Autotrophe Gewebekulturen von Ruta graveolens und deren ¹⁴CO₂-Markierungsprodukte

Summary

It is possible to obtain autotrophic callus cultures by inhibiting cell respiration. During a first passage of four weeks the cultures synthesized chlorophyll on an agar-medium with a minimum of organic substances such as sugar, amino acids and vitamins. In the second passage these cultures were kept on the same medium but were aerated with a mixture of 99% N₂ and 1% CO₂. In the third and last passage the medium contained only mineral substances and the same mixture of N₂ and CO₂ was used for aeration. This pure mineral medium was supplemented with the Hoagland's solution.

These autotrophic callus cultures were grown for about two years under these conditions and showed a growth quotient of ten.

Three different groups of tissues were taken for the ¹⁴CO₂-fixation. The first group was grown for four weeks on a heterotrophic medium and aerated with O₂. This is the socalled respirating group. The second and third group were both aerated with the mixture of N₂/CO₂ but they were grown on different mediums. One of these groups was grown on a heterotrophic medium for four weeks: these are heterotrophic photosynthesizing tissues. The third group was grown on a pure mineral medium, and these are the autotrophic photosynthesizing callus tissues.

Respirating tissues are different from photosynthesizing cultures in respect to the quantity of light-induced CO₂-fixation.

The thin-layer chromatograms reveal the difference between heterotrophic and autotrophic tissues. In the light dependent ¹⁴CO₂-incorporation the difference is in the amounts of the labelled amino acids glycine and serine. In the dark dependent incorporation the difference is found in the amount of the labelled amino acid aspartic acid. The more autotrophic these tissues are, the higher the level of the CO₂-fixation in these amino acids is.