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Protoplasma 2001The aim of this paper is to draw attention to partially hydrated pollen, namely, pollen grains having a high water content (> 30%); this type of pollen is more frequent...
The aim of this paper is to draw attention to partially hydrated pollen, namely, pollen grains having a high water content (> 30%); this type of pollen is more frequent than previously thought. Various cyto-physiological strategies are used to retain water during exposure and dispersal such as cytoplasm carbohydrates; in the absence of such strategies, fast pollination must be ensured, because uncontrolled loss of water leads to pollen death. On the other hand, a state of partial hydration allows a fast tube emission (even within 3-5 min). Several methods for determining the hydration status of pollen at anthesis are proposed.
Topics: Carbohydrates; Magnoliopsida; Pollen; Water
PubMed: 11732185
DOI: 10.1007/BF02673869 -
PloS One 2013The breakdown of self-incompatibility, which could result from the accumulation of non-functional S-haplotypes or competitive interaction between two different...
The breakdown of self-incompatibility, which could result from the accumulation of non-functional S-haplotypes or competitive interaction between two different functional S-haplotypes, has been studied extensively at the molecular level in tetraploid Rosaceae species. In this study, two tetraploid Chinese cherry (Prunus pseudocerasus) cultivars and one diploid sweet cherry (Prunus avium) cultivar were used to investigate the ploidy of pollen grains and inheritance of pollen-S alleles. Genetic analysis of the S-genotypes of two intercross-pollinated progenies showed that the pollen grains derived from Chinese cherry cultivars were hetero-diploid, and that the two S-haplotypes were made up of every combination of two of the four possible S-haplotypes. Moreover, the distributions of single S-haplotypes expressed in self- and intercross-pollinated progenies were in disequilibrium. The number of individuals of the two different S-haplotypes was unequal in two self-pollinated and two intercross-pollinated progenies. Notably, the number of individuals containing two different S-haplotypes (S1- and S5-, S5- and S8-, S1- and S4-haplotype) was larger than that of other individuals in the two self-pollinated progenies, indicating that some of these hetero-diploid pollen grains may have the capability to inactivate stylar S-RNase inside the pollen tube and grow better into the ovaries.
Topics: Alleles; Amino Acid Sequence; Cloning, Molecular; Crosses, Genetic; Diploidy; Gene Expression Regulation, Plant; Haplotypes; Molecular Sequence Data; Organ Specificity; Physical Chromosome Mapping; Plant Proteins; Pollen; Prunus; Ribonucleases; Sequence Alignment; Tetraploidy
PubMed: 23596519
DOI: 10.1371/journal.pone.0061219 -
International Journal of Biometeorology Mar 2000The Pinus genus has an elevated pollen production and an anemophilous nature. Although considered to be hypoallergenic, numerous cases of allergies caused by Pinus...
The Pinus genus has an elevated pollen production and an anemophilous nature. Although considered to be hypoallergenic, numerous cases of allergies caused by Pinus pollen have been cited and different authors believe that its allergenicity should be studied in more depth. In the city of Vigo several patients have tested positive for Pinus pollen extracts in skin tests, some of them being mono-sensitive to such pollens. In order to ascertain the behaviour of Pinus pollen and its correlation to the main meteorological factors, we carried out an aerobiological study in the city of Vigo from 1995 to 1998 by using a Hirst active-impact volumetric sporetrap, model Lanzoni VPPS 2000, placed on the left bank of the Vigo estuary (42 degrees 14'15"N, 8 degrees 43'30"W). Pinus has high quantitative importance in the airborne pollen spectrum of the city. It is one of the best represented taxa constituting 13%-20% of the total annual pollen levels. The quantity of Pinus pollen present in the atmosphere of the city of Vigo throughout a year is 5,751 grains (as the average for the sampled years), with a very long pollination period, from the middle of January until May. The maximum concentration was recorded in 1998 with 1,105 grains/m(3) on 3 March, a much greater value than those for the previous years. At the end of its pollination period there is usually a final increase in Pinus pollen concentrations coinciding with the pollination of Pinus silvestris, which are more abundant in mountainous areas far from the city.
Topics: Humans; Hypersensitivity; Pollen; Seasons; Trees; Urban Population; Weather
PubMed: 10789915
DOI: 10.1007/s004840050001 -
Annals of Allergy, Asthma & Immunology... May 1999Clinicians and palynologists (pollen specialists) often have different ways of expressing the same thing when they write about pollen.
BACKGROUND
Clinicians and palynologists (pollen specialists) often have different ways of expressing the same thing when they write about pollen.
OBJECTIVE
This brief paper considers the confusing use of the word pollens that is frequently encountered in medical literature.
METHODS
Three common uses for the word pollens are considered citing examples from clinical literature. The problems associated with each case are explored.
RESULTS
Words and phrases that can serve as suitable alternatives to the word pollens are presented. The advantages of these alternatives are discussed.
CONCLUSION
The word pollens represents a vague usage that obscures the author's intended meaning. Consistent application of the suggested alternatives will enhance the transmission of key concepts in the medical literature.
