Screening of key candidate regulatory pathways during the vegetative phase change in lily with short juvenile stage(短童期百合营养生长阶段转变的重要通路筛选)

Lily (Lilium spp.) is one of the most representative bulbous flowers. However, the vast majority of lilies have a long juvenile stage, which is a significant bottleneck for the development of the entire production industry. In this study, we analyzed the transition from the juvenile stage to the adult stage of different germplasms and bulblet sizes in lily. Furthermore, using the typical short-juvenile-stage germplasm L.×formolongi seedlings as materials, second-generation transcriptome sequencing was performed with shoot apical meristem (SAM) samples from the juvenile stage (0-4 months), transition stage (4-6 months) and adult stage (6-24 months) plants. The transcriptome data were assembled and annotated, and 15 172 differentially expressed genes were identified. Additionally, key candidate regulatory pathways involved in the transition from the juvenile stage to the adult stage of L.×formolongi, e.g., carbohydrate metabolism and regulation of post-embryonic development, were identified. Real-time fluorogenic quantitative polymerase chain reaction (qRT-PCR) was used to verify the expression patterns of six differentially expressed genes during the transition from the juvenile stage to the adult stage. The results showed that the expression trends of the selected genes at different developmental stages were basically consistent with the transcriptome sequencing results, with a coefficient of determination of 0.913 0, demonstrating the reliability of the gene expression data obtained from transcriptome sequencing. In conclusion, based on the use of specific high-quality resources, the generated transcriptome data reflecting the growth process of seedlings lay a foundation for the construction of co-expression networks and core gene mining in the future. . 百合（Lilium spp.）是最具代表性的球根花卉之一，但绝大多数百合存在童期长问题，已成为整个产业发展的重要瓶颈。本研究分析了不同种质与不同规格百合鳞茎童期转换情况，并以短童期新铁炮百合（Lilium×formolongi）实生苗为材料，取童期（0～4月）、转换期（4～6月）和成年期（6～24月）植株的茎顶端分生组织（shoot apical meristem, SAM）进行二代转录组测序，并对转录组数据进行组装和注释，结果共筛选到15 172个差异表达基因，同时挖掘出新铁炮百合从童期向成年期阶段转变的关键候选调控通路，如碳水化合物代谢及胚后发育调控等。利用实时荧光定量聚合酶链反应（real-time fluorogenic quantitative polymerase chain reaction, qRT-PCR）方法对6个差异表达基因在童期向成年期阶段转变过程中的表达模式进行验证，结果表明，所选基因在不同发育期的表达趋势与转录组测序结果基本一致，决定系数达0.913 0，证明转录组测序数据具有可靠性。本研究在利用特异性优质资源的基础上，以实生苗生长过程为基础开展的转录组测序可为后续共表达网络的构建和核心基因挖掘奠定数据基础。