Development of the Practical Method for Ion Influx, Efflux, and Net Flux Measurement in Plant Roots

Abstract

Tracer experiments using radioisotope are powerful for the analysis of mineral uptake mechanisms in plant roots. In this study, we aimed to establish a quantitative method for measuring ion fluxes, i.e. net flux, influx, and efflux, which can be used to phenotyping of the mutants and natural variations. Consistency of obtained flux values for Mg²⁺ and Na⁺ was examined, and it was found that radioisotope absorption time of 20 s gave influx rate and an absorption time of more than 15 min gave net flux rate in rice roots. Furthermore, it was suggested that the longest possible radioisotope labeling time is necessary to increase the accuracy of the calculated efflux rate.