Construction of a Yeast Two-Hybrid Library for Lilium × formolongi and Screening for Proteins Interacting with LfSVP

The MADS-box transcription factor SHORT VEGETATIVE PHASE (SVP) plays a pivotal role in flowering regulation. In this study, we aimed to elucidate the protein interaction network of LfSVP in Lilium × formolongi. A high-quality yeast two-hybrid (Y2H) cDNA library was constructed and screened using LfSVP as bait. From an initial pool of 18 candidate interactors, six proteins were confirmed through pairwise Y2H assays. These include known floral regulators APETALA1 (AP1), JASMONATE ZIM-DOMAIN (JAZ), SEUSS (SEU), and E3 ubiquitin-protein ligase ARI8 (ARI8), as well as stress-associated factors WRKY5 and SENSITIVE TO PROTON RHIZOTOXICITY1 (STOP1). Notably, virus-induced gene silencing (VIGS) demonstrated that LfSVP cooperates with LfAP1 to regulate floral organ development. While these findings suggest potential roles for LfSVP in flower development pathway, further functional validation is required in planta to establish the biological relevance of most interactions identified here. This work provides a potentially foundational interaction network for LfSVP and highlights candidates for future functional studies in lily flowering regulation.