结论:建立了灯盏花稳定的遗传转化体系。我们克隆了EbYUC2基因,并将其遗传转化为拟南芥和灯盏细辛。叶子的编号,YUC2基因表达,转基因植株内源生长素含量显著增加。灯盏细辛是临床治疗心脑血管疾病的处方药。莲座叶的主要活性化合物灯盏细辛含量最高,是灯盏细辛产量的重要组成部分。然而,与灯盏细辛的叶数和开花时间相关的基因知之甚少。在我们之前的研究中,通过结合重测序数据和全基因组关联研究(GWAS),我们确定了3个与灯盏花叶数和开花相关的候选基因.然而,其特定功能仍有待表征。在这项研究中,我们克隆了先前鉴定的全长EbYUC2基因并将其转化到拟南芥中,开发了第一个稳定的灯盏细辛遗传转化系统,并获得过表达EbYUC2的转基因植株。与野生型植物相比,转基因植物的叶片数量显着增加,这与EbYUC2的表达增加有关。始终如一,内源性生长素含量,特别是吲哚-3-乙酸,在转基因植物中也显著增加。这些结果表明,EbYUC2可能通过调节生长素的生物合成来控制叶片数量,从而为揭示灯盏花叶数和开花时间的分子机制奠定了基础。
CONCLUSIONS: A stable genetic transformation system for Erigeron breviscapus was developed. We cloned the EbYUC2 gene and genetically transformed it into Arabidopsis thaliana and E. breviscapus. The leaf number, YUC2 gene expression, and the endogenous auxin content in transgenic plants were significantly increased. Erigeron breviscapus is a prescription drug for the clinical treatment of cardiovascular and cerebrovascular diseases. The rosette leaves have the highest content of the major active compound scutellarin and are an important component in the yield of E. breviscapus. However, little is known about the genes related to the leaf number and flowering time of E. breviscapus. In our previous study, we identified three candidate genes related to the leaf number and flowering of E. breviscapus by combining resequencing data and genome-wide association study (GWAS). However, their specific functions remain to be characterized. In this study, we cloned and transformed the previously identified full-length EbYUC2 gene into Arabidopsis thaliana, developed the first stable genetic transformation system for E. breviscapus, and obtained the transgenic plants overexpressing EbYUC2. Compared with wild-type plants, the transgenic plants showed a significant increase in the number of leaves, which was correlated with the increased expression of EbYUC2. Consistently, the endogenous auxin content, particularly indole-3-acetic acid, in transgenic plants was also significantly increased. These results suggest that EbYUC2 may control the leaf number by regulating auxin biosynthesis, thereby laying a foundation for revealing the molecular mechanism governing the leaf number and flowering time of E. breviscapus.