Basic Research Plan of Shanxi Province Natural Science Research Project ( 20210302123390 ) ; Shanxi Province Modern Agricultural Chinese Herbal Medicine Industry Technology System Project ( 2023 )； Shanxi Agricultural University Science and Technology Innovation Promotion Project ( CXGC2023041 ) ; Innovation and Entrepreneurship Training Program for College Students in Shanxi Province ( 20220172 )
摘 要：目的 连翘Forsythia suspensa (Thunb.) Vahl为多年生木本植物，花柱二型具有自交不亲和性。挖掘连翘异型花柱发育候选基因，利于揭示连翘异型花柱的进化与发育机理。方法 本试验对40株长花柱型与短花柱型连翘植株进行全基因组重测序，检测样本基因组的SNP变异位点，开展选择清除分析。利用群体分化指数（Fst）和核酸多态性（θπ）结合的方法筛选候选区域（top 5%水平），对差异基因进行GO数据库和KEGG数据库功能注释分析，采用qRT-PCR对候选基因在花柱发育不同时期的表达量进行检测。结果 选择清除分析显示受选择基因295个，主要在植物的生长发育以及代谢调控方面发挥重要作用。分析植物激素调节相关的部分通路，确定连翘异型花柱候选基因CYP734A1（EVM0010386）、BRI1（EVM0011829）、CYCD3（EVM0018316），基因表达结果显示CYP734A1基因在连翘短花柱发育的关键时期持续高表达，露冠期BRI1与CYCD3基因表达水平在短花柱型中显著高于长花柱型。结论 本研究挖掘的候选基因在连翘长花柱与短花柱中存在差异表达，油菜素甾醇（BR）参与了连翘异型花柱的发育，是产生连翘花柱异型的原因之一。本研究为连翘异型花柱的进化以及遗传发育调控机制奠定基础并提供思路。
Abstract: Objective Forsythia suspensa ( Thunb. ) Vahl is a perennial woody plant with dimorphic style and self-incompatibility. Mining the candidate genes for the development of heterostyly in Forsythia suspensa is beneficial to reveal its evolution and development mechanism. Methods The whole genome resequencing of 40 long style morph and short style morph Forsythia suspensa plants were conducted, detected the SNP variation sites in the sample genome, and carry out selection sweep analysis. The candidate regions (top 5% level) were screened by the combination of population differentiation index (Fst) and nucleic acid polymorphism (θπ). Differential genes were analyzed by GO database and KEGG database functional annotation, and qRT-PCR was used to detect the expression of candidate genes at different periods of style development. Results Selective sweep analysis showed that 295 genes were selected, which mainly played an important role in plant growth and development and metabolic regulation. Some pathways related to plant hormone regulation were selected to determine the candidate genes CYP734A1 (EVM0010386), BRI1 (EVM0011829) and CYCD3 (EVM0018316) of heterostyly in Forsythia suspensa. The gene expression results indicate that the CYP734A1 gene has sustained high expression during the critical period of development in F. suspensa 's S-morph flowers. The BRI1 and CYCD3 genes in the S-morph were significantly higher than those in the L-morph during the crown exposure period. Conclusion The candidate genes excavated in this study were differentially expressed in the L-morph and S-morph style of F. suspensa. Brassinosteroids was involved in the development of the heterostyly in F. suspensa, which was one of the reasons for heterostyly of F. suspensa. This study laid a foundation for the evolution and genetic development regulation mechanism of heterostyly in F. suspensa.