evergreen broad-leaved forests. Around 5.1 ka BP, the emergence of marsh forests, as evidenced by abundant pollen of Glyptostrobus and in situ buried woods and roots, indicated a transition towards a wetland ecosystem. Notably, a thriving wetland environment and high production of peat deposits dating from 4.3 ka to 2.5 ka BP reflect the continuous drop of lake levels and the formation of swamps driven by a climatic pattern marked by decreased precipitation, potentially linked to a reduction in summer monsoon intensity during the latter part of the Holocene. This period of wetland expansion also coincides with the earliest evidence of rice cultivation in Southern China, suggesting a relationship between agricultural development and regional landscape changes. Additionally, millennial-scale paleo-megafloods are not only identified by lithological features but also by pollen taxa and principal component analysis. Despite the temporary disruptions of the marsh forest, it demonstrated resilience, quickly recovering within decades. By approximately 2.5 ka BP, a significant increase in rice-type Poaceae pollen and Pteridophyte spores, alongside the sharp decline of Glyptostrobus and a decrease in arboreal taxa, were observed. This shift in pollen spectra, coupled with a PC1 curve of principal component analysis, points to intensified human activity as a primary driver behind the collapse of the local wetland ecosystem. These findings align with regional evidence from the Pearl River Delta and coastal Southern China, highlighting extensive human intervention in natural forests and the onset of large-scale agriculture post-2.5 ka BP. Full article

Although the plants of the genus Euphorbia are largely exploited by therapists in Morocco, the composition and antibacterial activities of propolis from these plants are still unknown. To address this gap, this study aimed to characterize the pollen type, the volatile compounds, and the phenolic and mineral profiles of three Euphorbia propolis samples collected in Morocco and evaluate their antimicrobial activities. The minimum inhibitory concentration of the propolis samples was determined by the microdilution method, and the anti-adherence activity was evaluated by the crystal violet assay. The examination of anti-quorum-sensing proprieties was performed using the biosensor Chromobacterium violaceum CV026. Pollen analysis revealed that Euphorbia resinifera pollen dominated in the P1 sample (58%), while E. officinarum pollen dominated in the P2 and P3 samples (44%). The volatile compounds were primarily composed of monoterpene hydrocarbons, constituting 35% in P1 and 31% in P2, with α-pinene being the major component in both cases, at 16% in P1 and 15% in P2. Calcium (Ca) was the predominant mineral element in both E. resinifera (P1) and E. officinarum (P2 and P3) propolis samples. Higher levels of phenols, flavonoids and dihydroflavonoids were detected in the E. officinarum P2 sample. The minimum inhibitory concentration (MIC) value ranged from 50 to 450 µL/mL against Gram-positive and Gram-negative bacteria. Euphorbia propolis displayed the ability to inhibit quorum sensing in the biosensor C. violaceum CV026 and disrupted bacterial biofilm formation, including that of resistant bacterial pathogens. In summary, the current study evidences the potential use of E. officinarum propolis (P2 and P3) to combat important features of resistant pathogenic bacteria, such as quorum sensing and biofilm formation. Full article

Lilies are well−known flowers with large anthers and a high quantity of pollen that easily contaminates clothing and tepals. The anthers need to be artificially removed, leading to production problems. Cultivating male−sterile or pollen−free lilies could solve these problems. The key period of male sterility in a specific male−sterile hybrid lily population was determined through cytological observation. The contents of hormones, soluble sugar, soluble protein, and proline were determined by high−performance liquid chromatography, tandem mass spectrometry and colorimetry. Transcriptome sequencing was used to identify the genes with altered expression. The key period of male sterility was determined to be the microspore mother and tetrad stages. The hormone contents were abnormal in the sterile line compared with the fertile line. The indole−3−acetic acid (IAA) content was higher in the sterile line than in the fertile line at all stages, while the gibberellic acid 4 (GA4) content showed the opposite result. Abscisic acid (ABA) accumulated in the sterile line in both the microspore mother and tetrad stages, and the zeatin riboside (ZR) content in the sterile line increased at the microspore mother stage but decreased at the tetrad stage. The contents of soluble sugar, soluble protein and proline were higher in the fertile line than in the sterile line. Genes involved in auxin and ABA synthesis and signalling pathways were highly expressed in the male−sterile line. Our data suggested that abnormal contents of hormones in the microspore mother and tetrad stages resulted in pollen abortion in a male−sterile hybrid lily population, which indicated that the hormone balance in specific stages plays critical functions in pollen development in lilies. Full article

Honey bees coexist with fungi that colonize hive surfaces and pollen. Some of these fungi are opportunistic pathogens, but many are beneficial species that produce antimicrobial compounds for pollen conservation and the regulation of pathogen populations. In this study, we tested the in vitro antimicrobial activity of Talaromyces purpureogenus strains isolated from bee bread against Paenibacillus alvei (associated with European foulbrood disease) and three Aspergillus species that cause stonebrood disease. We found that methanol extracts of T. purpureogenus strains B18 and B195 inhibited the growth of P. alvei at a concentration of 0.39 mg/mL. Bioactivity-guided dereplication revealed that the activity of the crude extracts correlated with the presence of diketopiperazines, a siderophore, and three unknown compounds. We propose that non-pathogenic fungi such as Talaromyces spp. and their metabolites in bee bread could be an important requirement to prevent disease. Agricultural practices involving the use of fungicides can disrupt the fungal community and thus negatively affect the health of bee colonies. Full article