Dry Pollen Research Articles

Walnut Staminate Flowers Can Be Explored as a Supplementary Plant Oil Source

AbstractFossil fuel is currently the major energy source driving global socio‐economy, but its stock is being heavily depleted due to increasing anthropogenic activities worldwide. There are also concerns regarding the burning of fossil fuels, which contributes to global climate warming and air pollution. As such, the development of biodiesel as a non‐toxic, biodegradable, and renewable alternative energy source using oil crops such as soybean and rapeseed has quickly emerged in the West countries. However, the production of oil crops in China is far from sufficient to meet the demands of the country's population of 1.3 billion, and increasing oil crop production is inhibited by a severe shortage of agricultural land, which currently averages 0.2 acre per person and, as such, is less than half the world average. The current national policy in China regarding land use is more towards revering cultivated lands in ravins and hills to forestry, which presents an ideal opportunity to further develop plantations of walnut (Juglans regia L.) trees, a plant that is tolerant to drought and infertile soils and has a high oil content. Study in this paper shows that one ament of walnut staminate flowers produces about 0.168 g dry pollen, and the dry pollen contained 49.67% oil. Based on this discovery, oil yield obtained from staminate flowers is estimated to reach 6.95% of that from walnut nuts. Thus walnut staminate flower is suggested to explore as supplementary plant oil source, and has a great opportunity to utilize as a biodiesel feedstock.(Managing editor: Wei Wang)

Development and reproduction of Adalia bipunctata (Coleoptera: Coccinellidae) on eggs of Ephestia kuehniella (Lepidoptera: Phycitidae) and pollen

Due to growing criticism over the use of non-indigenous coccinellids, the two-spot ladybird, Adalia bipunctata (L.), has enjoyed increasing attention for aphid biocontrol in Europe. In the current study, eggs of the Mediterranean flour moth, Ephestia kuehniella Zeller, whether or not supplemented with bee pollen, were evaluated as a factitious food for larvae and adults of A. bipunctata. The predator showed slower larval development and lower survival when reared on live pea aphids, Acyrthosiphon pisum (Harris), than on E. kuehniella eggs. Survival on gamma-irradiated eggs of E. kuehniella was superior to that on frozen flour moth eggs, but other developmental characteristics were similar. Adults of A. bipunctata reared on Ac. pisum were only half as fecund as those offered irradiated or frozen E. kuehniella eggs, but egg hatch was markedly better on live aphids than on flour moth eggs (61 versus 20-27%, respectively). However, when a diet of flour moth eggs was supplemented with frozen moist bee pollen, egg hatch of A. bipunctata was equally as good as on live aphids. Supplementing flour moth eggs with dry pollen did not yield satisfactory results. Only 10% of larvae reached adulthood on moist bee pollen alone and resulting adults weighed less than half as much as those obtained on flour moth eggs. Our findings indicate that A. bipunctata is able to compensate for a suboptimal diet of animal prey by supplementary feeding on flower pollen. It is concluded that pollinivory may be a crucial trait for both the rearing of this natural enemy and its use in biological control programmes.

Diversity and feeding behaviour of insects visiting Brachiaria ruziziensis (Poaceae)

The diversity of visitors to flowers of the grass Brachiaria ruziziensis R. Germ and Evrard is very low in Ngaoundere, Cameroon. Bees (Hymenoptera) and syrphids (Diptera) were observed gathering pollen, and each insect group had its own strategy depending on the prevailing environmental conditions. Syrphids are early-morning flower visitors and take time to feed on wet pollen. They visit flowers from 0630 h when the relative humidity is higher than 80% and temperature lower than 25°C Bees gather dry pollen from 0930 h when the relative humidity is 30°C, and carry it to the nests for feeding.

