Pteris vittata - Revisited: Uptake of As and its speciation, impact of P, role of phytochelatins and S

Vetterlein, Doris; Wesenberg, Dirk; Nathan, Petra; Bräutigam, Anja; Schierhorn, Angelika; Mattusch, Jürgen; Jahn, Reinhold

Pteris vittata - Revisited: Uptake of As and its speciation, impact of P, role of phytochelatins and S

2009

Pteris vittata is known to hyperaccumulate As but the mechanism is poorly understood. We found an increase of As concentration with increasing soil solution As concentrations, but P application had no impact, although plant P concentrations responded to different rates of P supply. As in fronds was dominantly (82-89%) present in the form of AsIII. In roots we detected 45% as AsIII which is higher than reported in previous studies and supports substantial As-reduction to take place in roots. We detected PC2/3GS-AsIII, PC2-GS-AsIII and (PC2)2-AsIII in increasing amounts with application of As. The total amount of PC was in the range reported previously and far too small to assign a significant role in As detoxification to PCs. The close correlation between S and As in fronds and the lack of data on sulphur uptake and metabolism indicates the need for a detailed investigation on sulphur nutritional status and As metabolism in P. vittata. As-PC complexes were detected in increasing amounts with increasing As availability, but total amounts were small and do not explain the close correlation between S and As in fronds.

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