Functional characterization of a potassium transporter gene NrHAK1 in Nicotiana rustica.
- Author:
Zhao-kui GUO
1
;
Qian YANG
;
Xiu-qing WAN
;
Pei-qiang YAN
Author Information
- Publication Type:Journal Article
- MeSH: Cation Transport Proteins; chemistry; genetics; physiology; Plant Proteins; chemistry; genetics; physiology; Potassium; metabolism; Quaternary Ammonium Compounds; pharmacology; Sodium; pharmacology; Tobacco; genetics; metabolism
- From:Journal of Zhejiang University. Science. B 2008;9(12):944-952
- CountryChina
- Language:English
- Abstract: The purpose of this study is to investigate the function of a novel potassium transporter gene (NrHAK1) isolated from Nicotiana rustica roots using yeast complement and real-time PCR technique. The complementary DNA (cDNA) of NrHAK1, 2 488 bp long, contains an open reading frame (ORF) of 2 334 bp encoding a protein of 777 amino acids (87.6 kDa) with 12 predicted transmembrane domains. The NrHAK1 protein shows a high sequence similarity to those of high-affinity potassium transporters in Mesembryanthemum, Phytolacca acinosa, Arabidopsis thaliana, and so on. We found that the NrHAK1 gene could complement the yeast-mutant defect in K+ uptake. Among several tissues surveyed, the expression level of NrHAK1 was most abundant in the root tip and was up-regulated when exposed to potassium starvation. Moreover, the transcript accumulation was significantly reduced by adding 5 mmol/L NH4+ to the solution. These results suggest that NrHAK1 plays an important role in potassium absorption in N. rustica.
