Relationships between flowering development of Ulmus pumila and Fraxinus excelsior and their airborne pollen

The flowering patterns of Ulmus pumila and Fraxinus excelsior were studied during the 1990 growing season in order to investigate their pollen dispersion curves. The use of airborne pollen records as predictors of flowering of allergenic trees was evaluated. A sampling method to describe quantitative flowering phenophases was applied. A Burkard trap recorded airborne pollen in the city of Mar del Plata. The phenological sampling method showed that floral phenophase development is not always synchronous between trees. The variability registered was larger for F. excelsior than for U. pumila. A delay between flowering and the airborne pollen recorded was not noticed for Ulmus. The greatest amount of Ulmus pollen came from the local vegetation, mainly from U. pumila. Fraxinus pollen was recorded for a longer period after the F. excelsior flowering season the ended. Fraxinus pollen income came from F. excelsior but also from F. americana and F. excelsior var. aurea that flower later. An immediate decrease in airborne concentration was noticed for both pollen types following rain. When relatively strong rainfall was registered a decrease in the number of open flowers occurred only in F. excelsior.     

Diagnosis of <Emphasis Type="Italic">Chenopodium album</Emphasis> allergy with a cocktail of recombinant allergens as a tool for component-resolved diagnosis

Chenopodium album pollen is one of the main sources of pollen allergy in desert and semi-desert areas and contains three identified allergens, so the aim of this study is comparison of the diagnostic potential of C. album recombinant allergens in an allergenic cocktail and C. album pollen extract. Diagnostic potential of the allergenic cocktail was investigated in 32 individuals using skin prick test and obtained results were compared with the acquired results from C. album pollen extract. Specific IgE reactivity against the pollen extract and allergenic cocktail was determined by ELISA and western blotting tests. Inhibition assays were performed for the allergenic cocktail characterization. The exact sensitization profile of all patients was identified which showed that 72, 81 and 46% of allergic patients had IgE reactivity to rChe a 1, rChe a 2 and rChe a 3, respectively. Almost all of C. album allergic patients (30/32) had specific IgE against the allergenic cocktail. In addition, there was a high correlation between IgE levels against the allergenic cocktail and IgE levels against the pollen extract. The allergenic cocktail was able to completely inhibit IgE binding to natural Che a 1, Che a 2 and Che a 3 in C. album extract. In addition, positive skin test reactions were seen in allergic patients that tested by the allergenic cocktail. The reliable results obtained from this study confirmed that the allergenic cocktail with high diagnostic potential could be replaced with natural C. album allergen extracts in skin prick test and serologic tests.     

Release behavior of small sized daughter allergens from Cryptomeria japonica pollen grains during urban rainfall event

In Japan, Cryptomeria japonica pollen (with diameter ~30 μm) is scattered during each spring season. Daughter allergenic particles, which are smaller in size than their parent pollen grain and are abundant in fine particles (the particle sizes < 1.1 μm, PM_1.1), are released in the atmosphere. The daughter allergenic particles of pollen can be transported in the urban atmosphere for a long period of time after their release. In particular, the daily variation delays in the peaks of allergenic Cry j 1 concentrations compared with the peaks of airborne parent pollen counts were observed in high levels during 1 or 2 sunny days after rainfall. In addition, long range transportation of Asian dusts (ADS) from the East Asian continent was also found during the pollen scattering seasons in Japan. Therefore, the interaction between pollen and air pollutants, including ADS, should be of concern. Thus, in this study, the morphological change of Cryptomeria japonica pollen and the elution behavior of its allergenic contents (Cry j 1) were investigated. Our results confirmed the existence of fine daughter allergen particles, which are clearly differ from the parent pollen grains in size. Fine allergenic particles in atmosphere were increased, while coarse allergenic particles were decreased on sunny days after rainfall. However, the correlation between the mass concentrations of fine particles and mass levels of Cry j 1 in coarse particles (the particle sizes > 7.0 μm) was poor. The possible reason may be pollen burst at high humidity before rainfall. Additionally, Cry j 1 contents were emitted from the so-called Ubisch body, which contains allergenic Cry j 1 abundantly when pollen was in contact with rainfall. In particular, we found that 60% of allergenic Cry j 1 contents released in air polluted rainfall contained Ca²⁺ ion derived from road dust and ADS. Therefore, rainfall should be a main factor to induce transition of pollen allergenic contents to fine particles. In conclusion, allergenic particles which are small sized and translated into fine particles by rainfall can be inhaled into the lower respiratory tract and contribute to the hypersensitivity of asthma.     

