PREMISE: Animal-pollinated plants face a high risk of pollen loss during its transfer. To limit the negative effect of pollen losses by pollen consumption and heterospecific transfer, plant species may adjust and stratify their pollen availability during the day (i.e., "schedule" their pollen presentation) and attract pollinators in specific time frames. METHODS: We investigated diurnal patterns of pollen availability and pollinator visitation in three coflowering plant species: Succisa pratensis with open flowers and accessible pollen, pollinated mainly by pollen-feeding hoverflies; Centaurea jacea with open flowers and less accessible pollen, pollinated mainly by pollen-collecting bees; and Trifolium hybridum with closed flowers and pollen accessible only after the active opening of the flower, pollinated exclusively by bees. RESULTS: The three plant species differed in the peak pollen availability, tracked by the visitation activity of their pollinators. Succisa pratensis released all pollen in the morning, while pollinator activity was still low and peaked with a slight delay. In contrast, C. jacea and T. hybridum had distinct pollen presentation schedules, peaking in the early afternoon. The pollinator visitation to both of these species closely matched their pollen availability. CONCLUSIONS: Stratifying pollen availability to pollinators during the day may be one of several mechanisms that allow coflowering plants to share their pollinators and decrease the probability of heterospecific pollen transfer.

• Klíčová slova
• Centaurea jacea, Succisa pratensis, Trifolium hybridum, plant sexual reproduction, pollen presentation, pollen release schedule, pollen transfer, pollinator diurnal activity,
• MeSH
• Centaurea * MeSH
• květy MeSH
• opylení * MeSH
• pyl MeSH
• rostliny MeSH
• včely MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Ozone exacerbates allergy symptoms to certain pollens. The molecular mechanisms by which ozone affects pollen grains (PGs) and allergies are not fully understood, especially as the effects of pollutants may vary depending on the type of pollen. In this work, pollens of 22 different taxa were exposed under laboratory conditions to ozone (100 ppb) to quantify the ozone uptake by the PGs. The ozone uptake was highly variable among the 22 taxa tested. The highest ozone uptake per PG was measured on Acer negundo PGs (2.5 ± 0.2 pg∙PG-1). On average, tree pollens captured significantly more ozone than herbaceous pollens (average values of 0.5 and 0.02 pg∙PG-1, respectively). No single parameter (such as the number of apertures, pollen season, pollen size, or lipid fraction) could predict a pollen's ability to take up ozone. Lipids seem to act as a barrier to ozone uptake and play a protective role for some taxa. After inhalation of PGs, pollen-transported ozone could be transferred to mucous membranes and exacerbate symptoms through oxidative stress and local inflammation. Although the amount of ozone transported is small in absolute terms, it is significant compared to the antioxidant capacity of nasal mucus at a microscale. This mechanism of pollen-induced oxidative stress could explain the aggravation of allergic symptoms during ozone pollution episodes.

• Klíčová slova
• Air pollution, Allergy, Atmospheric biochemistry, Bioaerosol, Oxidative stress,
• MeSH
• alergeny MeSH
• alergie * MeSH
• látky znečišťující životní prostředí * MeSH
• ozon * toxicita   MeSH
• pyl MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• alergeny MeSH
• látky znečišťující životní prostředí * MeSH
• ozon * MeSH

Melissopalynology is an important analytical method to identify botanical origin of honey. Pollen grain recognition is commonly performed by visual inspection by a trained person. An alternative method for visual inspection is automated pollen analysis based on the image analysis technique. Image analysis transfers visual information to mathematical descriptions. In this work, the suitability of three microscopic techniques for automatic analysis of pollen grains was studied. 2D and 3D morphological characteristics, textural and colour features, and extended depth of focus characteristics were used for the pollen discrimination. In this study, 7 botanical taxa and a total of 2482 pollen grains were evaluated. The highest correct classification rate of 93.05% was achieved using the phase contrast microscopy, followed by the dark field microscopy reaching 91.02%, and finally by the light field microscopy reaching 88.88%. The most significant discriminant characteristics were morphological (2D and 3D) and colour characteristics. Our results confirm the potential of using automatic pollen analysis to discriminate pollen taxa in honey. This work provides the basis for further research where the taxa dataset will be increased, and new descriptors will be studied.