Ultrastructure and diversity of recent and fossil zona-aperturate pollen grains

A survey of recent and fossil zona-aperturate pollen grains within the angiosperms was undertaken. Zona-aperturate pollen (with complete ring-like apertures) has been evolved independently in several genera of basal angiosperm families (Nymphaeaceae, Eupomatiaceae, Annonaceae, Monimiaceae, Atherospermataceae) and monocots (Araceae, Iridaceae, Laxmanniaceae, Arecaceae, and Rapateaceae). The special case of the eudicot Limnanthes (Limnanthaceae) is discussed. New examples of recent and fossil fully zonate pollen are presented; a noteworthy new example are Scrophulariaceae, with Pedicularis; our fossil examples show affinities either to Nymphaeaceae, or Araceae, or Iridaceae, or cannot be related to an extant taxon. The zona-aperturate pollen grains differ in ornamentation and stratification mostly in the respect of the aperture areas, but sometimes also outside the aperture. The question of polarity is settled only for some taxa because of the frequent lack of tetrad observations. A ring-like aperture may divide the pollen grains in symmetric halves, or if running asymmetrically, divides the pollen grain in two more or less unequal halves; the presence of clearly unequal halves gives a strong argument to assume an equatorial ring in such cases where tetrad configurations were not available. The zona-aperturate condition may be a functional benefit in wet environments: while in dry pollen the apertural ring is completely closed, in wet or very moist realm it expands greatly, and the pollen tube can be formed quickly and everywhere in this area.

Molecular characterization of polygalacturonases as grass pollen-specific marker allergens: expulsion from pollen via submicronic respirable particles.

Grass pollen belong to the most important allergen sources involved in the elicitation of allergic asthma. We have isolated cDNAs coding for Bermuda grass (Cynodon dactylon) and timothy grass (Phleum pratense) pollen allergens, belonging to a family of pectin-degrading enzymes (i.e., polygalacturonases). The corresponding allergens, termed Cyn d 13 and Phl p 13, represent glycoproteins of approximately 42 kDa and isoelectric points of 7.5. rPhl p 13 was expressed in Escherichia coli and purified to homogeneity. Immunogold electron microscopy using rabbit anti-rPhl p 13 Abs demonstrated that in dry pollen group 13, allergens represent primarily intracellular proteins, whereas exposure of pollen to rainwater caused a massive release of cytoplasmic material containing submicronic particles of respirable size, which were coated with group 13 allergens. The latter may explain respiratory sensitization to group 13 allergens and represents a possible pathomechanism in the induction of asthma attacks after heavy rainfalls. rPhl p 13 was recognized by 36% of grass pollen allergic patients, showed IgE binding capacity comparable to natural Phl p 13, and induced specific and dose-dependent basophil histamine release. Epitope mapping studies localized major IgE epitopes to the C terminus of the molecule outside the highly conserved functional polygalacturonase domains. The latter result explains why rPhl p 13 contains grass pollen-specific IgE epitopes and may be used to diagnose genuine sensitization to grass pollen. Our finding that rabbit anti-rPhl p 13 Abs blocked patients' IgE binding to the allergen suggests that rPhl p 13 may be used for immunotherapy of sensitized patients.

In vivo hydration and pollen germination in Crocus vernus ssp. vernus as a function of humidity

The hydration and germination of Crocus vernus ssp. vernus pollen were examined when placing pollen on the stigma papillae under 10% to 100% relative humidity (RH). Following adhesion of the pollenkitt to the papilla, the pollen grain hydrates and swells up to emit a pollen tube, and its adjoined pollen grains may bypass contact with the papilla for hydrating and germinating. The hydration capacity increases in parallel to both the pollen dryness and the RH increase, but dry pollen does not reach full hydration. Without being placed on the stigma, dry pollen shows a moderate capacity to absorb water from the moist air, and slightly dehydrated pollen tends to lose water. Germination on the stigma shows the main increment in the interval of 20-40% RH, with a linear increase from 35.2% to 82.5%. Under 20% RH, the germination is low and inhomogeneous, while at over 40% RH it stabilizes, until it increases again at over 70% RH, with slightly different peaks for dry (86.3%) and undehydrated (94%) pollen at 90-1...

Complex hydroseral vegetation succession and ‘dryland’ pollen signals: a case study from northwest Scotland

Pollen assemblages from sediment systems developed in response to changing sea level provide potentially valuable archives of local landscape dynamics in the coastal zone. Changes in wetland vegetation structure associated with the successional transition from saline to freshwater communities, and subsequent terrestrialization, however, will have marked effects on the palynological signal from surrounding dry land communities by altering the taphonomic properties of the pollen-recruiting system. We present data from one such system, a coastal wetland on the Coigach Peninsula in northwest Scotland, focusing here on reconstructing the hydroseral processes of wetland development, and how they affect the interpretation of the dry pollen signal. This contribution highlights the often-unacknowledged ambiguities inherent in reconstructing past environments from complex sedimentary systems, and outlines strategies for clarifying them.