Detection and release of allergenic proteins in Parietaria judaica pollen grains

Summary. Rapid diffusion of allergenic proteins in isotonic media has been demonstrated for different pollen grains. Upon contact with stigmatic secretion or with the mucosa of sensitive individuals, pollen grains absorb water and release soluble low-molecular-weight proteins, these proteins enter in the secretory pathway in order to arrive at the cell surface. In this study we located allergenic proteins in mature and hydrated-activated pollen grains of Parietaria judaica L. (Urticaceae) and studied the diffusion of these proteins during the first 20 min of the hydration and activation processes. A combination of transmission electron microscopy and immunocytochemical methods was used to locate these proteins in mature pollen and in pollen grains after different periods of hydration and activation processes. Activated proteins reacting with antibodies in human serum from allergic patients were found in the cytoplasm, wall, and exudates from the pollen grains. The allergenic component of these pollen grains changes according to the pollen state; the presence of these proteins in the exine, the cytoplasm, and especially in the intine and in the material exuded from the pollen grains, is significant in the hydrated-activated studied times, whereas this presence is not significant in mature pollen grains. The rapid activation and release of allergenic proteins of P. judaica pollen appears to be the main cause of the allergenic activity of these pollen grains. Correspondence and reprints: Department of Plant Biology, Faculty of Biology, University of León, Campus de Vegazana, 24071 León, Spain.     

Modern pollen–vegetation relationships along transects on the Whangapoua Estuary, Great Barrier Island, northern New Zealand

Aims To quantify pollen–vegetation relationships from saline to freshwater in an estuarine gradient from surface samples of the modern pollen rain, to allow more accurate interpretations of the stratigraphic palynological record. Location Whangapoua Estuary, Great Barrier Island, northern New Zealand. Methods Six transects were laid out along a vegetation sequence running from estuarine mud to freshwater swamp. Along these transect lines, 108 plots were sampled for vegetation and surface sediments from wet sand, mud, plant litter or moss (sand and mud sites are inundated by most tides, other sites less frequently). All sediment samples were analysed for pollen. The relationships between plant species frequency and pollen representation were examined at a community scale using twinspan and ordination analyses, and for individual species using fidelity and dispersibility indices, regression and box‐plot analyses. Results The quantitative relationships between source taxon vegetation frequency and its pollen representation varied between species due to differential pollen production and dispersal. twinspan of the surface pollen samples suggests five vegetation types: (A) mangrove (Avicennia marina); (C) Leptocarpus similis salt meadow; (D) Baumea sedges; (E) Leptospermum shrubland; and (F) Typha/Cordyline swamp forest. The (B) Juncus kraussii community is not represented palynologically owing to the destruction of its delicate pollen grains during acetolysis of samples. Detrended correspondence analysis places these communities on an estuarine‐to‐freshwater gradient. However, pollen assemblages at the seaward end of the salinity gradient are less clearly representative of the associated vegetation than those at the landward end, probably because the open vegetation at the former allows the influx of wind‐ and water‐dispersed pollen from surrounding vegetation. Main conclusions The vegetation pattern (zonation) at Whangapoua is reflected in the pollen rain. When the long‐distance and over‐represented pollen types are excluded, five out of six of the broad vegetation communities can be identified by their pollen spectra. Species with high fidelity and low‐to‐moderate dispersibility indices can be used to identify the vegetation types in the sedimentary sequences. The more open vegetation types at the ‘marine end’ of the sequence tend to be ‘overwhelmed’ by regional pollen, but the nature of the sediments and the presence of discriminatory species (e.g. A. marina, Plagianthus divaricatus, Cordyline australis), even in small amounts, will allow correct identification of the local vegetation represented in sedimentary palynological sequences. A box‐plot analysis indicates that the pollen and spore types A. marina (mangroves), Sarcocornia quinqueflora (salt meadow), P. divaricatus (sedges), Gleichenia (shrubland) and C. australis (swamp forest) are highly discriminatory in relation to vegetation type. These discriminatory palynomorphs help with the interpretation of stratigraphic pollen studies. However, salt marsh vegetation communities in the sediments must be interpreted with caution as the marine sediments are easily affected by erosion, bioturbation and tidal inundation effects.     

