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Proceedings of the Royal Society of... Aug 1975
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Molecules (Basel, Switzerland) Nov 2022Attempts have often been made to isolate and characterise monofloral pollens to correlate nutritional with botanical properties. Nevertheless, pollen harvested in a...
Characterisation of Bee Pollen from the Marche Region (Italy) According to the Botanical and Geographical Origin with Analysis of Antioxidant Activity and Colour, Using a Chemometric Approach.
Attempts have often been made to isolate and characterise monofloral pollens to correlate nutritional with botanical properties. Nevertheless, pollen harvested in a particular area that can have a high biodiversity could have healthier properties. In addition, the analysis of the pollen's botanical composition can be important for characterising the typical flora of a specific geographical area. On this basis, various pollens collected in different locations of the Marche region (Italy) and in different harvesting periods were analyzed for botanical composition and antioxidant (total phenolic content, ABTS, DPPH and ORAC tests), granulometry and colour (CIE L*a*b*) properties to evaluate the biodiversity of pollen sources within a particular geographical area and to correlate this to the nutraceutical characteristics. Antioxidant activity results showed values generally higher than those of monofloral pollens harvested in the same areas but manually separated according to colour, shape and size. This suggests that even the floral species present in low percentages may have an influence on the nutraceutical properties of these products. The multivariate statistical elaboration of the obtained results permitted the separation of samples containing a prevalent botanical species and the grouping of all the samples into separate clusters corresponding to different areas of Marche.
Topics: Animals; Antioxidants; Bees; Chemometrics; Color; Phenols; Pollen
PubMed: 36432097
DOI: 10.3390/molecules27227996 -
Biophysical Journal Mar 2022The structure of pollen grains, which is typically characterized by soft apertures in an otherwise stiff exine shell, guides their response to changes in the humidity of...
The structure of pollen grains, which is typically characterized by soft apertures in an otherwise stiff exine shell, guides their response to changes in the humidity of the environment. These changes can lead to desiccation of the grain and its infolding but also to excessive swelling of the grain and even its bursting. Here we use an elastic model to explore the mechanics of pollen grain swelling and the role of soft, circular apertures (pores) in this process. Small, circular apertures typically occur in airborne and allergenic pollen grains so that the bursting of such grains is important in the context of human health. We identify and quantify a mechanical weakness of the pores, which are prone to rapid inflation when the grain swells to a critical extent. The inflation occurs as a sudden transition and may induce bursting of the grain and release of its content. This process crucially depends on the size of the pores and their softness. Our results provide insight into the inactive part of the mechanical response of pollen grains to hydration when they land on a stigma as well as bursting of airborne pollen grains during changes in air humidity.
Topics: Allergens; Humans; Pollen
PubMed: 35093340
DOI: 10.1016/j.bpj.2022.01.019 -
Plant & Cell Physiology Jul 2022Plant High-affinity K+ transporters/K+ uptake permeases/K+ transporters (HAK/KUP/KT) transporters have been predicted as membrane H+-K+ symporters in facilitating K+...
Plant High-affinity K+ transporters/K+ uptake permeases/K+ transporters (HAK/KUP/KT) transporters have been predicted as membrane H+-K+ symporters in facilitating K+ uptake and distribution, while their role in seed production remains to be elucidated. In this study, we report that OsHAK26 is preferentially expressed in anthers and seed husks and located in the Golgi apparatus. Knockout of either OsHAK26 or plasma membrane located H+-K+ symporter gene OsHAK1 or OsHAK5 in both Nipponbare and Dongjin cultivars caused distorted anthers, reduced number and germination rate of pollen grains. Seed-setting rate assay by reciprocal cross-pollination between the mutants of oshak26, oshak1, oshak5 and their wild types confirmed that each HAK transporter is foremost for pollen viability, seed-setting and grain yield. Intriguingly, the pollens of oshak26 showed much thinner wall and were more vulnerable to desiccation than those of oshak1 or oshak5. In vitro assay revealed that the pollen germination rate of oshak5 was dramatically affected by external K+ concentration. The results suggest that the role of OsHAK26 in maintaining pollen development and fertility may relate to its proper cargo sorting for construction of pollen walls, while the role of OsHAK1 and OsHAK5 in maintaining seed production likely relates to their transcellular K+ transport activity.
Topics: Fertility; Gene Expression Regulation, Plant; Membrane Transport Proteins; Oryza; Plant Proteins; Pollen; Potassium
PubMed: 35536598
DOI: 10.1093/pcp/pcac061 -
Plant Reproduction Dec 2019We found a correlation between large pollens and selfing and between psilate pollen walls and cleistogamy. Flowering plants display extraordinary diversity in pollen...
