Search

(2000). Pollen-allergy as an ecological phenomenon: A review. Plant Biosystems - An International Journal Dealing with all Aspects of Plant Biology: Vol. 134, No. 3, pp. 341-352.

Using rapid fixation and freeze substitution method, the ultrastructure of the cytoplasm, including the membrane system, of Betula pendula pollen is well preserved. The cytoplasm of Betula pollen appears compact and organelles such as Golgi and RER are not yet demonstrating any secretory activities. The cytoplasm streaming is not established because the pollen grains are not completely hydrated and the microfilaments are still polymerized in bundless. The cytoplasm of the generative cell is well preserved including the cell wall like structure and cytoskeletal complexes present in the cell. Moreover the application of rapid freeze fixation of microspores and pollen grains of Betula showed clear details of ultrastructure of the Zwischenkorper (Z) at the aperture sites and the Z-layer (ZL) between the apertures. They are mainly composed of dense helical units that extend from the plasmalemma. Rapid freezing improves to a great extent the fixation of the delicate cell structure of the tapetum. After freeze f...

The major allergen Bet ver 1 of Betula pendula (= B. verrucosa) pollen grains has been localized by gold labelling with monoclonal antibodies. The allergen is located predominantly in the starch grains and to a slight extent in the exine and intine. The possibility that environmental factors might influence the liberation of allergenic compounds present in birch pollen grains is discussed.

The cytoskelelon during the pollen tube growth - The process of pollen tube growth is reviewed, with a particular attention to the cytoskeleton of the pollen tube. A relevant emphasis is also given to the role of motor proteins during the translocation of organelles, generative cell and vegetative nucleus.

(1993). II polline e tubetto pollinico. Giornale botanico italiano: Vol. 127, No. 5, pp. 875-889.

The cytoskeleton in the reproductive organs of Angiosperm plants. In the recent years a cytoskeletal apparatus has been discovered in the reproductive organs of Angiosperm plants. Microfilaments and microtubules are the main cytoskeletal components in both male and female apparatus. The presence of other cytoskeletal proteins has been showed in the pollen and pollen tube. It is becomming clear that the cytoskeletal apparatus plays a fundamental role in the fertilization process.

Burkard volumetric samplers were used to carry out research on airborne pollen in the Ascoli Piceno and Siena atmosphere in the period April-September 1981. Total production in the period in question was quantitatively similar, with a prevalence of non-arboreal pollen in both stations. The overall trend has shown a positive correlation between the two stations. Differences were recorded with regard to the period of pollination and the quantity of pollen produced by Quercus, Poaceae, Oleaceae, Castanea, Plantaginaceae and Compositae.

The composition of the stigmatic exudate of Citrus limon (L.) Burm. - Biochemical analyses of the stigmatic exudate of Citrus limon (L.) Burm. have revealed the presence of lipids, polysaccharides, proteins, phenols, free aminoacids and alkaloids. The role of stigma secretion is discussed in relation to pollen activation and recognition and the pollen tube growth.

A technique for observing anthers fixed and embedded for a transmission electron microscope (TEM), after resin removal, with a scanning electron microscope (SEM), is described. This technique affords two different types of images from the same pollen grain, bidimensional by TEM and tridimensional by SEM.