Gene for the production of cellulose discovered
An international team of researchers including Heidelberg scientists has discovered a gene that plays a key role in the production of cellulose. The results, which they present in the January 30, 1998 issue of Science, also open up new possibilities for the manufacture of bioengineered materials. The scientists carried out their investigations on the plant Arabidopsis, the thale cress. They used a mutation of the plant, which is popular for molecular biology experiments, in which the cellulose production is disrupted: the Root Swelling Mutant 1, or RSW 1 for short, variety is characterized by a typical formation of blisters on the root.
This detour enabled us to find out the sequence of the gene for cellulose synthase, reports Professor Werner Herth from the cell theory department at Heidelberg University. The decisive factor in cellulose production is the so-called synthase, an enzyme complex. Presumed candidates for cellulose synthase are the so-called rosettes in the plasma membrane of the plant cell, explains Herth. In freeze fracture under the electron microscope, these rosettes look like small flowers with six petals. Each of the six subunits forms a synthase complex. The rosettes are very sensitive to external influences.
In the mutated plant RSW 1, not only is cellulose production disturbed, the rosettes on the plasma membrane are also missing, as Herth was able to show. The research team succeeded in sequencing and cloning the mutated gene. In the end, it was even possible to compensate for the disrupted cellulose production of the mutated plant by reintroducing the gene. The scientists now want to precisely adjust the length of the sugar chains in plant cellulose and thereby develop renewable materials that could serve as supporting fibers in composites.
