Identification and Characterization of LRR-RLK Family Genes in Potato Reveal Their Involvement in Peptide Signaling of Cell Fate Decisions and Biotic/Abiotic Stress Responses

Leucine-rich repeat receptor-like kinases (LRR-RLKs) represent the largest subfamily of receptor-like kinases (RLKs) and play important roles in regulating growth, development, and stress responses in plants. In this study, 246 LRR-RLK genes were identified in the potato (Solanum tuberosum) genome, which were further classified into 14 subfamilies. Gene structure analysis revealed that genes within the same subgroup shared similar exon/intron structures. A signature small peptide recognition motif (RxR) was found to be largely conserved within members of subfamily IX, suggesting that these members may recognize peptide signals as ligands. 26 of the 246 StLRR-RLK genes were found to have arisen from tandem or segmental duplication events. Expression profiling revealed that StLRR-RLK genes were differentially expressed in various organs/tissues, and several genes were found to be responsive to different stress treatments. Furthermore, StLRR-RLK117 was found to be able to form homodimers and heterodimers with StLRR-RLK042 and StLRR-RLK052. Notably, the overlapping expression region of StLRR-RLK117 with Solanum tuberosum WUSCHEL (StWUS) suggested that the CLV3–CLV1/BAM–WUS feedback loop may be conserved in potato to maintain stem cell homeostasis within the shoot apical meristem.