Chemosensory control of pollen ingestion in the hoverfly Eristalis tenax by labellar taste hairs.

The labellar gustatory system of the dronefly Eristalis tenax L. (Syrphidae; Diptera) that enables the fly to discriminate between pollen and nectar is investigated, and the triggering of pollen ingestion is examined. In behavioural preference tests, exhaustively extracted pollen of the sunflower Helianthus annuus is consumed in smaller amounts than untreated pollen, indicating that water-soluble substances are important for acceptance. Dry pollen is preferred over moist pollen in which the grains stick together, suggesting that mechanical properties of the pollen also play a role in its sensory assessment. Electrophysiological studies of the labellar taste hairs reveal that aqueous extracts of pollen (2% w/v) stimulate the salt receptor cell, but not the sugar receptor cell. The response of the water receptor cell remains the same as to pure water (or standard electrolyte, 10 mmol.l-1 KCl). Of the 20 amino acids tested, the salt cell is sensitive only to proline in a submillimolar range. Behavioural experiments support the electrophysiological findings. When KCl is applied at concentrations eliciting salt-cell spike frequencies equal to those produced by pollen extract (which is often accepted), the water receptor cell is inhibited and a pronounced rejection behaviour occurs. This rejection of concentrated salt solution in Eristalis is therefore mainly mediated by the inhibition of the water cell.

Dioecy and wind pollination in Pernettya rigida (Ericaceae) of the Juan Fernández Islands

Abstract Pernettya rigida is endemic to the Juan Fernandez archipelago. Although all flowers are complete, with seemingly fertile stamens and pistils, differences in fruit production and detailed field, anatomical, and morphological studies indicate they are functionally unisexual, and the species is consequently dioecious. A comparison of 15 features demonstrated significant differences between the sexes. The populational sex ratio is 1:1. Nectaries located between the filaments produce small amounts of floral nectar with similar sugar composition in both sexes. There are x=33,357 (or x=133,429) pollen tetrads (or pollen grains)/male flower and x=109 ovules/female flower. No tetrads in either hand self-pollinated or open pollinated male flowers showed any pollen germination. Tetrads on open- and hand-pollinated female flowers germinate. Female flowers do not show autogamy or apomixis. During more than 80 hours of field observation, we recorded only seven floral visitors (representing three insect species). In spite of this, open-pollinated female flowers have abundant fruit and seed-set. Thus, we conclude that pollen is transferred abiotically and the ever-present wind over the exposed ridges of the islands is the likely dispersal agent. A number of anemophilous features, such as dry pollen and exposed habitat, support this conclusion. Thus, dioecy and anemophily have evolved independently, in situ , in this species in this remote locality. Preservation of habitat and elimination of competitive invasives are the primary conservation challenges.

Dioecy and wind pollination in Pernettya rigida (Ericaceae) of the Juan Fernández Islands

Pernettya rigida is endemic to the Juan Fernández archipelago. Although all flowers are complete, with seemingly fertile stamens and pistils, differences in fruit production and detailed field, anatomical, and morphological studies indicate they are functionally unisexual, and the species is consequently dioecious. A comparison of 15 features demonstrated significant differences between the sexes. The populational sex ratio is 1:1. Nectaries located between the filaments produce small amounts of floral nectar with similar sugar composition in both sexes. There are x=33,357 (or x=133,429) pollen tetrads (or pollen grains)/male flower and x=109 ovules/female flower. No tetrads in either hand self-pollinated or open pollinated male flowers showed any pollen germination. Tetrads on open- and hand-pollinated female flowers germinate. Female flowers do not show autogamy or apomixis. During more than 80 hours of field observation, we recorded only seven floral visitors (representing three insect species). In spite of this, open-pollinated female flowers have abundant fruit and seed-set. Thus, we conclude that pollen is transferred abiotically and the ever-present wind over the exposed ridges of the islands is the likely dispersal agent. A number of anemophilous features, such as dry pollen and exposed habitat, support this conclusion. Thus, dioecy and anemophily have evolved independently, in situ, in this species in this remote locality. Preservation of habitat and elimination of competitive invasives are the primary conservation challenges.