Airborne pollen from allergenic herbaceous plants in urban and rural areas of Western Pomerania,NW Poland

This paper presents the course of the pollen season of selected allergenic taxa (Rumex spp., Plantago spp., Urtica spp. and Chenopodiaceae) in two towns with different degrees of urbanisation (urban, the city Szczecin, and rural, the village Gudowo in Western Pomerania, northwest Poland). The study was conducted in the years 2012–2014 with the volumetric method. The pollen of allergenic herbaceous plants was present in the air from early May until the end of September. From among the taxa studied, the genus Rumex is characterised by the longest pollination period, while the genus Urtica by the shortest. The highest percentage contribution of pollen grains to the total pollen count in the air reaching over 90% is from nettle. The pollen seasons determined for the majority of taxa are longer in the city, however the mean pollen grain counts in the air are higher for the rural area.     

Pollinosis in trentino (Northern Italy). Aerobiological and clinical research

Summary A study to evaluate and define the atmospheric pollen concentration in Trentino was carried out through the aerobiologic sampling in three localities chosen according to their different climatic conditions.1375 patients with pollinosis living in Trentino were studied retrospectively over the period ranging from 1986 to 1988 and selected according to the area they came from.Results have proved that the most allergenic pollen types are the following: Poaceae, Urticaceae (Parietaria), Compositae (Artemisia) and the tree pollen of Betulaceae and Corylaceae (Alnus, Betula, Corylus), and that pollinosis caused by such pollen, types has different features and frequencies according to the different localities.As far as symptoms are concerned, our data shows that rhinoconjuntivitis is more frequent in those patients who are allergic toParietaria while asthma results being more frequent in patients who are allergic to tree pollen.     

Seed hairs of poplar trees as natural airborne pollen trap for allergenic pollen grains

The present article deals with the efficacy of seed hairs of poplar trees (Populus spp.) as a potent natural airborne pollen trap. Different species of Populus are commonly found planted along the streets in the cities of North China. The seed hairs and pericarp of poplar trees were collected from the trees and on the ground in Beijing Botanical Garden of Chinese Academy of Sciences and around Miyun Reservoir during May 2005 for pollen analysis. Different pollen spectra are recorded from different samples and are characterised by dominant occurrence of pollen grains of arboreal and anemophilous plants. In addition, pollen grains of non‐arboreal plants including grasses are also found trapped. Among the 46 trapped pollen grains, 26 are known to be allergenic. This study suggests that poplar seed hairs possibly make people feel uncomfortable due to the presence of allergenic pollen trapped in the hairs.     

Allergenicity of Acroptilon repens and Juglans regia pollen in rats

Pollen proteins that are located in the cytoplasm or on the surface of the exine can function as allergens and evoke immune system responses in sensitive patients, leading to allergic rhinitis and asthma. In this research, the pollen allergenicity and ability to induce IgE response of the pollen of two plant species were studied in rats. Acroptilon repens is an herbaceous, invasive plant with entomophilous pollen, while Juglans regia which is a tree crop produces anemophilous pollen. Immunoblot analysis using sera of sensitised rats revealed IgE reactivity to three protein bands including the 70, 41 and 25.12 kDa bands present in the A. repens pollen extract, while only one single immunogenic band of 11 kDa was detected in J. regia pollen extract. Both pollen extracts increased the eosinophil content and caused some clinical signs of allergy in treated rats. The results showed that both entomophilous and anemophilous pollen can be allergenic.     

New biomolecular tools for aerobiological monitoring: Identification of major allergenic Poaceae species through fast real‐time PCR

Grasses (Poaceae) are very common plants, which are widespread in all environments and urban areas. Despite their economical importance, they can represent a problem to humans due to their abundant production of allergenic pollen. Detailed information about the pollen season for these species is needed in order to plan adequate therapies and to warn allergic people about the risks they take in certain areas at certain moments. Moreover, precise identification of the causative species and their allergens is necessary when the patient is treated with allergen‐specific immunotherapy. The intrafamily morphological similarity of grass pollen grains makes it impossible to distinguish which particular species is present in the atmosphere at a given moment. This study aimed at developing new biomolecular tools to analyze aerobiological samples and identifying major allergenic Poaceae taxa at subfamily or species level, exploiting fast real‐time PCR. Protocols were tested for DNA extraction from pollen sampled with volumetric and gravimetric methods. A fragment of the matK plastidial gene was amplified and sequenced in Poaceae species known to have high allergological impact. Species‐ and subfamily‐specific primer–probe systems were designed and tested in fast real‐time PCRs to evaluate the presence of these taxa in aerobiological pollen samples. Species‐specific systems were obtained for four of five studied species. A primer–probe set was also proposed for the detection of Pooideae (a grass subfamily that includes also major cereal grains) in aerobiological samples, as this subfamily includes species carrying both grass allergens from groups 1 and 5. These, among the 11 groups in which grass pollen allergens are classified, are considered responsible for the most frequent and severe symptoms.     

