Effects of air pollution on cup a 3 allergen in Cupressus arizonica pollen grains.

BACKGROUND: Cupressaceae is a family of plants resistant to airborne contamination, and its pollen is the main cause of winter allergic respiratory diseases, especially in North America, Japan, and Mediterranean countries. Recently, a major allergen from Cupressus arizonica pollen grains, Cup a 3, was cloned and expressed. OBJECTIVE: To study the effects of air pollution on the expression of Cup a 3, a thaumatinlike protein, in C. arizonica pollen grains using a combination of transmission electron microscopy and immunocytochemical techniques. METHODS: Observations were made in mature and hydrated C. arizonica pollen grains from various regions in Spain with different degrees of air pollution. Specimens were fixed using freezing protocols, and ultrathin sections were incubated with anti-rCup a 3 rabbit polyclonal antibodies. RESULTS: Labeling of Cup a 3 was detected in mature and hydrated C. arizonica pollen grains. It was more intense in pollen from polluted air regions, and abundant gold particles were observed as they were released through the pollen grain walls. Furthermore, gold particles remained abundant in the pollen cytoplasm. The labeling was noticeably lower in pollen grains from unpolluted air regions. CONCLUSIONS: Cup a 3 is present in the cytoplasm and walls of cypress pollen grains during the air dispersion and hydration stages. The abundance of Cup a 3 in pollen grains under polluted air conditions indicates that these cypresses intensify their activity as a defense from environmental pollution, thus strengthening their allergenicity.

Microspore development of three coniferous species: affinity of nuclei for flavonoids.

The nuclear localization of blue-staining flavanols was investigated histochemically throughout microsporogenesis in yellow cypress (Callitropsis nootkatensis (D. Don) Oerst., formerly Cupressus nootkatensis), juniper (Juniperus communis L.) and yew (Taxus baccata L.). During meiotic development, both the cytoplasm and nuclei of microspores of all species contained varying amounts of flavanols; however, the flavanols were largely confined to the nuclei in microspores just released from tetrads. Quantification by HPLC analysis indicated that, in all species, catechin and epicatechin were the dominant nuclear flavanols. At the early free microspore stage, the nuclear flavanols were barely detectable in all species, but they increased fivefold on incubation in the presence of 0.1 mM benzylaminopurine (BA) or zeatin. Histochemical studies revealed that, in addition to non-fluorescing flavanols, microspores contained yellow-fluorescing flavonoids, which yielded a distinct HPLC flavonoid profile for each species. In yellow cypress, the hydrolyzed flavonoids were identified as quercetin, apigenin, kaempferol and luteolin, whereas only quercetin and myricetin were found in microspores of juniper and in anthers of yew. Application of a UV-VIS titration technique revealed that the aglycone quercetin seems to interact more strongly with histone H3 than either glycoside rutin or kaempferol.

Comparative study of the pollen protein contents in two major varieties of Cupressus arizonica planted in Tehran.

During past few years, the Cupressus arizonica has been abundantly planted in Tehran, causing a significant increase of allergic diseases from the middle of winter to the beginning of spring. The aim of this study was the comparison of pollen protein content in two major varieties of C. arizonica planted in Tehran, including C. arizonica var. arizonica and C. arizonica var. glabra, in order to determine pollen's specificity of each variety and also to find out whether environmental conditions can influence pollen protein contents and its allergenic components. Pollen grains were directly collected from mature male cones of trees planted in different areas of the city. Pollen's proteins were extracted, and were analyzed by SDS PAGE. Total protein content of pollen extracts was measured by Bradford assay. Our investigations revealed noticeable differences in protein content of each variety. Bradford protein assay showed a higher total protein content in C. arizonica var. arizonica pollen extracts. A new major protein, with an approximate molecular weight of about 35 kDa was detected in both varieties. Immunoblotting using the serum of a cypress allergic subject showed that the protein with 35 kDa was also the major allergen of both varieties in pollen extracts. These results showed that there are some intraspecie specificities in Arizona cypress pollens. The major allergen of Cupresuss arizonica pollen, Cup a 1 (45 kDa), has been reported as the most representative protein in pollen extracts of Mediterranean countries, but in our autochthon extracts of both varieties, a protein band at 35 kDa was more representative. These observations seem to indicate that C. arizonica pollen protein content may be influenced by environmental conditions. Moreover, Immunoblot results provided a reliable indication on the allergenic activity of this new major protein band at 35 kDa. The confirmation of these aspects would facilitate the preparation of an effective extract, improving the diagnosis of the allergy to the Cupressus arizonica pollen.

Cellular fine structures and histochemical reactions in the tissue of a cypress twig preserved in Baltic amber.

A twig of a cypress plant preserved for ca. 45 Myr in Baltic amber was analysed by light and electron microscopy. Cross-sections of the whole plant showed an almost intact tissue of the entire stem and leaves, revealing, to our knowledge, the oldest and most highly preserved tissue from an amber inclusion reported so far. The preparations are based on a new technique of internal imbedding, whereby the hollow spaces within the inclusion are filled with synthetic resin which stabilizes the cellular structures during the sectioning procedure. Cytological stains applied to the sections reacted with cell walls and nuclei. A strong green auto-fluorescence of the cuticle and the resin canals in the leaves was observed. Transmission electron micrographs revealed highly preserved fine structures of cell walls, membranes and organelles. The results were compared with taxonomically related recent Glyptostrobus and Juniperus plants.