• MeSH
• barva MeSH
• med analýza   MeSH
• mikroskopie metody   MeSH
• počítačové zpracování obrazu metody   MeSH
• pyl klasifikace   MeSH
• včelařství * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH

Climate change poses an unprecedented threat to forest ecosystems, necessitating innovative adaptation strategies. Traditional assisted migration approaches, while promising, face challenges related to environmental constraints, forestry practices, phytosanitary risks, economic barriers, and legal constraints. This has sparked debate within the scientific community, with some advocating for the broader implementation of assisted migration despite these limitations, while others emphasize the importance of local adaptation, which may not keep pace with the rapid rate of climate change. This opinion paper proposes a novel pollen-based assisted migration strategy as a potential middle ground in this debate. By leveraging existing seed orchard infrastructure for controlled pollen transfer, this approach aims to enhance forest resilience through the introduction of genetic material from climatically suitable sources while acknowledging local adaptation. We assess the genetic implications of the proposed strategy through computer simulation. Additionally, we examine the ecological implications of assisted gene flow, discussing the potential benefits of heterosis and the risks of outbreeding depression in intra-specific hybrid populations. We further explore the advantages of pollen-based migration in mitigating phytosanitary risks, reducing economic barriers, and simplifying legal considerations compared to traditional seed or seedling transfer methods. Regional perspectives on adapting pollen-based assisted migration are provided, with specific examples from Northern and Central Europe. We highlight how this approach could be integrated into existing forestry practices and regulatory frameworks within the European Union. We conclude by advocating for the inclusion of pollen-based assisted migration in future international projects and operational forestry, emphasizing the need for adaptable policies that can support innovative forest management strategies in the face of climate change.

• Klíčová slova
• forest nurseries, forestry policy, gene flow, genetic diversity, heterosis, natural selection, phytosanitary risks, seed orchards,
• MeSH
• fyziologická adaptace MeSH
• klimatické změny * MeSH
• lesnictví * metody   MeSH
• lesy * MeSH
• pyl * MeSH
• tok genů MeSH
• zachování přírodních zdrojů metody   MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Evropa MeSH

One of the most vulnerable phases in the plant life cycle is sexual reproduction, which depends on effective pollen transfer, but also on the thermotolerance of pollen grains. Pollen thermotolerance is temperature-dependent and may be reduced by increasing temperature associated with global warming. A growing body of research has focused on the effect of increased temperature on pollen thermotolerance in crops to understand the possible impact of temperature extremes on yield. Yet, little is known about the effects of temperature on pollen thermotolerance of wild plant species. To fill this gap, we selected Lotus corniculatus s.l. (Fabaceae), a species common to many European habitats and conducted laboratory experiments to test its pollen thermotolerance in response to artificial increase in temperature. To test for possible local adaptation of pollen thermal tolerance, we compared data from six lowland (389-451 m a.s.l.) and six highland (841-1,030 m a.s.l.) populations. We observed pollen germination in vitro at 15 °C, 25 °C, 30 °C, and 40 °C. While lowland plants maintained a stable germination percentage across a broad temperature range (15-30 °C) and exhibited reduced germination only at extremely high temperatures (40 °C), highland plants experienced reduced germination even at 30 °C-temperatures commonly exceeded in lowlands during warm summers. This suggests that lowland populations of L. corniculatus may be locally adapted to higher temperature for pollen germination. On the other hand, pollen tube length decreased with increasing temperature in a similar way in lowland and highland plants. The overall average pollen germination percentage significantly differed between lowland and highland populations, with highland populations displaying higher germination percentage. On the other hand, the average pollen tube length was slightly smaller in highland populations. In conclusion, we found that pollen thermotolerance of L. corniculatus is reduced at high temperature and that the germination of pollen from plant populations growing at higher elevations is more sensitive to increased temperature, which suggests possible local adaptation of pollen thermotolerance.