Topics: Pollen; Terminology as Topic; Writing
PubMed: 10353575
DOI: 10.1016/S1081-1206(10)62719-6 -
International Archives of Allergy and... 1993In this study we reinvestigated the kinetics of allergen release from birch pollen (Betula verrucosa) and timothy grass pollen (Phleum pratense) using different protein...
In this study we reinvestigated the kinetics of allergen release from birch pollen (Betula verrucosa) and timothy grass pollen (Phleum pratense) using different protein extraction procedures, immunoblotting with specific antibodies and immune electron microscopy. Pollen allergens such as the major birch pollen allergen, Bet v I, the major timothy grass pollen allergens, Phl p I and Phl p V, group-II/III allergens from timothy grass and profilins were released rapidly and in large amounts from hydrated pollen. Within a few minutes pollen allergens could be detected in aqueous supernatants prepared from birch and grass pollen with serum IgE or specific antibodies. In parallel the allergen content in the pollen pellet fractions decreased. A nonallergenic protein such as heat shock protein 70 can be extracted in sufficient amounts only with harsh extraction procedures. Immune electron microscopy of dry and rehydrated birch pollens showed that after short hydration, the major birch pollen allergen, Bet v I, migrated into the exine and to the surface of intact pollen grains, whereas profilin, against which a lower percentage of patients is sensitized, was retained in the pollen grain. Comparing the amino acid composition and hydrophilicity of the tested allergens with a nonallergenic protein such as heat shock protein 70, no significant difference was noted. In agreement with earlier observations we conclude that the allergenic properties of proteins are rather linked to the amount and speed of solubility from airborne particles than to intrinsic properties.
Topics: Allergens; Animals; Antibodies, Monoclonal; Contractile Proteins; Electrophoresis, Polyacrylamide Gel; Humans; Hypersensitivity; Immunoblotting; Immunoglobulin E; Kinetics; Mice; Microfilament Proteins; Microscopy, Immunoelectron; Poaceae; Pollen; Profilins; Solubility; Trees
PubMed: 8400895
DOI: 10.1159/000236567 -
Journal of Plant Research Apr 2003We document distyly in Damnacanthus (Rubiaceae) and investigate pollen morphology in the genus. Within nine taxa in Japan (four species, four varieties and one form),...
We document distyly in Damnacanthus (Rubiaceae) and investigate pollen morphology in the genus. Within nine taxa in Japan (four species, four varieties and one form), five show distyly. Non-distylous taxa of Damnacanthus always have a long style and short stamens. We examined the pollen morphology of all taxa of Damnacanthus in Japan. The pollen grains of Damnacanthus are 3- to 5-orthocolporate or sometimes loxocolporate. Polymorphic pollen is sometimes observed even within a single flower. Pollen dimorphism is associated with distyly; pollen grains from short-styled (thrum) flowers are significantly larger than those from long-styled (pin) flowers, and the muri are smooth in pin flowers whereas the pollen grains of thrum flowers have minute granules on the top and/or on the sides. In non-distylous taxa, in which the style is longer than stamens, the muri are always provided with minute granules. Interestingly, the pollen grains with granules in the non-distylous taxa contrast with the pollen of the distylous taxa, because granulate pollen grains are found only in thrum flowers. Although Damnacanthus is a stenopalynous genus, the number of colpi is useful for delimiting taxa. Based on palynological characters, we conclude that Damnacanthus should be revised.
Topics: Pollen; Rubiaceae; Species Specificity
PubMed: 12736782
DOI: 10.1007/s10265-002-0075-1 -
California Medicine Dec 1959Observation of 100 patients with atopic dermatitis due to hypersensitivity to pollen over a period of 12 years emphasized certain important diagnostic and therapeutic...
Observation of 100 patients with atopic dermatitis due to hypersensitivity to pollen over a period of 12 years emphasized certain important diagnostic and therapeutic features. The incidence was higher in females than in males and higher in middle and old age than in the earlier years. Pollen dermatitis may be the sole or major manifestation of allergy; 43 patients gave no history of other allergic symptoms. It may involve any or all areas of the body. The site or the distribution of lesions or the nature of the lesions gave no clue as to the diagnosis of pollen sensitivity. The character of the eruption varied widely from patient to patient and in given patients from week to week at times. Atopic dermatitis due to pollen sensitivity may be purely seasonal, perennial with seasonal exacerbations or perennial without seasonal variation. Reactions to skin testing with pollens suspected as allergens may be positive, equivocal or negative. In 58 patients there were positive correlative skin reactions to pollens. The diagnosis of atopic dermatitis due to pollen sensitivity, and the composition of the desensitizing antigen or antigens, must be based primarily on the clinical history and the area of residence. Most patients could tolerate only very weak dilutions at the beginning of desensitization therapy. Strong dilutions caused exacerbation of the dermatitis. Good or excellent results were obtained with perennial pollen desensitization therapy administered over long periods. In 13 patients good results took four to eight years of desensitization therapy. Fifty required less than two years. Tolerance of the patient for a given dose of antigen should determine the maximum dilution used in therapy.
