Sulfate assimilation enables the synthesis of sulfur containing compounds

Sulfate assimilation enables the synthesis of sulfur containing compounds

Sulfate is an essential constituent of living matter. In the oxidation state -II, it is present in the two amino acids cysteine and methionine, in the detoxify-ing agent glutathione, in various iron sulfur redox clusters, in peroxiredox-ins, and in thioredoxins. Plants, bacteria, and fungi are able to synthesize these compounds by assimilating sulfate taken up from the environment. The animal metabolism is dependent on sulfur containing nutrients such as methionine and cysteine. Therefore sulfate assimilation of plants is a pre-requisite for animal life, just like the carbon and nitrate assimilation dis-cussed previously.

Whereas the plant uses nitrate only in its reduced form for syntheses, sulfur, also in the form of sulfate, is an essential plant constituent. Sulfate is present in sulfolipids, which comprise about 5% of the lipids of the thy-lakoid membrane . In sulfolipids sulfur is attached as sulfonic acid via a C-S bond to a carbohydrate residue of the lipid.