Immunogold Electron Microscopic Localization of the Cross–Reactive Two–EF–Hand Calcium–Binding Birch Pollen Allergen Bet v 4 in Dry and Rehydrated Birch Pollen

Background: Recently, a novel family of low–molecular–weight (8–9 kD), two–EF–hand calcium–binding proteins has been described as allergens in plant pollens. Approximately 10% of pollen–allergic patients have IgE antibodies which cross–react with the two–EF–hand allergens in tree, grass and weed pollens. The aim of the present study was to localize Bet v 4, the two–EF–hand allergen from birch, in mature, dry pollen and to study the release of this allergen after hydration of the pollen by immunogold electron microscopy. Methods: Using completely anhydrous fixation techniques in combination with immunogold electron microscopy, we localized Bet v 4 and, for control purposes, the major birch pollen allergen Bet v 1, in dry birch pollen as well as in pollen grains after different periods of hydration. Parallel with these morphological studies, we monitored the release of Bet v 4 and Bet v 1 into aqueous supernatants of hydrated birch pollen grains by immunoblotting. Results: Bet v 4 was found in the electron–dense cytosol, in particular between the vesicles and cisternae of the endoplasmic reticulum, inside mitochondria and in the vegetative as well as in the generative nucleus. Bet v 1 was localized in similar cellular compartments except for the mitochondria. After 30 s to 1 min of hydration, Bet v 4 migrated into the pollen exine and into the aqueous supernatants. Bet v 1 also moved out of the pollen grain, though not as quickly as Bet v 4. Conclusion: Bet v 4 represents an intracellular pollen protein which, following hydration of pollen grains, rapidly migrates to the pollen surface (exine) and is washed out. This behavior explains how Bet v 4, being primarily an intracellular pollen protein, becomes available to sensitize patients.

Effects of relative humidity and temperature stress on pollen viability of Cistus incanus and Myrtus communis

Cistus incanus and Myrtus communis are two species commonly found in Mediterranean shrublands, flowering respectively in spring and summer. Pollen of single flowers of C. incanus is available for dispersal for 8-10 hours, during which time viability decreases from 91% to 61%. Field measurements of the variation in the percent pollen viability during the anthesis of single flowers of M. communis shows that, immediately after anthesis, pollen viability is very high; by the end of the first day it significantly declines and 36 hours after anthesis almost all grains are unviable. Experiments carried out under controlled environment showed that, in C. incanus, the greatest loss of viability occurs at 100% humidity and high temperatures, while under dry conditions pollen viability remains high throughout a wide temperature range. Similarly, pollen viability of M. communis remains high for several hours at high temperature and dry conditions, while it rapidly decreases at high humidity. In conclusion, the temperature experiments indicate that in C. incanus and M. communis, pollen viability does not appear to be drastically reduced if the relative humidity of the environment is low. Therefore, humidity is a far more important factor determining pollen viability loss in both species.

Imbibitional leakage from anhydrobiotes revisited

ABSTRACTDry desiccation‐tolerant organ(ism)s leak cellular solutes when placed in water. Elevated temperatures at imbibition and elevated initial moisture contents reduce the leakage and promote growth. We have re‐examined the effects of imbibitional stress imposed on cattail (Typha latifolia L.) pollen as a model anhydrobiotic system. A nitroxide spin probe technique and electron microscopy were used, allowing study of the permeability of the plasma membrane together with its visual intactness. Imbibitional leakage can be transient, or prolonged when associated with membrane damage. During the first 15 s of rehydration in medium, plasma membranes of pre‐humidified pollen were highly permeable but became less permeable thereafter. The resulting transient leakage may affect vigour as measured by the rate of fresh weight increase, but did not reduce germination. A permanent, high permeability was observed when dry pollen was plunged into medium at low temperatures. This led to cell death and is associated with a phase change of the membranes from gel to liquid crystalline during imbibition. Freeze‐fracture images indicate that the damage to plasma membranes is mechanically imposed by the pressure of the penetrating water rather than occurring structurally by a phase separation of membrane components. We suggest that a high rigidity of the plasma membranes in the gel phase at imbibition underlies imbibitional damage.

