Identification and expression analysis of cinnamyl CoA reductase gene family and function of StCCR6 in potato (Solanum tuberosum L.)

Cinnamoyl-CoA reductase (CCR), a key rate-limiting enzyme in plant lignin biosynthesis, critically regulates plant growth, development, and abiotic stress responses. As one of the world's four major staple crops, potato (<i>Solanum tuberosum</i> L.) is extensively cultivated due to its nutritional value and versatile applications, underscoring the importance of investigating the <i>StCCR</i> gene family and its expression patterns under abiotic stress. In this study, we identified 10 <i>CCR</i> genes from the Atlantic potato genome and conducted comprehensive analyses of their phylogenetic relationships, gene structures, species collinearity, cis-regulatory elements, and expression specificity. Virus-induced gene silencing (VIGS) was used to silence <i>StCCR6</i>, resulting in altered lignin content and enhanced susceptibility to bacterial infection. Results revealed structural and functional divergences among <i>StCCRs</i> members. Tissue-specific expression profiling demonstrated higher transcript abundance in stems and leaves compared to roots. Notably, <i>StCCRs</i> exhibited differential expression patterns across multiple stress conditions, with Subfamily I genes showing consistent upregulation under various treatments, suggesting their potential as core candidates mediating stress-responsive lignification. Silencing of <i>StCCR6</i> altered lignin content and cell wall structure in potato, and the oxidative damage was more serious after bacterial infection. These findings establish a foundation for elucidating the functional roles of <i>StCCRs</i> in potato growth regulation and stress adaptation mechanisms.