ELECTRON AND X-RAY MICROSCOPIC ANALYSES OF REAGGREGATED MATERIALS OBTAINED AFTER FRACTIONATION OF DISSOLVED SPOROPOLLENIN

Exines from Typha angustifolia L. pollen were dissolved in hot 2-amino ethanol. The solubilisate was successively fractionated and reaggregat ed via a dialysis cascade with dialysis tubings of different exclusion volumina. Four fractions of reaggregated material with different mole cular mass were obtained. Fraction 1 with a molecular mass above 25,00 0 Da, fraction 2 with a molecular mass between 10,000-25,000 Da, fract ion 3 with a molecular mass between 5,000-10,000 Da, and fraction 4 of a molecular mass lower than 5,000 Da. The fractions were comparativel y analysed by scanning and transmission electron microscopy and X-ray microscopy. The material of the fractions with a molecular mass above 10,000 Da exhibit high congruence to the initial material. Analysis of the reaggregated material with the lowest molecular mass revealed spe cial distinct substructures which in form and size showed high similar ities to substructures of exines described in literature. In detail, s pherical substructures consisting of an electron-dense core surrounded by an electron-transparent corona and in addition elongated substruct ures with a distinctive surface sculpture were detected.