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Transport interactions between cadmium and zinc in roots of bread and durum wheat seedlings
Author(s) -
Hart Jonathan J.,
Welch Ross M.,
Norvell Wendell A.,
Kochian Leon V.
Publication year - 2002
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1034/j.1399-3054.2002.1160109.x
Subject(s) - cadmium , zinc , membrane , chemistry , winter wheat , ion transporter , crop , membrane transport , biophysics , agronomy , botany , biology , biochemistry , organic chemistry
Field studies have shown that the addition of Zn to Cd‐containing soils can help reduce accumulation of Cd in crop plants. To understand the mechanisms involved, this study used 109 Cd and 65 Zn to examine the transport interactions of Zn and Cd at the root cell plasma membrane of bread wheat ( Triticum aestivum L.) and durum wheat ( Triticum turgidum L. var. durum ). Results showed that Cd 2+ uptake was inhibited by Zn 2+ and Zn 2+ uptake was inhibited by Cd 2+ . Concentration‐dependent uptake of both Cd 2+ and Zn 2+ consisted of a combination of linear binding by cell walls and saturable, Michaelis‐Menten influx across the plasma membrane. Saturable influx data from experiments with and without 10 µm concentrations of the corresponding inhibiting ion were converted to double reciprocal plots. The results revealed a competitive interaction between Cd 2+ and Zn 2+ , confirming that Cd 2+ and Zn 2+ share a common transport system at the root cell plasma membrane in both bread and durum wheat. The study suggests that breeding or agronomic strategies that aim to decrease Cd uptake or increase Zn uptake must take into account the potential accompanying change in transport of the competing ion.