薄壳山核桃是世界著名干果和重要木本油料树种，由于其营养生长期长导致开花结实晚、产量低，严重制约产业发展。为提高薄壳山核桃产出及效益，亟需调控营养生长与生殖生长的平衡关系，促使营养生长转化为生殖生长（成花转变），启动成花因子表达，促进花芽分化。申请人通过转录组和sRNA测序联合分析，筛选到3个成花转变关键基因（CiSPL5/16/19）。拟南芥SPL调控MADS-box基因参与成花转变，但薄壳山核桃SPL转录因子的作用尚不明晰。本研究拟利用过量表达和突变体互补实验对CiSPLs基因进行功能鉴定；分析CiSPLs基因在花芽各阶段、成花诱导期不同处理下表达模式；GUS活性检测研究CiSPLs基因启动子表达特性；凝胶阻滞实验验证CiSPLs与MADS-box基因启动子相互作用。本研究有助于阐明SPL转录因子在薄壳山核桃成花转变过程中的作用机制，对促进提早开花、加快育种进程具有重要理论和实践意义。

Pecan is a world famous dry fruit and woody oil tree species, because of its long vegetative growth period, it has late flowering and low yield, which seriously restricts the development of industry. In order to improve the yield and benefit of pecan, it is necessary to regulate the balance between vegetative growth and reproductive growth, promote vegetative growth into reproductive growth (floral transformation), initiate the expression of flowering factors and promote flower bud differentiation. The applicant screened three key genes of floral transformation (CiSPL5 /16/19) through conjoint analysis of transcriptome and sRNA sequencing. SPL regulates MADS-box genes involved in floral transformation in Arabidopsis, but the role of SPL transcription factor in pecan is still unclear. The study intends to identify the function of CiSPLs by overexpression and mutant complementation; analyze the expression pattern of CiSPLs in different stages of flower bud development, and that in different treatments during flower induction; evaluate the expression characteristics of CiSPLs genes promoter by GUS activity assay; confirm the interaction between CiSPLs and MADS-box genes promoter by gel retardation assay. This study is helpful to elucidate the mechanism of SPL transcription factor in the process of pecan flower transformation, and has important theoretical and practical significance in promoting early flowering and accelerating the breeding process.