Genome-Wide Identification and Analysis of HAK/KUP/KT Potassium Transporters Gene Family in Wheat ( Triticum aestivum L.)

In plants, the HAK (high-affinity K⁺)/KUP (K⁺ uptake)/KT (K⁺ transporter) family represents a large group of potassium transporters that play important roles in plant growth and environmental adaptation. Although genes have been extensively investigated in many plant species, they remain uncharacterized in wheat, especially those involved in the response to environmental stresses. In this study, 56 wheat (hereafter called s) genes were identified by a genome-wide search using recently released wheat genomic data. Phylogenetic analysis grouped these genes into four clusters (Ι, II, III, IV), containing 22, 19, 7 and 8 genes, respectively. Chromosomal distribution, gene structure, and conserved motif analyses of the 56 genes were subsequently performed. In silico RNA-seq data analysis revealed that s from clusters II and III are constitutively expressed in various wheat tissues, while most genes from clusters I and IV have very low expression levels in the examined tissues at different developmental stages. qRT-PCR analysis showed that expression levels of genes in wheat seedlings were significantly up- or downregulated when seedlings were exposed to K⁺ deficiency, high salinity, or dehydration. Furthermore, we functionally characterized and showed that it facilitates K⁺ transport in yeast. Collectively, these results provide valuable information for further functional studies of , and contribute to a better understanding of the molecular basis of wheat development and stress tolerance.