Pollenkitt formation in Ilex paraguariensis A.St.Hil. (Aquifoliaceae)

• DOI: 10.1007/s00606-002-0257-2
• Publication Date: 2003-12-11T01:54:55Z
• Authors: R. P. Santos; J. E. A. Mariath; M. Hesse
• Keywords: 0106 biological sciences; 106008 Botanik; 01 natural sciences; 106008 Botany

We investigated the cellular and organelle transformations during the formation of the pollenkitt in the secretory tapetum of Ilex paraguariensis. After the dissolution of the callose surrounding the young microspores, the elaioplasts of the tapetum produce many globules of saturated and unsaturated lipids (plastoglobules). Further on, oleosomes with unsaturated lipids, synthesized in the endoplasmic reticulum, accumulate in the tapetal cytoplasm. In contrast to other species, the plastoglobule production seems to precede the oleosome synthesis. The tapetum shows signs of cellular maturation in the late vacuolated microspore stage, when the plastoglobules and oleosomes coalesce and form the pollenkitt mass. In mature stages of the tapetum the pollenkitt is released into the loculus. Finally, it is mainly deposited on the exine, according to the entomophilous character of this species. The mode of pollenkitt formation in Ilex para guariensis and its transfer to the pollen surface is slightly dissimilar to other Angiosperms.