Identification of Shaker K+ channel family members in Rosaceae and a functional exploration of PbrKAT1
PbrKAT1, which is inhibited by external Na+ in Xenopus laevis oocytes, is characterized as encoding a typical inward rectifying channel that is mainly expressed in guard cells.
Potassium (K+) is the most abundant cation in plant cells necessary for plant growth and development. The uptake and transport of K+ are mainly completed through transporters and channels, and the Shaker family genes are the most studied K+ channels in plants. However, there is far less information about this family in Rosaceae species. We performed a genome-wide analysis and identified Shaker K+ channel gene family members in Rosaceae. We cloned and characterized a Shaker K+ channel KAT1 from pear (Pyrus × bretschneideri). In total, 36 Shaker K+ channel genes were identified from Rosaceae species and were classified into five subgroups based on structural characteristics and a phylogenetic analysis. Whole-genome and dispersed duplications were the primary forces underlying Shaker K+ channel gene family expansion in Rosaceae, and purifying selection played a key role in the evolution of Shaker K+ channel genes. β-Glucuronidase and qRT-PCR assays revealed that PbrKAT1 was mainly expressed in leaves, especially in guard cells. PbrKAT1 displayed a typical inward-rectifying current when expressed in Xenopus laevis oocytes. The activity of PbrKAT1 was inhibited by external sodium ions, possibly playing an important role in the regulation of salt tolerance in pear. These results provide valuable information on evolution, expression and functions of the Shaker K+ channel gene family in plants.
KeywordsNa+ inhibition Pear Potassium Stomata Voltage-clamp technique
The inward rectifying K+
Whole Genome Duplication
This work was supported by the Fundamental Research Funds for the Central Universities (KJQN201926), National Natural Science Foundation of China (31801842, 31772256), and the National Key R&D Program of China (2018YFD0201400).
Compliance with ethical standards
The authors declare that no competing interests exist.
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