• Klíčová slova
• Elevational gradient, Heat stress, Local adaptation, Plant reproduction, Pollen, Pollen viability, Pollination, Thermotolerance,
• MeSH
• aklimatizace fyziologie   MeSH
• fyziologická adaptace fyziologie   MeSH
• globální oteplování MeSH
• klíčení fyziologie   MeSH
• klimatické změny MeSH
• Lotus * fyziologie   růst a vývoj   MeSH
• nadmořská výška MeSH
• pyl * fyziologie   MeSH
• teplota MeSH
• termotolerance * fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Molecular diagnosis of allergy and microarray technology have opened a completely new avenue of insight into sensitization profiles from both the clinical and the epidemiological point of view. We used this innovative tool in the description of sensitization patterns in pollen-sensitized patients in Middle Europe. Immunoglobulin E detection using 112 different allergenic molecules was carried out employing the ImmunoCAP ISAC microarray system. Sera from 826 patients sensitized to at least one pollen-derived molecule were subjected to analysis. The highest observed sensitization rate was 81.0% to grass-specific molecules (the most frequent being Phl p 1; 69.6%). The second most frequent sensitization was 54.8% to Betulaceae-specific molecules (Bet v 1; 54.2%). Together, grasses and Betulaceae components (and their cosensitizations with other components) comprised the vast majority of pollen sensitizations. Unexpectedly frequently observed sensitizations were those to Cupressaceae-specific molecules (14.1%), Oleaceae-specific molecules (10.8%), and the plane tree-derived molecule Pla a 2 (15.5%). The sensitization rates for all other molecules were within the expected range (Art v 1, 13.6%; Pla l 1, 9.6%; Che a 1, 8.4%; Par j 2, 0.9%; Amb a 1, 0.8%, and Sal k 1, 0.5%). Cross-reacting molecule sensitization rates were found to be 12.4% for profilins, 5.0% for polcalcins, and 6.4% for lipid transfer proteins. Molecular diagnosis of allergy gives a more precise and comprehensive insight into pollen sensitization patterns than extract-based testing, allowing a better understanding of the sensitization process and regional differences. The data presented here may help to improve the diagnostic and allergen-specific treatment procedures in the respective region.

• MeSH
• alergeny imunologie   MeSH
• imunoanalýza MeSH
• lidé MeSH
• mikročipová analýza MeSH
• pyl imunologie   MeSH
• retrospektivní studie MeSH
• sezónní alergická rýma epidemiologie   etiologie   imunologie   MeSH
• zkřížené reakce MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Evropa epidemiologie   MeSH
• Názvy látek
• alergeny MeSH

Some viroids-single-stranded, non-coding, circular RNA parasites of plants-are not transmissible through pollen to seeds and to next generation. We analyzed the cause for the elimination of apple fruit crinkle viroid (AFCVd) and citrus bark cracking viroid (CBCVd) from male gametophyte cells of Nicotiana tabacum by RNA deep sequencing and molecular methods using infected and transformed tobacco pollen tissues at different developmental stages. AFCVd was not transferable from pollen to seeds in reciprocal pollinations, due to a complete viroid eradication during the last steps of pollen development and fertilization. In pollen, the viroid replication pathway proceeds with detectable replication intermediates, but is dramatically depressed in comparison to leaves. Specific and unspecific viroid degradation with some preference for (-) chains occurred in pollen, as detected by analysis of viroid-derived small RNAs, by quantification of viroid levels and by detection of viroid degradation products forming "comets" on Northern blots. The decrease of viroid levels during pollen development correlated with mRNA accumulation of several RNA-degrading factors, such as AGO5 nuclease, DICER-like and TUDOR S-like nuclease. In addition, the functional status of pollen, as a tissue with high ribosome content, could play a role during suppression of AFCVd replication involving transcription factors IIIA and ribosomal protein L5.

• Klíčová slova
• AFCVd and CBCVd propagation and eradication, Nicotiana tabacum, TUDOR S-nuclease, male gametophyte, recombinant AGO, small RNA, strand-specific viroid RT-qPCR, viroid degradation, viroid replication,
• MeSH
• fenotyp MeSH
• interakce hostitele a patogenu MeSH
• konformace nukleové kyseliny MeSH
• nemoci rostlin virologie   MeSH
• pyl virologie   MeSH
• replikace viru MeSH
• RNA virová MeSH
• tabák virologie   MeSH
• viroidy * MeSH
• virová nálož MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• RNA virová MeSH

Cypress pollen represents the primary cause of respiratory allergies in Mediterranean areas. Patients allergic to Cupressus sempervirens pollen (Cups) (CPA) can be discriminated on the basis of the immunoglobulin E (IgE) binding to a basic 14 kDa protein (BP14) or to high-molecular-weight (HMW) glycoproteins only. Specific IgE repertoires of two differentially exposed CPA cohorts, French and Italian, were investigated using an IgE microarray system (some known major allergens from several allergenic sources) and individual IgE immunoblotting (IB) of whole Cups pollen extract separated by SDS-PAGE (all allergens from one allergenic source: cypress pollen). The prevalence of sensitization to BP14 was higher in French (37 %) than in Italian patients (17 %) and major differences were observed in IgE reactivities to lipid transfer proteins (LTPs). Thirty percent of the Italian CPA (4 % in the French group) had specific IgE against the Parietaria pollen LTP, independently of IB subgroups. Regarding peach LTP sensitization, all Pru p 3+ Italian CPA (10 %) were in the HMW+ subgroup, while Pru p 3+ French CPA (20 %) were all included in the BP14+ subgroup. BP14 sensitization is likely a marker of Cups exposure and is, in French CPA, significantly correlated to Pru p 3 sensitization. The IgE immunoblot and microarray are complementary tools that highlight differences in the subtle sensitization profile between groups of patients in comparative studies.

