Identification of cysteine-rich receptor-like kinase gene family in potato: revealed StCRLK9 in response to heat, salt and drought stresses.

The investigation into cysteine-rich receptor-like kinases (CRLKs) holds pivotal significance as these conserved, upstream signalling molecules intricately regulate fundamental biological processes such as plant growth, development and stress adaptation. This study undertakes a comprehensive characterisation of CRLKs in Solanum tuberosum (potato), a staple food crop of immense economic importance. Employing comparative genomics and evolutionary analyses, we identified 10 distinct CRLK genes in potato. Further categorisation into three major groups based on sequence similarity was performed. Each CRLK member in potato was systematically named according to its chromosomal position. Multiple sequence alignment and phylogenetic analyses unveiled conserved gene structures and motifs within the same groups. The genomic distribution of CRLKs was observed across Chromosomes 2-5, 8 and 12. Gene duplication analysis highlighted a noteworthy trend, with most gene pairs exhibiting a Ka/Ks ratio greater than one, indicating positive selection of StCRLKs in potato. Salt and drought stresses significantly impacted peroxidase and catalase activities in potato seedlings. The presence of diverse cis -regulatory elements, including hormone-responsive elements, underscored their involvement in myriad biotic and abiotic stress responses. Interestingly, interactions between the phytohormone auxin and CRLK proteins unveiled a potential auxin-mediated regulatory mechanism. A holistic approach combining transcriptomics and quantitative PCR validation identified StCRLK9 as a potential candidate involved in plant response to heat, salt and drought stresses. This study lays a robust foundation for future research on the functional roles of the CRLK gene family in potatoes, offering valuable insights into their diverse regulatory mechanisms and potential applications in stress management.