Comparative Study of the Pollen Protein Contents in Two Major Varieties of Cupressus arizonica Planted in Tehran

Abstract

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 35kDa. The confirmation of these aspects would facilitate the preparation of an effective extract, improving the diagnosis of the allergy to the Cupressus arizonica pollen.