Measurement of trace metal influx in plants: a case study with Co

The analysis of transport systems involved in the uptake of trace metals in plants is complicated by technical difficulties associated with measurement of uptake and by the likely presence of multiple transporters with broad specificity. In this study, influx of Co was used to illustrate the problems involved and potential solutions. Issues surrounding kinetic descriptions of transport, multiple uptake systems, specificity of transporters, pH effects and the role of membrane surface charge in determining fluxes are addressed. A list of criteria for validation of flux measurements is provided.