Air pollution exacerbates effect of allergenic pollen proteins of Cassia siamea: a preliminary report

Pollinosis caused by several allergenic proteins in pollen grains has been a major problem of healthcare in most parts of the world. Environmental factors such as air pollution are known to alter the release of allergenic pollen proteins from a variety of the plant species. Cassia siamea is commonly planted along roadsides and in industrialised areas in many parts of India. The present study reports the findings of animal experiments demonstrating the effect of air pollution on the allergenicity of Cassia siamea pollen proteins. Total white blood cell (WBC) count and lymphocyte count were significantly higher in animals that received protein extract of pollen collected from a polluted site compared to those that received protein extract of pollen collected from a non-polluted site. This was concomitant with increased production of IgE antibodies; followed by marked degranulation of mast cell leading to heighten type I hypersensitivity in these animals. These results are important for the development of a consensus linking ever-increasing pollution due to industrialisation and an increase in associated pollinosis.     

Correlation between aerobiological and phytogeographical investigations in the Florence area

Summary The aim of our research work was to evaluate the results from our pollen count (p.c.) carried out at the Allergological Centre of Nuovo Osp. San Giovanni di Dio in Florence, in the light of orogeographical, phytogeographical and meteorological data. The highest p.c. was yielded by Graminaceae which appear in small quantities early in the year but increase considereably starting from April. Oleaceae too showed high pollen concentration but over a shorter lenght of time. The p.c. for Compositae and Urticaceae was lower. It should be noted that Cupressaceae yielded constantly high p.c. in February–March. Investigations on the allergenic flora of the surroundings were carried out concentrically in order to find out the closest and the farthest sources of pollen production. The species investigated come under 7 types of vegetation: xerophilous woods, mesophilous woods, conifers woods, parks and gardens, rural areas, meadows, border areas-weeds. A phytosociological study of the types of vegetation has made it possible to evaluate the single species quantitatively. The different sources of pollen production can be spotted by mapping these types of vegetation. The seasonal characterization of pollen production is better defined by means of periodical phenological checking of the existing allergenic flora along carefully planned routes through the areas next to the sampling station.      

Pollen distribution at elevations above 1000 m inSwitzerland

In Switzerland the concentration of allergenic pollendecreases with increasing elevation of the samplingsite of the Swiss pollen measuring network. The aim ofthis study was, to compare the pollen concentrationsof five different localities in the Swiss Alps and inthe Jura mountains, to get an idea of the differencesin the pollen abundance in altitudes above 1000 m. Theinvestigated localities are: La Chaux-de-Fonds(1040 m), Wiesen (1420 m), Davos (1600 m), Samedan(1705 m) and Gütsch (2287 m). These pollen sumswere compared to the Swiss plateau (Basel 273 m).Basel, La Chaux-de-Fonds and Wiesen show clearlyhigher pollen values than Davos, Samedan andGütsch. Pollen concentrations of Corylus,Alnus glutinosa-type and Fraxinus arereduced with increasing altitude and are only a smallproblem for allergies above 1000 m. Betulapollen are also reduced in the higher localities, butthere still occur many days with high pollenconcentrations. Especially Betula pollen frommedium range transport can play an important role forallergies in higher localities. The total grass pollensum does not decrease up to an altitude of 1500 m. Thegrass pollen concentration depends more on factorslike composition of the local grassland, land use andwind situation.Pollen concentrations at higher elevations isinfluenced by the local vegetation, a reduced pollenproduction, land use, topography, exposition, windvelocity and wind direction. These factors modify thepollen concentration considerably. Due to the complextopography of the Prealps and Alps, it is thereforenot possible to propose a general rule of pollenreduction with increasing altitude.     