Amplification of RAPD markers from single pollen grains of diploid (2N=2X=24) potato

Pollen grains from a diploidSolatium clone 9507-04 were used for RAPD analysis. Single pollen grains were isolated from pollen in liquid suspension, or from dry pollen spread on a glass slide, and collected in individual PCR tubes. Dry pollen isolation was found advantageous due to the convenience of handling and reduction in DNA cross-contamination. Primers UBC291 and UBC504 were selected for the RAPD analysis of both the pollen samples and the pollen donor.Solanum clone 9507-04 produced three RAPD markers UBC291-1.4, UBC291-0.8 and UBC291-0.4, under the selected PCR conditions. Amplification of three additional parental markers UBC504-1.17, UBC504-0.96 and UBC504-0.78 was also tested in a selected pollen sample. RAPD products were discernible from single pollen grains without requiring any DNA extraction procedures. The three UBC291 amplified RAPD markers of the parent segregated in the selected sample of 60 pollen grains. Potential applications of the RAPD analysis of single pollen grains are described.

491 An Evaluation of Dry Particulates as Pollen Diluents for Supplemental Mass Pollination

Pollination is essential in the production of many agricultural crops. Insufficient pollination can lead to reduced yield and lower harvest quality in many fruit and vegetables. Recent declines in insect pollinators and the use of cultural systems where compatible pollen is limiting have caused pollen-related production problems in many crops. Supplemental mass pollination (SMP) may be beneficial in such cases. However, the high cost of pollen may prohibit its use unless pollen is efficiently and uniformly applied. Our objective was to evaluate the feasibility of using selected dry particulate materials as pollen diluents for SMP. Viability was assessed in apple pollen mixed and held with selected powders (i.e., two formulations of Rilsan® nylon, polyester resin, diatomaceous earth, wheat flour, and CaCO3). Also, an assessment of inhibitory substances was made using in vitro germination tests with extracts obtained from liquid suspensions of the different particulates. Several powders, viz., Rilsan® nylon formulations, polyester resin, and wheat flour were identified as nontoxic to pollen held for 1 h as dry pollen: particle mixtures. Likewise, leachates from these diluents had no significant effect on pollen germination. Diatomaceous earth exhibited slight, but statistically significant, inhibitory effects on germination, while CaCO3 completely inhibited germination. The morphology and size of particulates were evaluated using scanning electron microscopy and will be discussed vis-a-vis pollen dispersion and metering requirements.

A Fourier transform infrared microspectroscopy study of sugar glasses: application to anhydrobiotic higher plant cells

Fourier transform infrared microspectroscopy (FTIR) was used to study glasses of pure carbohydrates and in the cytoplasm of desiccation tolerant plant organs. The position of the OH stretching vibration band ( νOH) shifted with temperature. Two linear regression lines were observed in νOH against temperature plots. The temperature at the point of intersection between these two lines coincided with the glass transition temperature ( T g), as determined by other methods. The temperature at the intersection point decreased with increasing water content, which further validates that, indeed, T g was observed. T g values that were determined for dry glucose, sucrose, maltose, trehalose and raffinose glasses were 27, 57, 91, 108 and 108°C, respectively. The shift of νOH with temperature, the wavenumber–temperature coefficient (WTC), was higher in sugar glasses having higher T g. This suggests that glasses are more loosely packed when they have higher T g. For Typha latifolia pollen and dried Craterostigma plantagineum leaves we obtained similar νOH vs. temperature plots as for carbohydrate glasses, indicating that a glass transition was observed. The T g in dry pollen was ca. 45°C and in dry plant leaves ca. 65°C, with WTC values comparable to those observed in the carbohydrates. The T g values in these tissues decreased with increasing water contents. Our data suggest that the carbohydrates that are present in the cytoplasm are primary factors contributing to the glassy state. We conclude that FTIR provides new insights in the structure of glasses in carbohydrates and in biological tissues.

A developmentally regulated MAP kinase activated by hydration in tobacco pollen.

