Cloning and expression analysis of potassium channel gene NKT3 from Nicotiana tabacum

Abstract

Potassium (K⁺) is the predominant inorganic ion of plant cells. K⁺ channels in higher plant cells play an important role in regulating the influx and efflux of K⁺ from cells, and activity of these channels might be involved in plant stress resistance. A completely new K⁺ channel gene of Nicotiana tabacum was obtained through homologous cloning strategy. The complete cDNA sequence was submitted to the National Center for Biotechnology Information (NCBI) GenBank, designated as NKT3 and the accession number is FJ230956. The phylogenetic analysis indicated that NKT3 is located at the branch of weak-inwardly rectifying K⁺ channels and might be a member of the Shaker family. The spatial and temporal expression of the gene was also investigated. NKT3 is expressed abundantly in the roots, while little in the leaves of N. tabacum. It might be involved in the process of K⁺ acquirement and release in tobacco roots.

Keywords: Potassium channel gene, NKT3, RACE, Nicotiana tabacum