Highly efficient xylem transport of arsenite in the arsenic hyperaccumulator Pteris vittata.

The hyperaccumulator Pteris vittata translocates arsenic (As) from roots to fronds efficiently, but the form of As translocated in xylem and the main location of arsenate reduction have not been resolved. Here, P. vittata was exposed to 5 microM arsenate or arsenite for 1-24 h, with or without 100 microM phosphate. Arsenic speciation was determined in xylem sap, roots, fronds and nutrient solutions by high-performance liquid chromatography (HPLC) linked to inductively coupled plasma mass spectrometry (ICP-MS). The xylem sap As concentration was 18-73 times that in the nutrient solution. In both arsenate- and arsenite-treated plants, arsenite was the predominant species in the xylem sap, accounting for 93-98% of the total As. A portion of arsenate taken up by roots (30-40% of root As) was reduced to arsenite rapidly. The majority (c. 80%) of As in fronds was arsenite. Phosphate inhibited arsenate uptake, but not As translocation. More As was translocated to fronds in the arsenite-treated than in the arsenate-treated plants. There was little arsenite efflux from roots to the external solution. Roots are the main location of arsenate reduction in P. vittata. Arsenite is highly mobile in xylem transport, possibly because of efficient xylem loading, little complexation with thiols in roots, and little efflux to the external medium.

[1]  S. McGrath,et al.  Rapid reduction of arsenate in the medium mediated by plant roots. , 2007, The New phytologist.

[2]  Y. Qin,et al.  Uptake and accumulation of arsenic by 11 Pteris taxa from southern China. , 2007, Environmental pollution.

[3]  David E Salt,et al.  Localizing the biochemical transformations of arsenate in a hyperaccumulating fern. , 2006, Environmental science & technology.

[4]  L. Ma,et al.  Three new arsenic hyperaccumulating ferns. , 2006, The Science of the total environment.

[5]  David E Salt,et al.  A Novel Arsenate Reductase from the Arsenic Hyperaccumulating Fern Pteris vittata1 , 2006, Plant Physiology.

[6]  Om Parkash Dhankher,et al.  Hyperaccumulation of arsenic in the shoots of Arabidopsis silenced for arsenate reductase (ACR2). , 2006, Proceedings of the National Academy of Sciences of the United States of America.

[7]  J. Feldmann,et al.  Uptake, translocation and transformation of arsenate and arsenite in sunflower (Helianthus annuus): formation of arsenic-phytochelatin complexes during exposure to high arsenic concentrations. , 2005, The New phytologist.

[8]  F. Fodor,et al.  Arsenic speciation in xylem sap of cucumber (Cucumis sativus L.) , 2005, Analytical and bioanalytical chemistry.

[9]  Yong-Guan Zhu,et al.  Characterization of Arsenate Reductase in the Extract of Roots and Fronds of Chinese Brake Fern, an Arsenic Hyperaccumulator1 , 2005, Plant Physiology.

[10]  N. Caille,et al.  Comparison of root absorption, translocation and tolerance of arsenic in the hyperaccumulator Pteris vittata and the nonhyperaccumulator Pteris tremula. , 2004, The New phytologist.

[11]  R. Chenc,et al.  Arsenic speciation and transport in Pteris vittata L . and the effects on phosphorus in the xylem sap , 2005 .

[12]  L. Kochian,et al.  Mechanisms of arsenic hyperaccumulation in Pteris species: root As influx and translocation , 2004, Planta.

[13]  L. Kochian,et al.  Phytofiltration of arsenic from drinking water using arsenic-hyperaccumulating ferns. , 2004, Environmental science & technology.

[14]  A. Raab.  The nature of arsenicphytochelatin conplexes in Holcus lanatus and Pteris cretica , 2004 .

[15]  S. McGrath,et al.  The role of phytochelatins in arsenic tolerance in the hyperaccumulator Pteris vittata. , 2003, The New phytologist.

[16]  Fang-Jie Zhao,et al.  Phytoextraction of metals and metalloids from contaminated soils. , 2003, Current opinion in biotechnology.

[17]  Jean-François Gaillard,et al.  XAS speciation of arsenic in a hyper-accumulating fern. , 2003, Environmental science & technology.

[18]  A. Meharg.  Variation in arsenic accumulation - hyperaccumulation in ferns and their allies: Rapid report. , 2003, The New phytologist.

[19]  C. Tu,et al.  Arsenic speciation and distribution in an arsenic hyperaccumulating plant. , 2002, The Science of the total environment.

[20]  Enzo Lombi,et al.  Arsenic distribution and speciation in the fronds of the hyperaccumulator Pteris vittata. , 2002, The New phytologist.

[21]  Andrea Raab,et al.  Mechanisms of Arsenic Hyperaccumulation in Pteris vittata. Uptake Kinetics, Interactions with Phosphate, and Arsenic Speciation1 , 2002, Plant Physiology.

[22]  S. McGrath,et al.  Arsenic hyperaccumulation by different fern species , 2002 .

[23]  P. Visoottiviseth,et al.  The potential of Thai indigenous plant species for the phytoremediation of arsenic contaminated land. , 2002, Environmental pollution.

[24]  J. Ranville,et al.  Preserving the distribution of inorganic arsenic species in groundwater and acid mine drainage samples. , 2002, Environmental science & technology.

[25]  C. Tu,et al.  Effects of arsenic concentrations and forms on arsenic uptake by the hyperaccumulator ladder brake. , 2002, Journal of environmental quality.

[26]  Yong Cai,et al.  A fern that hyperaccumulates arsenic , 2001, Nature.

[27]  M J George,et al.  Reduction and coordination of arsenic in Indian mustard. , 2000, Plant physiology.

[28]  E. Grill,et al.  Detoxification of arsenic by phytochelatins in plants. , 2000, Plant physiology.

[29]  H. Schat,et al.  TOXICITY OF ARSENATE IN SILENE VULGARIS, ACCUMULATION AND DEGRADATION OF ARSENATE-INDUCED PHYTOCHELATINS , 1999 .