Transport and metabolism of arsenicals in arsenic hyperaccumulating ferns (Pteris vittata)

This thesis work provides mechanistic insight into the transport arsenicals by arsenic hyperaccumulating ferns. Aquaporin inhibition using silver significantly decreased arsenite accumulation in the plants indicating arsenite movement into the roots of these ferns is likely mediated by major intrinsic proteins. Kinetics study of organoarsenical revealed that the nature of uptake in arsenic hyperaccumulating fern, P. vittata is passive but results are inconclusive. Another critical part of this research was to investigate enzymatic arsenate reduction contributing to the metabolism of arsenic by P. vittata. Results support the existence of a root localized putative arsenate reductase-like enzyme dependent on glutathione as an electron donor. Arsenate reductases have been reported to exist in bacteria, yeast and mammalian systems but not in plant systems. A complete understanding of the biochemistry and physiology of arsenic transport and metabolism in these plants provide significant development in the offing towards arsenic phytoremediation using arsenic hyperaccumulators.