Rice potassium transporter OsHAK1 is essential for maintaining potassium‐mediated growth and functions in salt tolerance over low and high potassium concentration ranges. (16th July 2015)

• Record Type: Journal Article
• Authors: Chen, Guang; Hu, Qingdi; Luo, Le; Yang, Tianyuan; Zhang, Song; Hu, Yibing; Yu, Ling; Xu, Guohua
• Is Part Of: Plant, cell and environment. Volume 38:Number 12(2015:Dec.)
• Page Start: 2747
• Page End: 2765
• Publication Date: 2015-07-16
• Subjects: Oryza sativa -- potassium homeostasis -- potassium acquisition -- potassium transportation; Plant physiology -- Periodicals; Plant cells and tissues -- Periodicals; Plant communities -- Periodicals; 581.105
• DOI: 10.1111/pce.12585
• Languages: English
• ISSNs: 0140-7791

Abstract

Abstract: Potassium (K) absorption and translocation in plants rely upon multiple K transporters for adapting varied K supply and saline conditions. Here, we report the expression patterns and physiological roles of OsHAK1, a member belonging to the KT / KUP / HAK gene family in rice ( O ryza sativa L.). The expression of OsHAK1 is up‐regulated by K deficiency or salt stress in various tissues, particularly in the root and shoot apical meristem, the epidermises and steles of root, and vascular bundles of shoot. Both oshak1 knockout mutants in comparison to their respective Dongjin or Manan wild types showed a dramatic reduction in K concentration and stunted root and shoot growth. Knockout of OsHAK1 reduced the K absorption rate of unit root surface area by ∼50–55 and ∼30%, and total K uptake by ∼80 and ∼65% at 0.05–0.1 and 1 mm K supply level, respectively. The root net high‐affinity K uptake of oshak1 mutants was sensitive to salt stress but not to ammonium supply. Overexpression of OsHAK1 in rice increased K uptake and K/Na ratio. The positive relationship between K concentration and shoot biomass in the mutants suggests that OsHAK1 plays an essential role in K‐mediated rice growth and salt tolerance over low and high K concentration ranges. Abstract : A rice potassium transporter, OsHAK1, is up‐regulated by K deficiency or salt stress in various tissues, particularly in the root and shoot apical meristem. Knockout of OsHAK1 reduced the K absorption rate of unit root surface area by ∼50–55% and ∼30%, and total K uptake by ∼80% and ∼65% at 0.05–0.1 mM and 1 mM K supply level, respectively. The positive relationship between K concentration and shoot biomass in the mutants suggests that OsHAK1 plays an essential role in K‐mediated rice growth over low and high K concentration ranges.