• MeSH
• alergeny imunologie   MeSH
• alergie epidemiologie   imunologie   MeSH
• cypřiš (rod) chemie   MeSH
• dítě MeSH
• dospělí MeSH
• imunizace MeSH
• imunoblotting metody   MeSH
• imunoglobulin E imunologie   MeSH
• kohortové studie MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• prevalence MeSH
• pyl imunologie   MeSH
• rostlinné proteiny imunologie   MeSH
• sekvenční analýza hybridizací s uspořádaným souborem oligonukleotidů metody   MeSH
• senioři MeSH
• transportní proteiny imunologie   MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Geografické názvy
• Francie MeSH
• Itálie epidemiologie   MeSH
• Názvy látek
• alergeny MeSH
• imunoglobulin E MeSH
• lipid transfer protein MeSH Prohlížeč
• rostlinné proteiny MeSH
• transportní proteiny MeSH

The plant life cycle is often affected by animal-plant interactions. In insect-pollinated plants, interaction with pollinators is very important. When pollen transfer due to a lower abundance of pollinators limits seed production, selection pressures on plant traits related to plant attraction to pollinators might occur, e.g. on flowering phenology, height or number of flowerheads. Landscape changes (e.g. habitat fragmentation or changed habitat conditions) may cause plant-pollinator systems to lose balance and consequently affect population dynamics of many plant species. We studied the relationship between measured plant traits, environmental variables and pollinator preferences in Scorzonera hispanica (Asteraceae), a rare perennial, allogamous herb of open grasslands. We estimated the pollen limitation by comparing seed set of supplemental-pollinated plants with that of open-pollinated ones. Pollinators selected plants based on position within the locality (isolated plants close to trees) rather than on their traits. In spite of a high proportion of undeveloped seeds on the plants, we demonstrated that they are not pollen limited. Instead, seed set and weight of seeds was correlated with plant size traits (height and flowerhead number), with larger plants producing more and larger seeds. This suggests that the studied plants are likely resource limited. Overall, the results suggest that pollinators are not a selection factor in this system, in contrast to studies on various plant species, including self-compatible species of the Asteraceae. The lack of any effect of pollinators in the system may be caused by a strong negative effect of ungulate herbivores, which could play a decisive role in functioning of the system.

• Klíčová slova
• Evolution, floral display, generative reproduction, heritability, outcrossing,
• MeSH
• chování zvířat MeSH
• ekosystém MeSH
• hmyz fyziologie   MeSH
• květy anatomie a histologie   růst a vývoj   fyziologie   MeSH
• opylení * MeSH
• populační dynamika MeSH
• rozmnožování MeSH
• Scorzonera anatomie a histologie   růst a vývoj   fyziologie   MeSH
• selekce (genetika) MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Herein, a three-dimensional (3D) Fe3O4@C composite with hollow porous structure is prepared by simple solution method and calcination treatment with biomass waste rape pollen (RP) as a carbon source, which is served as an anode of Li-ion capacitor (LIC). The 3D interconnected porous structure and conductive networks facilitate the transfer of ion/electron and accommodate the volume changes of Fe3O4 during the electrochemical reaction process, which leads to the excellent performance of the Fe3O4@C composite electrode. The electrochemical analysis demonstrates that the hybrid LIC fabricated with Fe3O4@C as the anode and activated carbon (AC) as the cathode can operate at a voltage of 4.0 V and exhibit a high energy density of 140.6 Wh kg-1 at 200 W kg-1 (52.8 Wh kg-1 at 10 kW kg-1), along with excellent cycling stability, with a capacity retention of 83.3% over 6000 cycles. Hence, these encouraging results indicate that Fe3O4@C has great potential in developing advanced LICs electrode materials for the next generation of energy storage systems.

• Klíčová slova
• Fe3O4, Li-ion capacitor, electrochemical properties, porous carbon,
• Publikační typ
• časopisecké články MeSH