The potential role of short internodes/stylish (SHI/STY) and SHI related sequence (SRS) in potato tuberization

BACKGROUND SRS: (Short Internodes/Stylish/SHI-Related Sequence) genes play a crucial role in plant developments, encompassing organ morphogenesis. However, at present, the biological significance of potato StSRS genes remains unknown. This study comprehensively identified and analysed the potential functions of StSRS genes in potato tuberization. RESULTS: Through phylogenetic and conserved motif analyses, eight members of the StSRS family were successfully identified and classified into five distinct subfamilies. The intraspecies and interspecies collinearity analyses offered insights into the evolutionary clues of the StSRS family, showing closer homology to tomato and tobacco. High-quality RNA-sequencing (Q30 > 97.16%) revealed dynamic gene expression profiles, with 146 to 997 differentially expressed transcription factors (DETFs), particularly from the MYB-related, GATA, and bHLH families. Among them, the expression of two StSRS genes, StSRS1 and StSRS8, were dramatically changed during potato tuber formation. Weighted Gene Co-expression Network Analysis (WGCNA) uncovered stage-specific gene modules and spotlighted hub genes. Specifically, StSRS8 was strongly associated with the Stolon stage, while StSRS1 was evidently linked to the Tuber stage. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis revealed that the transcripts of both StSRS1 and StSRS8 were predominantly expressed during potato tuberization, as compared to those in other tissues. However, it is scarcely detectable for other six StSRS genes. Furthermore, the transcripts of StSRS8 were repressed under short-day (SD) conditions. CONCLUSION: These findings yield critical insights into the potato StSRS gene family and furnish essential information for further function investigation of StSRS genes, particularly StSRS1 and StSRS8, in the context of potato tuberization.