HKT transporter-mediated salinity resistance mechanisms in Arabidopsis and monocot crop plants.
The salinization of irrigated lands is increasingly detrimental to plant biomass production and agricultural productivity, as most plant species are sensitive to high concentrations of sodium (Na(+)), which causes combined Na(+) toxicity and osmotic stress. Plants have multiple Na(+)-transport systems to circumvent Na(+) toxicity. Essential physiological functions of major Na(+) transporters and their mechanisms mediating salinity resistance have been identified in Arabidopsis , including the AtSOS1, AtNHX and AtHKT1;1 transporters. As we discuss here, recent studies have demonstrated that a class of xylem-parenchyma-expressed Na(+)-permeable plant HKT transporters represent a primary mechanism mediating salt tolerance and Na(+) exclusion from leaves in Arabidopsis, and that major salt-tolerance quantitative trait loci in monocot crop plants are also based on this HKT-mediated mechanism.
Group of Molecular and Functional Plant Biology, Research Institute for Bioresources, Okayama University, Kurashiki, Okayama 710-0046, Japan. horie@rib.okayama-u.ac.jp
Tomoaki
T
Horie
Felix
F
Hauser
Julian I
JI
Schroeder
D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology; D027682:Cation Transport Proteins / Q000145:classification / Q000235:genetics / Q000502:physiology*; D018556:Crops, Agricultural / Q000235:genetics / Q000502:physiology*; D008954:Models, Biological; D009154:Mutation; D010802:Phylogeny; D010940:Plant Proteins / Q000145:classification / Q000235:genetics / Q000502:physiology*; D054712:Salinity; D055049:Salt Tolerance / Q000235:genetics / Q000502:physiology*; D012964:Sodium / Q000378:metabolism; D027981:Symporters / Q000145:classification / Q000235:genetics / Q000502:physiology*
D029681:Arabidopsis Proteins; D027682:Cation Transport Proteins; C490286:HKT1 protein, Arabidopsis; C088864:HKT1 protein, plant; D010940:Plant Proteins; D027981:Symporters; D012964:Sodium