title: A root's ability to retain K+ correlates with salt tolerance in wheat.
abstract: Most work on wheat breeding for salt tolerance has focused mainly on excluding Na(+) from uptake and transport to the shoot. However, some recent findings have reported no apparent correlation between leaf Na(+) content and wheat salt tolerance. Thus, it appears that excluding Na(+) by itself is not always sufficient to increase plant salt tolerance and other physiological traits should also be considered. In this work, it was investigated whether a root's ability to retain K(+) may be such a trait, and whether our previous findings for barley can be extrapolated to species following a 'salt exclusion' strategy. NaCl-induced kinetics of K(+) flux from roots of two bread and two durum wheat genotypes, contrasting in their salt tolerance, were measured under laboratory conditions using non-invasive ion flux measuring (the MIFE) technique. These measurements were compared with whole-plant physiological characteristics and yield responses from plants grown under greenhouse conditions. The results show that K(+) flux from the root surface of 6-d-old wheat seedlings in response to salt treatment was highly correlated with major plant physiological characteristics and yield of greenhouse-grown plants. This emphasizes the critical role of K(+) homeostasis in plant salt tolerance and suggests that using NaCl-induced K(+) flux measurements as a physiological 'marker' for salt tolerance may benefit wheat-breeding programmes.
authors.affiliation: School of Agricultural Science, University of Tasmania, Private Bag 54, Hobart, Tasmania 7001, Australia. Tracey.Cuin@utas.edu.au
authors.forename: Tracey Ann
authors.initials: TA
authors.lastname: Cuin
authors.forename: Stewart A
authors.initials: SA
authors.lastname: Betts
authors.forename: Rémi
authors.initials: R
authors.lastname: Chalmandrier
authors.forename: Sergey
authors.initials: S
authors.lastname: Shabala
mesh_terms: D018533:Biomass; D002462:Cell Membrane / Q000502:physiology; D010641:Phenotype; D018517:Plant Roots / Q000235:genetics / Q000502:physiology*; D011188:Potassium / Q000378:metabolism*; D012965:Sodium Chloride / Q000378:metabolism*; D014908:Triticum / Q000235:genetics / Q000502:physiology*
chemical_list: D012965:Sodium Chloride; D011188:Potassium