Roles of organic acids and nitrate in the long-distance transport of cobalt (Co) in xylem saps of hyperaccumulator Alyssum murale and non-hyperaccumulator Trifolium subterraneum were studied under hydroponic conditions. Organic acids (oxalic, malic, malonic, citric, and fumaric) and nitrate in xylem sap samples were separated and determined simultaneously by reversed-phase high performance liquid chromatography after solid-phase extraction with nanosized hydroxyapatite. Results indicated that Co treatment significantly increased the concentrations of xylem oxalic and malic acids for the hyperaccumulator A. murale compared to the control but significantly decreased the concentrations of xylem nitrate and malonic acid; concentrations of citric acid in xylem sap samples did not show significant difference between the control and Co treatments. By analyzing the relationship between the concentrations of organic acids, nitrate, and concentrations of Co in xylem saps, it could be concluded that oxalic and malic acids in xylem saps seemed to participate in the long-distance Co translocation process, and citric acid did not relate to the xylem Co transport of A. murale and T. subterraneum. Our work might be very useful for understanding the mechanism of long-distance transport of heavy metals in hyperaccumulator.

Item Type:	Refereed Article
Keywords:	cobalt, xylem sap, organic acids, nitrate, Alyssum murale, Trifolium subterraneum
Research Division:	Chemical Sciences
Research Group:	Analytical Chemistry
Research Field:	Separation Science
Objective Division:	Expanding Knowledge
Objective Group:	Expanding Knowledge
Objective Field:	Expanding Knowledge in the Chemical Sciences
Author:	Wei, Z (Professor Zhenggui Wei)
ID Code:	91141
Year Published:	2009
Web of Science® Times Cited:	16
Deposited By:	Austn Centre for Research in Separation Science
Deposited On:	2014-05-09
Last Modified:	2014-06-16
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