Growing and experimenting with plants in space is relatively new. It began as far as the year 1960, but sophisticated experiments started on the board the International Space Station (ISS). Their aim is to support basic understanding of plant growth and development processes under normal conditions on Earth and under space conditions (e.g. at reduced or no gravity). In addition, they aim to optimize plant growing in space which could support nutrition of astronauts on longer man-crewed missions and at research bases on Moon and Mars. Key differences between plant cultivation on Earth compered to space are reduced gravity, space radiation and weaker magnetic field. In this thesis I will focus on reduced gravity. Its most prominent effect is on the exchange of gases, which results from the lack of convection and form high diffusive resistance. As a consequence, processes such as transpiration and uptake of oxygen to roots are severely hindered. Changed gravity influences growth responses such as gravitropism and phototropism, cell structure, divisions and signaling. Normal plant growth and development can be assured by using special growth chamber with controlled atmosphere (which includes removal of ethylene), nutrient and water supply (special substrates) and illumination. Although many obstacles of growing plants in space have been solved, growth chambers are still limited by their size. Currently there is only one grow chamber available on the ISS from which the crew could get some food for consumption. Still a lot of progress can be expected in this field in the future.
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