Int. J. Mol. Sci. 2013, 14(4), 7660-7680; doi:10.3390/ijms14047660
Review

Plant High-Affinity Potassium (HKT) Transporters Involved in Salinity Tolerance: Structural Insights to Probe Differences in Ion Selectivity

Received: 31 January 2013; in revised form: 7 March 2013 / Accepted: 28 March 2013 / Published: 9 April 2013
(This article belongs to the Special Issue Abiotic and Biotic Stress Tolerance Mechanisms in Plants)
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract: High-affinity Potassium Transporters (HKTs) belong to an important class of integral membrane proteins (IMPs) that facilitate cation transport across the plasma membranes of plant cells. Some members of the HKT protein family have been shown to be critical for salinity tolerance in commercially important crop species, particularly in grains, through exclusion of Na+ ions from sensitive shoot tissues in plants. However, given the number of different HKT proteins expressed in plants, it is likely that different members of this protein family perform in a range of functions. Plant breeders and biotechnologists have attempted to manipulate HKT gene expression through genetic engineering and more conventional plant breeding methods to improve the salinity tolerance of commercially important crop plants. Successful manipulation of a biological trait is more likely to be effective after a thorough understanding of how the trait, genes and proteins are interconnected at the whole plant level. This article examines the current structural and functional knowledge relating to plant HKTs and how their structural features may explain their transport selectivity. We also highlight specific areas where new knowledge of plant HKT transporters is needed. Our goal is to present how knowledge of the structure of HKT proteins is helpful in understanding their function and how this understanding can be an invaluable experimental tool. As such, we assert that accurate structural information of plant IMPs will greatly inform functional studies and will lead to a deeper understanding of plant nutrition, signalling and stress tolerance, all of which represent factors that can be manipulated to improve agricultural productivity.
Keywords: bacterial TrkH K+ transporter; cation exclusion; protein structure and function; selectivity filter and pore; structural analysis
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MDPI and ACS Style

Waters, S.; Gilliham, M.; Hrmova, M. Plant High-Affinity Potassium (HKT) Transporters Involved in Salinity Tolerance: Structural Insights to Probe Differences in Ion Selectivity. Int. J. Mol. Sci. 2013, 14, 7660-7680.

AMA Style

Waters S, Gilliham M, Hrmova M. Plant High-Affinity Potassium (HKT) Transporters Involved in Salinity Tolerance: Structural Insights to Probe Differences in Ion Selectivity. International Journal of Molecular Sciences. 2013; 14(4):7660-7680.

Chicago/Turabian Style

Waters, Shane; Gilliham, Matthew; Hrmova, Maria. 2013. "Plant High-Affinity Potassium (HKT) Transporters Involved in Salinity Tolerance: Structural Insights to Probe Differences in Ion Selectivity." Int. J. Mol. Sci. 14, no. 4: 7660-7680.

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