title: On the competitive uptake and transport of ions through differentiated root tissues.
abstract: We simulate the competitive uptake and transport of a mixed salt system in the differentiated tissues of plant roots. The results are based on a physical model that includes both forced diffusion and convection by the transpiration stream. The influence of the Casparian strip on regulating apoplastic flow, the focus of the paper, is modelled by varying ion diffusive permeabilities, hydraulic reflection coefficients and water permeability for transport across the endodermis-pericycle interface. We find that reducing diffusive permeabilities leads to significantly altered ion concentration profiles in the pericycle and vascular cylinder regions, while increased convective reflectivities affect predominantly ion concentrations in the cortex and endodermis tissues. The self-consistent electric field arising from ion separation is a major influence on predicted ion fluxes and accumulation rates.
authors.affiliation: Phenomics and Bioinformatics Research Centre, School of Information Technology and Mathematical Sciences, University of South Australia, Mawson Lakes, SA 5095, Australia; Australian Centre for Plant Functional Genomics, Hartley Grove, Urrbrae, SA 5064, Australia.
authors.forename: Kylie J
authors.initials: KJ
authors.lastname: Foster
authors.forename: Stanley J
authors.initials: SJ
authors.lastname: Miklavcic
mesh_terms: D001692:Biological Transport; D055592:Biophysical Phenomena; D002412:Cations; D003198:Computer Simulation; D004058:Diffusion; D001467:Hordeum / Q000502:physiology; D007477:Ions; D008954:Models, Biological; D012275:Oryza / Q000502:physiology; D010539:Permeability; D018521:Plant Physiological Phenomena; D018517:Plant Roots / Q000378:metabolism*; D054712:Salinity; D012965:Sodium Chloride; D013997:Time Factors; D014908:Triticum / Q000502:physiology; D014867:Water / Q000737:chemistry; D052584:Xylem / Q000378:metabolism
chemical_list: D002412:Cations; D007477:Ions; D014867:Water; D012965:Sodium Chloride
keywords: Casparian strip; Ion permeability; Reflection coefficient; Salinity tolerance; Salt stress