Movement of mitochondria in a pollen tube of tobacco
This movie shows the movement of mitochondria in a in vitro cultured pollen tube of tobacco, Nicotiana tabacum. The mitochondria are stained with DIOC6, a fluorescing compound which is taken up by organelles with a membrane potential (more data in: http://www.probes.com). The key function of mitochondria is energy production through oxidative phosphorylation and the oxidation of lipids. In some cell types mitochondria play a role in the production of urea, the synthesis of steroid and iron-containing compounds, as well as the maintenance of the intracellular Ca2+ homeostasis.
Pollen tubes have the remarkable property that they often have a strong cytoplasmic streaming and that they only grows at the cell tip by means of excretion of vesicles. The impression of cytoplasmic streaming arises from the numerous single organelles, i.e. mitochondria, that migrate with a more or less similar velocity and direction. This movement is generated by the interaction of myosin molecules with actin filaments in presence of a chemical source of energy. Pollen tubes fulfill an important function in the biology of higher plants because they mediate the transport of the sperm cells to the egg cell so that fertilization can occur. It is a remarkable situation in which sperm cells are hosted within another cell, the pollen tube. Type the word pollen in the free search option of the image/film gallery for more images and information.
Imaging/Web text: Department of General Instrumentation (KUN) (E.S. Pierson, B. van der Linden)
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