Genome-wide Identification, Evolution, and Expression Analysis of the KT/HAK/KUP Family in Pear

Here, we identified 20 K+ transporter genes in pear (P. bretschneideri) using genome-wide analysis. Their gene structure, chromosomal distribution, conserved motifs, phylogenetics, duplication events, and expression patterns were also examined. The results of phylogenetic analysis showed that PbrKT/HAK/KUP genes were clustered into three major groups (Groups Iâ III). Among the 20 PbrKT/HAK/KUP genes, 18 were mapped to nine chromosomes and two to scaffolds. Four WGD/segmental gene pairs have been identified, indicating that WGD/segmental duplicationmay have contributed to the expansion of KT/HAK/KUP family in pear. Among the four pairs of WGD/segmentally duplicated genes, both members of three pairs had been subjected to purifying selection, whereas the fourth pair had been subjected to positive selection. Furthermore, the phenotypic experiments showed that the growth of pear seedlings were affected by potassium deficiency treatment. Expression patterns of 20 PbrKT/HAK/KUP genesin roots were further assayed with qRT-PCR. The expression of PbrHAK1 and PbrHAK12/16 were significantly in response to K+ deficiency, suggesting that these genes are crucial for K+ uptake in pear, especially under the condition of K+ starvation. Our results provide a foundation for further studies on the function of KT/HAK/KUP genes in pear.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author