Isolation and Functional Determination of SKOR Potassium Channel in Purple Osier Willow, Salix purpurea

Yahui Chen; Xuefeng Peng; Jijie Cui; Hongxia Zhang; Jiang Jiang; Zhizhong Song

doi:10.1155/2021/6669509

Isolation and Functional Determination of SKOR Potassium Channel in Purple Osier Willow, Salix purpurea

Int J Genomics. 2021 Feb 25:2021:6669509. doi: 10.1155/2021/6669509. eCollection 2021.

Authors

Yahui Chen^#^{1

2

3

4}, Xuefeng Peng^#^{2

4}, Jijie Cui^#^{2

4}, Hongxia Zhang^{2

4}, Jiang Jiang^{1

3

4}, Zhizhong Song^{1

2

4

5}

Affiliations

¹ Collaborative Innovation Center of Sustainable Forestry in Southern China of Jiangsu Province, Nanjing Forestry University, Nanjing, Jiangsu, China.
² The Engineering Research Institute of Agriculture and Forestry, Ludong University, Yantai, Shandong, China.
³ Molecular Testing Laboratory of New Plant Varieties in Southern China of State Forestry Administration, Nanjing, Jiangsu, China.
⁴ Key Laboratory of Molecular Module-Based Breeding of High Yield and Abiotic Resistant Plants in Universities of Shandong (Ludong University), Yantai, Shandong, China.
⁵ Department of Plant Science, University of Cambridge, Cambridge CB2 3EA, UK.

^# Contributed equally.

Abstract

Potassium (K⁺) plays key roles in plant growth and development. However, molecular mechanism studies of K⁺ nutrition in forest plants are largely rare. In plants, SKOR gene encodes for the outward rectifying Shaker-type K⁺ channel that is responsible for the long-distance transportation of K⁺ through xylem in roots. In this study, we determined a Shaker-type K⁺ channel gene in purple osier (Salix purpurea), designated as SpuSKOR, and determined its function using a patch clamp electrophysiological system. SpuSKOR was closely clustered with poplar PtrSKOR in the phylogenetic tree. Quantitative real-time PCR (qRT-PCR) analyses demonstrated that SpuSKOR was predominantly expressed in roots, and expression decreased under K⁺ depletion conditions. Patch clamp analysis via HEK293-T cells demonstrated that the activity of the SpuSKOR channel was activated when the cell membrane voltage reached at -10 mV, and the channel activity was enhanced along with the increase of membrane voltage. Outward currents were recorded and induced in response to the decrease of external K⁺ concentration. Our results indicate that SpuSKOR is a typical voltage dependent outwardly rectifying K⁺ channel in purple osier. This study provides theoretical basis for revealing the mechanism of K⁺ transport and distribution in woody plants.