Effects of Arsenic Species and Concentrations on Arsenic Accumulation by Different Fern Species in a Hydroponic System

• Published in: International journal of phytoremediation Vol. 7; no. 3; pp. 231 - 240
• Main Authors: Fayiga, A. O., Ma, L. Q., Santos, Jorge, Rathinasabapathi, B., Stamps, B., Littell, R. C.
• Format: Journal Article
• Language: English
• Published: United States Taylor & Francis Group 01-01-2005; Taylor & Francis Ltd
• Subjects: Arsenates - pharmacokinetics; Arsenic; Arsenic - pharmacokinetics; Biodegradation, Environmental; Bioremediation; Evolutionary biology; Ferns - classification; Ferns - metabolism; Flowers & plants; Humans; Hydroponics; hyperaccumulator; Nephrolepis exaltata; P. cretica; phytoremediation; Plant Structures; Pteris cretica; Pteris vittata; speciation; translocation; Water Pollutants - pharmacokinetics
• ISSN: 1522-6514; 1549-7879
• DOI: 10.1080/16226510500215720

Two hydroponic experiments were conducted to evaluate factors affecting plant arsenic (As) hyperaccumulation. In the first experiment, two As hyperaccumulators (Pteris vittata and P. cretica mayii) were exposed to 1 and 10 mg L
−1
arsenite (AsIII) and monomethyl arsenic acid (MMA) for 4 wk. Total As concentrations in plants (fronds and roots) and solution were determined. In the second experiment, P. vittata and Nephrolepis exaltata (a non-As hyperaccumulator) were exposed to 5 mg L
−1
arsenate (AsV) and 20 mg L
−1
AsIII for 1 and 15 d. Total As and AsIII concentrations in plants were determined. Compared to P. cretica mayii, P. vittata was more efficient in arsenic accumulation (1075-1666 vs. 249-627 mg kg
−1
As in the fronds) partially because it is more efficient in As translocation. As translocation factor (As concentration ratio in fronds to roots) was 3.0-5.6 for P. vittata compared to 0.1 to 4.8 for P. cretica. Compared to N. exaltata, P. vittata was significantly more efficient in arsenic accumulation (38-542 vs. 4.8-71 mg kg
−1
As in the fronds) as well as As translocation (1.3-5.6 vs. 0.2-0.5). In addition, P. vittata was much more efficient in As reduction from AsV to AsIII (83-84 vs. 13-24% AsIII in the fronds). Little As reduction occurred after 1-d exposure to AsV in both species indicates that As reduction was not instantaneous even in an As hyperaccumulator. Our data were consistent with the hypothesis that both As translocation and As reduction are important for plant As hyperaccumulation.