Abstract
Almost all cell membrane surfaces (CMS) are intrinsically negatively charged. These negative charges create a surface electrical potential (φ0) which affects ion concentrations at the CMS and consequently affects the phytotoxicity of metallic cations and metalloid anions in different ways. The φ0 is also controlled by the ionic composition of the bulk-phase medium (BM). Common cations, especially H+, Ca 2+ and Mg2+, can reduce the negativity of φ0 by ionic screening and binding. Treatments that reduce the negativity of φ0 would reduce the surface activity of Cu 2+ ({Cu2+}0) and increase the surface activity of arsenate ({As(V)}0) at the CMS, and consequently alleviation of Cu2+ toxicity but aggravation As toxicity would be expected. It is the φ0, rather than site-specific competition, that plays the principal role in ionic interactions and biotic effects.
Original language | English |
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Pages (from-to) | 42-43 |
Number of pages | 2 |
Journal | Plant Signaling and Behavior |
Volume | 4 |
Issue number | 1 |
DOIs | |
State | Published - Jan 2009 |
Externally published | Yes |
Keywords
- Arsenate
- Biotic ligand model
- Cell membrane surface potential
- Copper
- Gouy-Chapman-Stern model
- Ion-plant interaction
- Phytotoxicity