sulfur globule oxidation is strictly dependent on the dissimilatory sulfite reductase (DSR). The DSR system is dispensable in environments with sufficiently high sulfide concentrations
dissimilatory sulfite reductase mutants incapable of complete substrate oxidation oxidize sulfide and thiosulfate about twice as fast as the wild type, while having only slightly lower growth rates (70-80% of wild type)
enzyme downregulation causes severe adaptive reactions of primary and secondary metabolism. Seedlings with 14% transcript levels compared with the wild type are early seedling lethal, while seedlings having 44% transcript levels are viable but strongly retarded in growth. Enzyme downregulation result in a higher sensitivity toward cadmium (2.6fold)