A novel mitogen-activated protein (MAP) kinase signaling pathway has been identified in tobacco. This pathway is developmentally regulated during pollen maturation and is activated by hydration during pollen germination. Analysis of different stages of pollen development showed that transcriptional and translational induction of MAP kinase synthesis occurs at the mid-bicellular stage of pollen maturation. However, the MAP kinase is stored in an inactive form in the mature, dry pollen grain. Kinase activation is very rapid after hydration of the dry pollen, peaking at approximately 5 min and decreasing thereafter. Immunoprecipitation of the kinase activity by an anti-phosphotyrosine antibody is consistent with the activation of a MAP kinase. The kinetics of activation suggest that the MAP kinase plays a role in the activation of the pollen grain after hydration rather than in pollen tube growth.

Remarkable nectaries: structure, ecology, organophyletic perspectives I. Substitutive nectaries

In the present, first part of a series of studies on floral and extrafloral nectaries (N, Ns) that deserve interest from the structural, taxonomic, evolutionary and ecological points of view, the nuptial Ns found in members of five families are examined. They are considered to be substitutive, having evolved secondarily in subgroups that have lost another, non-homologous type of N common in their intrafamilial affinity, or that occur within an alliance that lacks floral Ns, but is presumably derived from an ancestry bearing a non-homologous type of N. The subtribe Genistinae (Fabaceae) is characterized by a closed filament tube and suppression of the nectariferous intrastaminal disk. In consequence, typically only pollen serves as a reward for pollinators. Chamaecytisus, Petteria, and Retama, to which Erinacea and Spartocytisus are added, are known to be exceptions. Field data, including behaviour of pollinators (mainly bumblebee queens), prove that they possess true nectar flowers. The site of nectar production was unknown. In the two cases examined, the liquid was found to flow out of two lateral external non-stomatic pore fields of the filament tube. As no glandular tissue is developed, the nectar probably represents phloem sap from leaking adjacent filament bundles. The taxa involved apparently regained nectar production in this distinctive manner in partly independent lineages. The perigynous disk of non-related Stylosanthes (Fabaceae) is obliterated owing to extreme elongation of the receptacle, which forms an empty “exposition tube”. Compensating this deficiency, apparently non-homologous nectar glands are seated at the tube's distal end in several species, accessible for short-tongued bees. Other species of the genus and species of related Arachis (with receptacular tubes up to 8 cm long) have closed filament tubes and no nectar. Complementing the author's previous results, atypical Ns occurring in the Primulaceae are described. In apetalous Glaux, single glandular trichomes scattered over the ovary produce the nectar, conforming to the tribe Lysimachieae, which displays (besides elaoiphores) only trichomatous Ns derived from hydathodes. Dionysia and Coris, on the other hand, share the mesenchymatous carpellary gland type of tribe Primuleae, a presumably more recent acquisition. Contrary to former belief, nectariferous Myrsinaceae do exist (Maesa). Further examples of trichomatous Ns, replacing the stomatal mesenchymatous Ns predominating in the Cucurbitaceae, are shown in species of Sicyos, Microsechium and Sechium (tribe Sicyeae), Echinocystis, Elateriopsis (Cyclanthereae), and six genera of the subfamily Zanonioideae. Trichomatous Ns, anatomically homologous to hydathode hairs, prove to be a constant feature of the three clades. While retaining a primitive level in the zanonioid members, Ns of the two other taxa exhibit parallel trends towards enlargement of glandular heads, concentration to dense carpets and internalization leading to euphily of the flowers. Concealment reaches its extreme in sect. Frantzia of Sechium, with nectariferous carpets enclosed inside ten chambers of the inflated torus. Although probably rooting in an ancestry bearing receptacular Ns, the Melastomataceae typically possess dry pollen flowers. However, as known from Neotropical members of five tribes, a sugary solution may be discharged through spontaneous ruptures of the filaments. Since nectarial tissue is absent, the fluid stems from the leaking filament bundle rich in phloem. This unique manner of nectar production was apparently archieved in independent, parallel progression lines, based on a common propensity. In addition to previous reports, novel cases are examined in species of Brachyotum, Tibouchina, Centronia and Miconia. Nectariferous fissures in most cases develop ventrally, loosely connected with the filament's prior curvature (geniculum) in the bud stage, but are independent and dorsal in Centronia. Nectaring of the petal tips in the flower bud of Medinilla magnifica, extranuptial in function, is unrelated to the foregoing situation. In this case, it rests on stomatal Ns with a pattern homologous to hydathodes seated on the margin of the foliage leaves. Some species of Sambucus, a genus basically devoid of nuptial Ns, have secondarily achieved this attractant in two different ways. Apart from the better known case of S. ebulus with a nectaring stigma, in S. javanica and relatives, numerous large cuplike nectariferous glands are distributed between the (dry) florets of the corymb, where they are exploited by insects. Hitherto taken for transformed flowers, the glands are evidently homologous to leaf-borne extranuptial Ns that occur in the same species and are widespread in the genus.