Reliability of pollen ratios for environmental reconstructions on the Tibetan Plateau

Aim Pollen ratios are widely used to gain palaeovegetation and palaeoclimatic information from fossil pollen spectra, although their applicability has seldom been tested with modern pollen data. I used a data set of 113 lake‐surface sediments from the eastern Tibetan Plateau to test the reliability of several pollen ratios. Location The lake‐surface pollen spectra cover a wide range of vegetation types (temperate desert, temperate steppe, alpine desert, alpine steppe, high‐alpine meadow, sub‐alpine shrub, coniferous and mixed forest) and climatic conditions (mean July temperature, T_July: 4.0–17.4°C; mean annual precipitation, P_ann: 104–670 mm). Methods Lake‐surface sediments were analysed palynologically, and several pollen ratios were calculated. These ratios were interpreted with respect to vegetation and climatic conditions. Results The arboreal pollen sum (AP) was highest in samples from forested areas and was significantly correlated with P_ann (r² = 0.44). In non‐forested areas, samples from large lakes and from lakes surrounded by sparse vegetation had increased AP values, suggesting that AP is a useful vegetation density indicator. Artemisia/Chenopodiaceae (A/C) ratios were lowest in desert areas and were positively correlated with P_ann (r² = 0.25). The aridity pollen index was inappropriate for inferring (palaeo‐)climatic information from samples on the eastern Tibetan Plateau as it had no significant correlation with the environmental factors. Artemisia/Cyperaceae (A/Cy) ratios had a significant correlation with T_July (r² = 0.23), but only a weak correlation with P_ann, which indicates that the A/Cy ratio is applicable as a temperature indicator. Furthermore, it is a valuable tool for the differentiation of high‐alpine meadow from steppe vegetation. Main conclusions AP sum, A/C ratio and A/Cy ratio are useful tools for qualitative and semi‐quantitative palaeoenvironmental reconstruction on the Tibetan Plateau; however, the results obtained should not be interpreted quantitatively.     

Herb pollen representation in surface moss samples from mown meadows and pastures in western Norway

Grazed and mown vegetation types in western Norway were investigated with the aim of describing their modern pollen/vegetation relationships as an aid to the interpretation of fossil pollen diagrams. Pollen surface samples and vegetation data were obtained from 186 square metre plots within 39 different sites of 10×10 m. Scatter plots that show the relationship between pollen percentages and vegetation percentages are presented forTrifolium pratense-type,Trifolium rcpens-type,Lotus, Campanula-type,Succisa, Ranunculus acris-type,Cirsium-type, Asteraceae Cichorioideae,Achillea-type,Potentilla-type, Apiaceae,Rumex sect.Acetosa, Galium-type, Cyperaceae,Calluna, Plantago lanceolata and Poaceae. Pollen representation factors relative to Poaceae (R_rel) are calculated for 54 pollen taxa. Differences in the values from different geographical areas were found in the case of some taxa, due to either different genera or species being included in the pollen taxa and/or to the different representation of high pollen producers in the different regional vegetation types. Background pollen influences the estimates for taxa such asR. sect.Acetosa, P. lanceolata, Poaceae, Cyperaceae, andCalluna, and an extended R-value (ERV) model was used to investigate the magnitude of this pollen component. Groups of roughly similar pollen representation were identified and factors to convert pollen percentages to vegetation abundances are suggested.     

Purification and characterization of allergens from Xanthium strumarium pollen

The allergenic components present in whole pollen extract of Xanthium strumarium were isolated by sequential ammonium sulphate precipitation, DEAE Sephadex A50 chromatography and gel filtration. The techniques of RAST inhibition and skin test were utilized to check the allergenicity of fractionated proteins revealing the presence of Xan Ib and Xan VIa as the important allergenic componenets. Xan Ib was found to be devoid of carbohydrate and had a molecular weight of 103 000 daltons. Xan VIa was a glycoprotein of molecular weight 17 000 daltons. The carbohydrate moiety of Xan Vla was found to be associated with allergenicity. The characteristic pattern of whole pollen extract on CIE and TLIEF showed 36 and 21 protein bands, respectively. The use of FPLC in isolation of partially purified allergens from Xanthium is discussed.     

Identification of methionine synthase (Sal k 3), as a novel allergen of <Emphasis Type="Italic">Salsola kali</Emphasis> pollen

Salsola kali pollen is a common cause of pollinosis during summer and early fall in desert and semi-desert regions. The aim of this study was the identification and characterization of Sal k 3, a new allergen from S. kali pollen. S. kali pollen extract was fractionated by SDS-PAGE and the allergenic profile was determined by IgE-immunoblotting using twelve S. kali allergic patients. Protein identification was carried out by the means of mass spectrometry. Using degenerated primers, two DNA fragments encoding N- and C-terminal domain of Sal k 3 were amplified by PCR, then cloned into the PTZ57R/T vector and sequenced. The open reading frame of Sal k 3 fragments were subcloned in the pET-32b(+) vector, expressed in E. coli, and purified by Ni²⁺ affinity chromatography. The IgE-binding capacity of rSal k 3 fragments was then studied by IgE-immunoblotting, inhibition assays, and skin prick tests. A 45-kDa allergen was identified as a fragment of the cobalamin-independent methionine synthase (MetE) by mass spectrometry and was detected in the sera of 8/12 (66.6%) of S. kali allergic patients. Moreover, inhibition assays demonstrated that the purified rSal k 3 fragments were similar to their counterparts in the crude extract. Sal k 3 represents a new allergen of S. kali pollen and seems to be an important allergenic compound in S. kali pollen.     

