Case StudyAll the information gathered during a four year project regarding the cytochemistry and cell physiology of anther and pollen development in Tradescantia bracteata L. was incorporated into a prototype of Fireflower, and now forms the basis of an on-going, ever expanding, data resource over many disparate but related projects. Botanical Research ProjectThe timing and initiation of flower development, was recorded and photographed. Environmental influences such as temperature variation, light intensity, light quality, light and dark periods, were investigated and information recorded, together with information on all the equipment used. Anatomical changes related to the differentiation of different tissues and organs were recorded and photographed chronologically, and related to changes in cytochemistry and cell physiology. These latter were related to visible changes in sub-cellular fine structure, using different types of electron microscopy, micro-spectrophotometry, and ultra-violet fluorescence photometry.
The development of anatomical structures and their chemistry which are related to the hydration of the anther and its subsequent desiccation prior to anthesis were recorded and photographed. The successive secretion and deliquescence of a series of new walls in the tapetal and sporogenous tissues leading to the isolation of the meiotic pollen mother cells from each other was filmed. The subsequent connection of the microspores to a viable, active, all encompassing periplasmodial tapetum was established. The development and chemistry of a complex cuticle on the anther was followed in time. The development of acicular crystals (raphides) was seen to occur and to be restricted to the periplasmodium and the distal ends of the anther filaments. The sudden shriveling of a ring of tissue at the ends of the anther filaments, which instigated the drying and opening of the anther, and the deterioration of the periplasmodial tapetum quickly followed the appearance of raphides. The development of crystalline moieties in specific plant tissues relating to cell death and 'necessary' anatomical differentiation was subsequently investigated in other species of plants which survive in waterlogged situations. Successive waves of cytochemical and cell-physiological activity in the pollen mother cells (sporophyte, meiotic), pollen grains (microspores, gametophyte) and the tapetal periplasmodium (sporophyte) were documented and related to specific genetic activity in their own nuclei, leading to further research projects. |