COMPARISON OF THE EFFECTS OF VARIOUS FINE PARTICLES ON IgE ANTIBODY PRODUCTION IN MICE INHALING JAPANESE CEDAR POLLEN ALLERGENS

Abstract The adjuvant effects of various fine particles [Kanto loam dust, fly ash, carbon black, diesel exhaust particles (DEP), and aluminum hydroxide (alum)] on immunoglobulin E (IgE) antibody production in female BDF) mice were examined. In experiment 1, animals both received 25 pg of each particle intranasally and were exposed to aerosolized Japanese cedar pollen allergens (JCPA) for 30 min/d at 1-wk intervals for the first 8 wk. This was followed by exposure for 30 min every 3 wk for the next 9 wk. As parameters of allergic rhinitis, measurements were made of JCPA-specific IgE and IgG antibody titers, the protein-adsorbing capacity of each type of particle, and nasal rubbing movements. The increases in anti-JCPA IgE and IgG antibody production in mice treated with aerosolized JCPA plus respective particles were significantly greater than that found with aerosolized JCPA alone. This was associated with no marked differences in the other allergic rhinitis parameters. In experiment 2, after the administration of particles as in experiment 1, about 160,000 grains of Japanese cedar pollen (JCP, native dry pollen) were dropped onto the tip of the nose of mice twice a week for 16 wk. Six weeks after the first immunization, the anti-JCPA IgE antibody titers of groups treated with the respective particles were greater than 1:20, whereas those of mice treated with JCP alone were 1:10. No significant differences in the anti-JCPA IgE and IgG antibody productions, nasal rubbing counts, or histopathological changes were observed after 18 wk. These results suggested the nature of the particles, their capacity to adsorb antigens, and/or their size may not be related to enhancement of IgE antibody production nor symptoms of allergic rhinitis. However, IgE antibody production seemed to occur earlier in mice treated with particles than in mice immunized with allergens alone.

COMPARISON OF THE EFFECTS OF VARIOUS FINE PARTICLES ON IgE ANTIBODY PRODUCTION IN MICE INHALING JAPANESE CEDAR POLLEN ALLERGENS

The adjuvant effects of various fine particles [Kanto loam dust, fly ash, carbon black, diesel exhaust particles (DEP), and aluminum hydroxide (alum)] on immunoglobulin E (IgE) antibody production in female BDF) mice were examined. In experiment 1, animals both received 25 pg of each particle intranasally and were exposed to aerosolized Japanese cedar pollen allergens (JCPA) for 30 min/d at 1-wk intervals for the first 8 wk. This was followed by exposure for 30 min every 3 wk for the next 9 wk. As parameters of allergic rhinitis, measurements were made of JCPA-specific IgE and IgG antibody titers, the protein-adsorbing capacity of each type of particle, and nasal rubbing movements. The increases in anti-JCPA IgE and IgG antibody production in mice treated with aerosolized JCPA plus respective particles were significantly greater than that found with aerosolized JCPA alone. This was associated with no marked differences in the other allergic rhinitis parameters. In experiment 2, after the administration of particles as in experiment 1, about 160,000 grains of Japanese cedar pollen (JCP, native dry pollen) were dropped onto the tip of the nose of mice twice a week for 16 wk. Six weeks after the first immunization, the anti-JCPA IgE antibody titers of groups treated with the respective particles were greater than 1:20, whereas those of mice treated with JCP alone were 1:10. No significant differences in the anti-JCPA IgE and IgG antibody productions, nasal rubbing counts, or histopathological changes were observed after 18 wk. These results suggested the nature of the particles, their capacity to adsorb antigens, and/or their size may not be related to enhancement of IgE antibody production nor symptoms of allergic rhinitis. However, IgE antibody production seemed to occur earlier in mice treated with particles than in mice immunized with allergens alone.