Risk of pollen allergy in Nerja (southern Spain): a pollen calendar

An aeropalynological study was carried out in the atmosphere of the city of Nerja (southern Spain) during a period of 4 years (2000–2003), using a Hirst type volumetric pollen trap. An annual pollen index of 59,750 grains, on average, was obtained with 80–85% of the total pollen recorded from February to May, with Pinus, Olea, Urticaceae, Cupressaceae, Quercus and Poaceae being the principal pollen producers in abundance order. A total of 29 pollen types that reached a 10-day mean equal to or greater than 1 grain of pollen per m³ of air is reflected in a pollen calendar. The results were compared with those obtained for nearby localities and a correlation analysis was made between the daily fluctuations of the main pollen types and total pollen, and meteorological parameters (temperature, rainfall and hours of sun). The daily, monthly and annual values reached by the most important pollen types from an allergenic point of view (Olea, Urticaceae and Poaceae) confirms Nerja as a high-risk locality for the residents and the numerous tourists who visit the area.     

Coastal dune vegetation and pollen representation in south Buenos Aires Province, Argentina

Aim To establish the relationship between coastal dune vegetation and its pollen representation as an aid to interpret Holocene vegetation dynamics and environmental changes from pollen assemblages. Location The study area is situated on the temperate Atlantic coast of south Buenos Aires Province, Argentina (c. 39° S and 61°20′ W). Methods The vegetation of the active dune area adjacent to the beach was described on the basis of its floristic composition from 25 plots. Classification of the vegetation into distinct zones was carried out by cluster analysis. Surface samples were collected from each vegetation stand and analysed for their pollen composition. Pollen percentage data were analysed using principal components analysis in order to investigate the degree to which the different vegetation units can be distinguished by their pollen spectra. Pollen–vegetation relationships for selected taxa were explored using simple scatter plots and indices of association, under‐ and over‐representation. Indices of floristic diversity and palynological richness were used to assess the representation of the vegetation in the pollen spectra. Results and conclusions Five vegetation zones are defined on the basis of species composition and their quantitative variation: back shore, mobile dunes, slacks, semi‐fixed and fixed dunes. Pollen assemblages from back shore, mobile dunes and slacks are clearly differentiated from semi‐fixed and fixed dunes. Pollen assemblages differ considerably from the associated vegetation composition. Major discrepancies are caused by large differences in pollen and vegetation proportion of Hyalis argentea and Discaria americana. There is a considerable proportion of non‐local pollen in every spectrum. Pollen representation in the coastal dunes at Monte Hermoso is influenced by differences in pollen production, dispersal and preservation of individual taxa as well as by the spatial distribution of the vegetation, the topography of the dune system and the wind pattern. The pollen–vegetation relationship established in this study has important implication for understanding and interpreting fossil pollen records from coastal dune environments.     

Allergenic and antigenic proteins released in the apertural sporoderm during the activation process in grass pollen grains

A combination of transmission electron microscopy with immunocytochemical methods was used to localize antigenic and allergenic proteins during the maturation and activation processes of Poaceae pollen grains. The intine undergoes a series of modifications that play a decisive role in these processes. Allergenic and antigenic proteins were detected particularly in the intine of activated in vitro grass pollen grains. Labelling of antigenic proteins was more abundant and less specific than that of allergenic proteins. At the time of hydration, the operculum was lifted up, the intine was swollen and labelling of allergenic proteins appeared highly localized in the Zwischenkörper. No significant labelling was observed when the Zwischenkörper gelatinized. Immunolocalization of allergenic proteins in the activated Zwischenkörper indicated the presence of proteins related to activation of the pollen grains. This confirms that the intine function is involved in the processes of pollen tube formation and fertilization, and also suggests the possible mechanism activated in the pollen grains when allergenic proteins reach the mucosa of sensitive subjects.