Pollenkitt development and composition in Tilia platyphyllos (Tiliaceae) analysed by conventional and energy filtering TEM

The loculus content and tapetum during pollen development in Lilium

“…The loculus can be a storage site for developing microspores. The use of locular substances by pollen grains changes during ontogenesis: polysaccharides, pectins and proteins might be incorporated into the microspore cytoplasm for metabolism and vacuolation (Keijzer and Cresti 1987), whereas the pollenkitt probably does not penetrate the pollen grain but remains on the wall surface and acts as a sticky attractor for pollinators (Hesse 1993), or it may be involved in compatibility (Ruiter et al 1997).…”

“…During late microspore development or pollen mitosis, the pollenkitt (Parkinson and Pacini 1995) invades the loculus and settles on the surface of the pollen wall (Fitzgerald et al 1994). It consists mainly of protein and lipid droplets (Weber 1992;Hesse 1993;Weber 1996;Ruiter et al 1997).…”

Pollenkitt – its composition, forms and functions

“…with entomophilous and related pollination syndromes, but not in gymnosperms (for details and reviews see Hesse 1978aHesse -d, 1979aHesse -e, 1980aHesse -c, 1981aHesse , b, 1984. Pollenkitt as pollen binding agent is typical of almost all entomophilous plants with monads and tetrads (Hesse, 1993); however, the distribution of pollenkitt on pollen surfaces is highly variable. The characters of the so-called Pollenverkittung (for this perfectly apt German word, a rough translation is ''the variable degree of pollen stickiness''), namely amount, consistency and distribution of pollenkitt in relation to exine ultrastructure has been investigated in closely related genera with anemo-and entomophilous species, for example, Plantago, Fraxinus, Acer, Carex, Sanguisorba, and Artemisia (Hesse, 1979c).…”

“…Pollenkitt is a hydrophobic mixture of materials, composed mainly of saturated and unsaturated lipids (Dobson, 1988), carotenoids (Hesse, 1993;Lunau, 1995), flavonoids (Wiermann and Gubatz, 1992), proteins and carbohydrates (Parkinson and Pacini, 1995;Santos et al, 2003;Weber, 1996, also for review). Differences in pollenkitt composition have been reported in the heterantherous species Lagerstroemia indica which has two pollen forms produced by pollinating and feeding anthers (Nepi et al, 2003).…”

An approach to the knowledge of pollen and allergen diversity through lipid transfer protein localisation in taxonomically distant pollen grains

“…The presence of nsLTPs in the A. latifolia pollenkitt indicates that nsLTPs form part of the chemical composition of the pollenkitt or they are involved in the traffic of defence proteins. The pollenkitt is a hydrophobic mixture of materials, composed primarily of saturated and unsaturated lipids, carotenoids (Dobson, 1988;Hesse, 1993) and proteins and carbohydrates (Piffanelli & Murphy, 1998;Santos et al, 2003). The oleo-pollenin is considered the major protein component of the pollenkitt (Murphy & Ross, 1998;Murhpy, 2001).…”