We found a correlation between large pollens and selfing and between psilate pollen walls and cleistogamy. Flowering plants display extraordinary diversity in pollen morphology, yet the functional significance of this variation is not well understood. Zygophylloideae is a lineage characterized by high diversity of breeding systems, ranging from obligate selfing to facultative selfing and further to facultative outcrossing. This group is particularly suitable for testing hypotheses about the influence of breeding system on pollen morphology. We studied pollen morphology in 20 species of Zygophylloideae and one species of Tribuloideae as an outgroup. A phylogeny of Zygophylloideae was created based on available DNA sequences and used to trace the evolution of pollen characters. We performed a phylogenetic analysis of correlated evolution between breeding system and several pollen characters. Three types of pollen morphology were found in the studied species. Tricolporate pollen with a small apocolpium, microreticulate ornamentation and medium size was determined as the ancestral state in Zygophylloideae. The correlation analysis indicated an association between large pollens and selfing and between psilate pollen wall and cleistogamy. We hypothesize that large size of pollen in selfing species is mainly associated with the low number of produced pollen indicating a trade-off between pollen size and number. The independence from pollen vector in cleistogamous flowers accounts for the evolution of smooth pollen walls in these species.
Topics: Flowers; Phylogeny; Plant Breeding; Pollen; Reproduction; Zygophyllaceae
PubMed: 31637522
DOI: 10.1007/s00497-019-00379-4 -
Sensors (Basel, Switzerland) Jul 2022Pollen grains strongly affect human health by inducing allergies. Although the monitoring of airborne pollens particles is of major importance, the current measurement...
Pollen grains strongly affect human health by inducing allergies. Although the monitoring of airborne pollens particles is of major importance, the current measurement methods are manually conducted and are expensive, limiting the number of monitoring stations. Thus, there is a need for relatively low-cost instruments that can work automatically. The possible detection of pollen in urban ambient air (Paris, France) has been reported using the LOAC optical aerosol counter. These measurements indicate that the pollen grains and their nature could be determined using their scattering properties. For this purpose, the scattering functions (intensity and linear polarization) of 21 different airborne pollens were established in the laboratory using a PROGRA2 instrument. The linear polarization curves were close together, with a maximum polarization lower than 10% in the red domain and 5% in the green domain. The variability from one sample to another was partly due to the different sizes of the grains. An instrument with an absolute accuracy of about ±1% for polarization measurements should then be needed, coupled with a counting instrument to take into account the effects of size. On the other hand, the scattering curves for intensity presented with different shapes and strong differences up to a factor of 20 at some scattering angles, due to the size, shape, surface texture, and composition of the grains. Thus, we propose a proof of concept for new automated sensors that can be used in dense networks to count and identify pollen grains by analyzing the light they scatter at some specific angles.
Topics: Aerosols; Air; Air Pollutants; Environmental Monitoring; Humans; Pollen
PubMed: 35808483
DOI: 10.3390/s22134984 -
Zhonghua Yu Fang Yi Xue Za Zhi [Chinese... Sep 2023To investigate the species, concentration and seasonal trends of main airborne allergenic pollen in 4 districts and 5 counties of Hohhot City. The Department of...
To investigate the species, concentration and seasonal trends of main airborne allergenic pollen in 4 districts and 5 counties of Hohhot City. The Department of allergy, Beijing Shijitan Hospital Affiliated to Capital Medical University conducted a cross-sectional study about monitoring the airborne allergenic pollen from August 1, 2021 to July 31, 2022 by the gravitational method in 4 districts and 5 counties of Hohhot City, which include Yuquan District, Xincheng District, Huimin District, Saihan District, Tuoketuo County, Helingeer County, Tumotezuoqi County, Wuchuan County and Qingshuihe County. Daily pollens were counted and identified by optical microscopy, and the data were analyzed. The airborne allergenic pollen was collected every month all year round in 4 districts and 5 counties of Hohhot city. Through the whole year of the total quantity of pollens ranged from 24 850 to 50 154 grains per 1 000 mm and two peaks of pollen concentration in air were observed,which happened in spring (from March to May) and in summer and autumn (from July to September). In spring, the main pollens were tree pollens, which principally distributed in Populus pollen (18.29%), Ulmus pollen (8.36%), Pinus pollen (6.20%), Cupressaceae pollen (5.23%), Betulaceae pollen (2.73%), Salix pollen (1.80%) and Quercus pollen (1.16%). In summer and autumn, the main pollens were weed pollens, which mainly included Artemisia pollen (42.73%), Chenopodiaceae pollen or Amaranthaceae pollen (7.46%), Poaceae pollen (2.26%), Humulus pollen or Cannabis pollen (0.60%). There were two peaks of main airborne allergenic pollen in 4 districts and 5 counties of Hohhot City. In the spring peak of pollen, the main airborne pollens were tree pollens. In the summer and autumn peak of pollen, the main airborne pollens were weed pollens. The Artemisia pollen was the most major airborne pollen in this area.
