Arsenic chemistry in the rhizosphere of Pteris vittata L. and Nephrolepis exaltata L.
This greenhouse experiment evaluated the influence of arsenic uptake by arsenic hyperaccumulator Pteris vittata L. and non-arsenic hyperaccumulator Nephrolepis exaltata L. on arsenic chemistry in bulk and rhizosphere soil. The plants were grown for 8 weeks in a rhizopot with a soil containing 105 mg kg(-1) arsenic. The soil arsenic was fractionated into five fractions with decreasing availability: non-specifically bound (N), specifically bound (S), amorphous hydrous-oxide bound (A), crystalline hydrous-oxide bound (C), and residual (R). P. vittata produced larger plant biomass (7.38 vs. 2.32 mg plant(-1)) and removed more arsenic (2.61 vs. 0.09 mg pot(-1) arsenic) than N. exaltata. Plant growth reduced water-soluble arsenic, and increased soil pH (P. vittata only) in the rhizosphere soil. P. vittata was more efficient than N. exaltata to access arsenic from all fractions (39-64% vs. 5-39% reduction). However, most of the arsenic taken up by both plants was from the A fraction (67-77%) in the rhizosphere soil, the most abundant (61.5%) instead of the most available (N fraction).
Silva Gonzaga
Maria I
MI
Soil and Water Science Department, University of Florida, Gainesville, FL 32611-0290, USA.
Santos
Jorge A G
JA
Ma
Lena Q
LQ
D001151:Arsenic / Q000032:analysis*; D001673:Biodegradation, Environmental; D018533:Biomass; D001711:Biotransformation; D002244:Carbon / Q000032:analysis; D029624:Ferns / Q000378:metabolism*; D006812:Humic Substances; D006863:Hydrogen-Ion Concentration; D018515:Plant Leaves / Q000737:chemistry; D032495:Pteris / Q000378:metabolism; D027343:Rhizome / Q000378:metabolism*; D012987:Soil / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*; D012995:Solubility
D006812:Humic Substances; D012987:Soil; D012989:Soil Pollutants; D002244:Carbon; D001151:Arsenic