A web-accessible computer program for calculating electrical potentials and ion activities at cell-membrane surfaces

作者：Kopittke Peter M^*; Wang Peng; Menzies Neal W; Naidu Ravi; Kinraide Thomas B

来源：Plant and Soil, 2014, 375(1-2): 35-46.

DOI：10.1007/s11104-013-1948-x

• Electrical potential
• Mineral nutrition
• Plant growth
• Plant-ion interactions
• Plasma membrane
• Toxicity

Increasing evidence indicates that plant responses to ions (uptake/transport, inhibition, and alleviation of inhibition) are dependent upon ion activities at the outer surface of root-cell plasma membranes (PMs) rather than activities in the bulk-phase rooting medium. %26lt;br%26gt;A web-accessible computer program was written to calculate the electrical potential (psi) at the outer surface of root-cell PMs (psi (PM)). From these values of psi (PM), activities of ion I with charge Z ({I (Z)}) can be calculated for the outer surface of the PM ({I (Z)}(PM)). In addition, psi and {I (Z)} in the Donnan phase of the cell walls (psi (CW) and {I (Z)}(CW)) can be calculated. %26lt;br%26gt;By reanalysing published data, we illustrate how this computer program can assist in the investigation of plant-ion interactions. For example, we demonstrate that in saline solutions, both Ca deficiency and Na uptake are more closely related to {Ca2+}(PM) and {Na+}(PM) than to {Ca2+}(b) and {Na+}(b) (activities in the bulk-phase media). Additional examples are given for Zn and P nutrition, Ni toxicity, and arsenate uptake. %26lt;br%26gt;The computer program presented here should assist others to develop an electrostatic view of plant-ion interactions and to re-evaluate some commonly-held views regarding mechanisms of ion transport, toxicity, competition among ions, and other phenomena.

• 出版日期2014-2