Topics: Humans; Cross-Sectional Studies; Pollen; Hospitals
PubMed: 37743296
DOI: 10.3760/cma.j.cn112150-20230116-00034 -
Sexual Plant Reproduction Mar 2010Expansive growth in plant cells is a formidable problem for biophysical studies, and the mechanical principles governing the generation of complex cellular geometries... (Review)
Review
Expansive growth in plant cells is a formidable problem for biophysical studies, and the mechanical principles governing the generation of complex cellular geometries are still poorly understood. Pollen, the male gametophyte stage of the flowering plants, is an excellent model system for the investigation of the mechanics of complex growth processes. The initiation of pollen tube growth requires first of all, the spatially confined formation of a protuberance. This process must be controlled by the mechanical properties of the cell wall, since turgor is a non-vectorial force. In the elongating tube, cell wall expansion is confined to the apex of the cell, requiring the tubular region to be stabilized against turgor-induced tensile stress. Tip focused surface expansion must be coordinated with the supply of cell wall material to this region requiring the precise, logistical control of intracellular transport processes. The advantage of such a demanding mechanism is the high efficiency it confers on the pollen tube in leading an invasive way of life.
Topics: Biomechanical Phenomena; Cell Wall; Models, Biological; Pollen; Pollen Tube
PubMed: 20165964
DOI: 10.1007/s00497-009-0121-4 -
Journal of Bioscience and Bioengineering Jan 2009A new method to classify pollen species was developed by monitoring autofluorescence images of pollen grains. The pollens of nine species were selected, and their...
A new method to classify pollen species was developed by monitoring autofluorescence images of pollen grains. The pollens of nine species were selected, and their autofluorescence images were captured by a microscope equipped with a digital camera. The pollen size and the ratio of the blue to red pollen autofluorescence spectra (the B/R ratio) were calculated by image processing. The B/R ratios and pollen size varied among the species. Furthermore, the scatter-plot of pollen size versus the B/R ratio showed that pollen could be classified to the species level using both parameters. The pollen size and B/R ratio were confirmed by means of particle flow image analysis and the fluorescence spectra, respectively. These results suggest that a flow system capable of measuring both scattered light and the autofluorescence of particles could classify and count pollen grains in real time.
Topics: Flow Cytometry; Fluorescence; Fluorescent Dyes; Image Processing, Computer-Assisted; Microscopy, Fluorescence; Models, Statistical; Particle Size; Pollen; Scattering, Radiation; Spectrometry, Fluorescence
PubMed: 19147117
DOI: 10.1016/j.jbiosc.2008.10.001 -
Clinical and Experimental Allergy :... Jun 1994Studies employing sera from 34 subjects allergic to white cypress pine (Callitris glaucophylla) pollen identified 18 IgE antibody-binding components in the pollen of...
Studies employing sera from 34 subjects allergic to white cypress pine (Callitris glaucophylla) pollen identified 18 IgE antibody-binding components in the pollen of this species, five of which (MWs approximately 94, 68, 64, 43 and 34 kDa) were recognized by all of the sera. Protein blotting and quantitative inhibition studies revealed clear cross-reactivity between C. glaucophylla and Cupressus sempervirens pollen proteins and striking similarities in the IgE recognition band patterns of the two pollens. Inhibition experiments with other pollen extracts revealed that sera from C. glaucophylla pollen-allergic subjects can be divided into two groups--those inhibited only by extracts from the two Cupressaceae pollens and those inhibited both by these pollen proteins and by pollen extracts from other species. Most of the crossreactions in the latter group cannot be explained on the basis of taxonomic relationships or separate sensitizations. As with previous studies on birch and olive pollens, we conclude that pollen allergenic crossreactivity is much more wide-ranging than generally believed.
Topics: Allergens; Antibody Specificity; Binding, Competitive; Blotting, Western; Cross Reactions; Electrophoresis, Polyacrylamide Gel; Epitopes; Humans; Immunoglobulin E; Plant Proteins; Pollen; Rhinitis, Allergic, Seasonal; Trees
PubMed: 7522944
DOI: 10.1111/j.1365-2222.1994.tb00953.x