Alleviation of Cu and Pb rhizotoxicities in cowpea (Vigna unguiculata) as related to ion activities at the root plasma membrane surface

Kopittke, Peter M., Kinraide, Thomas B., Wang, Peng, Blamey, F. Pax C., Reichman, Suzie M. and Menzies, Neal W. (2011) Alleviation of Cu and Pb rhizotoxicities in cowpea (Vigna unguiculata) as related to ion activities at the root plasma membrane surface. Environmental Science & Technology, 45 11: 4966-4973.


Author Kopittke, Peter M.
Kinraide, Thomas B.
Wang, Peng
Blamey, F. Pax C.
Reichman, Suzie M.
Menzies, Neal W.
Title Alleviation of Cu and Pb rhizotoxicities in cowpea (Vigna unguiculata) as related to ion activities at the root plasma membrane surface
Journal name Environmental Science & Technology  (ERA 2012 Listed)    (ERA 2010 Rank A*)   Check publisher's open access policy
Publication date 2011-06-01
Sub-type Article
DOI 10.1021/es1041404
Volume number 45
Issue number 11
ISSN 0013-936X
Start page 4966
End page 4973
Total pages 8
Place of publication United States
Publisher American Chemical Society
Collection year 2012
Language eng
Formatted abstract Cations, such as Ca and Mg, are generally thought to alleviate toxicities of trace metals through site-specific competition (as incorporated in the biotic ligand model, BLM). Short-term experiments were conducted with cowpea (Vigna unguiculata L. Walp.) seedlings in simple nutrient solutions to examine the alleviation of Cu and Pb toxicities by Al, Ca, H, Mg, and Na. For Cu, the cations depolarized the plasma membrane (PM) and reduced the negativity of ?0o (electrical potential at the outer surface of the PM) and thereby decreased {Cu2+}0o (activity of Cu2+ at the outer surface of the PM). For Pb, root elongation was generally better correlated to the activity of Pb2+ in the bulk solution than to {Pb2+}0o. However, we propose that the addition of cations resulted in a decrease in {Pb2+} 0o but a simultaneous increase in the rate of Pb uptake (due to an increase in the negativity of Em,surf, the difference in potential between the inner and outer surfaces of the PM) thus offsetting the decrease in {Pb2+}0o. In addition, Ca was found to alleviate Pb toxicity through a specific effect. Although our data do not preclude site-specific competition (as incorporated in the BLM), we suggest that electrostatic effects have an important role
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article
Collections: Official 2012 Collection
School of Agriculture and Food Sciences
 
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Created: Thu, 22 Sep 2011, 12:46:44 EST by Peng Wang on behalf of School of Agriculture and Food Sciences