Comparative study of allergenicity of mature and immature pollen grains of Achillea wilhelmsii

Pollen grains are male gametophytes of flowering plants that with self interference in fertilization have an important role in plant fertilization, increasing fertilization and improving quality of products. Pollen grains are of important allergenic plants and 80-90% of allergens have plant origin. Achillea plant has medical usage and grows in different regions of the country. This research is done in order to acquire scientific information pertaining to pollen grains allergenicity in their development stages and comparing mature and immature pollen grains allergenicity. In this experimental study Achillea plant pollen grains in different developmental stages were collected around Isfahan city and samples were studied using light and electronic microscopy (SEM). Pollen extracts were prepared by incubating pollen grains in phosphate buffered saline, PH: 7.4. The allergenicity experiment was done on male Guinea pigs (Hartley strain, 350-500g weight, 4-6 week-old, Pausteur institute of Iran) and electrophoresis of proteins was done on 12% SDS- polyacrylamide gel. Data were analyzed using one way ANOVA and Duncan test. Images of light and electronic microscopy showed pollens from ellipse-spherical type, with two colpate and echinate exine. The skin tests in Guinea pigs treated with pollen extracts indicated wheal with diameter larger than control group. In clinical tests, the numbers of eosinophils, neutrophils and IgE were increased in animals treated with pollen extract comparing control group. In SDS- PAGE protein profiles, 6 richly colored protein bands were seen in mature pollens in 14.4 to 66 KD and 5 slightly colored protein bands in immature pollens in 14.4 to 45 KD. This research shows changes of immature pollens` ellipse morphology to spherical form in mature pollens, partial increasing in accumulation and height of exine surface echins, changes in quality and quantity of immature and mature pollen grains and difference in their allergenic severity.