Topics: Adult; Allergens; Dermatitis; Dermatitis, Atopic; Desensitization, Immunologic; Eczema; Female; Humans; Immunoglobulin E; Male; Pollen; Seasons; Skin Tests
PubMed: 14439675
DOI: No ID Found -
International Archives of Allergy and... 1978Analogous reactions of grass and corn pollen extracts in skin tests on patients suffering from pollinosis might suggest an antigenic relationship between grass and corn...
Analogous reactions of grass and corn pollen extracts in skin tests on patients suffering from pollinosis might suggest an antigenic relationship between grass and corn pollens. This problem was studied using the RAST inhibition test. Tests were performed with cellulose discs labelled with commercial skin test extracts containing grass, rye, wheat, barley, oat and maize pollens. Different mutual inhibitions were measured showing various grades of antigenic relationship. Only grass pollen antigens could strongly inhibit all other antigen-antibody reactions. Thus, we suppose that the investigated grass pollen extract also contains all antigens typical of corn pollen. Therefore, exclusive use of this extract seems to be possible in diagnosis and perhaps therapy of combined grass and corn pollen allergy.
Topics: Cross Reactions; Humans; Poaceae; Pollen; Radioallergosorbent Test; Zea mays
PubMed: 680992
DOI: 10.1159/000232151 -
Molecules (Basel, Switzerland) Jan 2023Bee pollen is frequently characterized as a natural source of bioactive components, such as phenolic compounds, which are responsible for its pharmaceutical potential...
Bee pollen is frequently characterized as a natural source of bioactive components, such as phenolic compounds, which are responsible for its pharmaceutical potential and nutritional properties. In this study, we evaluated the bioactive compound contents of mono- and polyfloral bee pollen samples using spectroscopic and chromatographic methods and established links with their antioxidant and antitumor activity. The findings demonstrated that the botanical origin of bee pollen has a remarkable impact on its phenolic (3-17 mg GAE/g) and flavonoid (0.5-3.2 mg QE/g) contents. Liquid chromatography-mass spectrometry analysis revealed the presence of 35 phenolic and 13 phenylamide compounds in bee pollen, while gas chromatography-mass spectrometry showed its richness in volatiles, such as hydrocarbons, fatty acids, alcohols, ketones, etc. The concentration of bioactive compounds in each sample resulted in a substantial distinction in their antioxidant activity, DPPH (EC: 0.3-0.7 mg/mL), ABTS (0.8-1.3 mM Trolox/mg), and reducing power (0.03-0.05 mg GAE/g), with the most bioactive pollens being the monofloral samples from and . Complementarily, some samples revealed a moderate effect on cervical carcinoma (GI: 495 μg/mL) and breast adenocarcinoma (GI: 734 μg/mL) cell lines. This may be associated with compounds such as quercetin--diglucoside and kaempferol-3--rhamnoside, which are present in pollens from and , respectively. Overall, the results highlighted the potentiality of bee pollen to serve health-promoting formulations in the future.
Topics: Animals; Bees; Antioxidants; Flavonoids; Gas Chromatography-Mass Spectrometry; Mass Spectrometry; Phenols; Pollen
PubMed: 36677892
DOI: 10.3390/molecules28020835 -
The Science of the Total Environment Mar 2024Despite widespread recognition of pollen's potential sensitivity to ultraviolet-B (UV-B) radiation (280-315 nm), there remains ongoing debate surrounding the extent and... (Meta-Analysis)
Meta-Analysis
Despite widespread recognition of pollen's potential sensitivity to ultraviolet-B (UV-B) radiation (280-315 nm), there remains ongoing debate surrounding the extent and mechanisms of this effect. In this study, using published data on pollen germination and tube growth including 377 pair-wise comparisons from 77 species in 30 families, we present the first global quantification of the effects of UV-B radiation on pollen germination and tube growth, along with its underlying mechanisms. Our results showed a substantial reduction in both pollen germination and tube growth in response to UV-B radiation, affecting 90.9 % and 84.2 % of species, respectively. Notably, these reductions exhibited phylogenetic constraints, highlighting the role of evolutionary history in shaping the sensitivity of pollen germination and tube growth to UV-B radiation. A negative correlation between elevation and the sensitivity of pollen tube growth was detected, suggesting that pollens from plants at higher elevations exhibit greater resistance to UV-B radiation. Our investigation also revealed that the effects of UV-B radiation on pollen germination and tube growth were influenced by a range of abiotic and biotic factors. Nevertheless, the intensity and duration of UV-B radiation exposure exhibited the highest explanatory power for the effects on both pollen germination and tube growth. This suggests that the responses of pollens to UV-B radiation are profoundly influenced by its dose, a critical consideration within the context of global change. In conclusion, our study provides valuable insights into the diverse responses of pollen germination and tube growth to UV-B radiation, highlighting the environment and species-dependent nature of pollen's susceptibility to UV-B radiation, with substantial implications for our understanding of the ecological and agricultural consequences of ongoing changes in UV-B radiation.
Topics: Humans; Germination; Phylogeny; Pollen; Plants; Biological Evolution
PubMed: 38224898
DOI: 10.1016/j.scitotenv.2024.170097