Genome-wide identification and expression analysis of wall-associated kinase (WAK) gene family in potato (Solanum tuberosum L.)

The wall-associated kinases (WAKs) and wall-associated kinase like (WAKL) play a vital regulating role in responses to diverse environment stresses and pathogenic microbes in plants. This experiment aims to predict the members, gene structure, subcellular and chromosomal localization, cis -acting elements, system evolution, selective pressure, docking analysis and expression of StWAK-RLK gene family by bioinformatics approaches. In total, 16 StWAK and 13 StWAKL genes were identified in potato genome. Six tandem gene clusters containing 21 members were found from StWAK-RLKs. Based on evolutionary tree analysis, we revealed the obvious evolutionary characteristics in plants. The Ka/Ks ratio of 15 collinearity gene pairs suggested that the StWAK-RLK gene family underwent a purifying selection. Cis -elements in the StWAK-RLKs promoter region mainly responded to plant hormones, flavonoid metabolite, biotic stresses, defense and stress signals. Based on qRT-PCR data analysis, 11 genes verified the prediction accuracy of cis -acting elements. The expressions of StWAK 1, 5, 6, 14, StWAKL 4 and StWAKL 13 were gradually upregulated with the increase in the Phytophthora infestans ( Pi ) infection time. The expressions of StWAK 2, 7, 8, 9, StWAKL 3 and 11were significantly induced under Pi inoculation. In addition, docking analyses showed that pectin had high binding affinity to StWAK9, StWAKL3, StWAKL4 and StWAKL11. This finding provides a vital regulation role in anti-stress signals in potato and provides a reference for the potential functional analysis and plant breeding of WAK-RLK genes in the future.