Peony International Institute, Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education, School of Landscape Architecture, Beijing Forestry University, Beijing, 100083, China.
BMC Genomics. 2019 Aug 29;20(1):683. doi: 10.1186/s12864-019-6036-z.
Quantitative variation of floral organs in plants is caused by an extremely complex process of transcriptional regulation. Despite progress in model plants, the molecular mechanisms of quantitative variation remain unknown in woody flower plants. The Paeonia rockii originated in China is a precious woody plant with ornamental, medicinal and oil properties. There is a wide variation in the number of carpel in P. rockii, but the molecular mechanism of the variation has rarely been studied. Then a comparative transcriptome was performed among two cultivars of P. rockii with different development patterns of carpel in this study.
Through the next-generation and single-molecule long-read sequencing (NGS and SMLRS), 66,563 unigenes and 28,155 differentially expressed genes (DEGs) were identified in P. rockii. Then clustering pattern and weighted gene coexpression network analysis (WGCNA) indicated that 15 candidate genes were likely involved in the carpel quantitative variation, including floral organ development, transcriptional regulatory and enzyme-like factors. Moreover, transcription factors (TFs) from the MYB, WD, RING1 and LRR gene families suggested the important roles in the management of the upstream genes. Among them, PsMYB114-like, PsMYB12 and PsMYB61-like from the MYB gene family were probably the main characters that regulated the carpel quantitative variation. Further, a hypothetical model for the regulation pattern of carpel quantitative variation was proposed in which the candidate genes function synergistically the quantitative variation process.
We present the high-quality sequencing products in P. rockii. Our results summarize a valuable collective of gene expression profiles characterizing the carpel quantitative variation. The DEGs are candidate for functional analyses of genes regulating the carpel quantitative variation in tree peonies, which provide a precious resource that reveals the molecular mechanism of carpel quantitative variation in other woody flower crops.
植物花器官的数量变化是由转录调控的一个极其复杂的过程引起的。尽管在模式植物中取得了进展，但木质花卉植物的数量变化的分子机制仍不清楚。原产于中国的牡丹是一种具有观赏、药用和油用价值的珍贵木本植物。牡丹的花瓣数量存在广泛的变异，但变异的分子机制很少被研究。本研究中，对两个具有不同花瓣发育模式的牡丹品种进行了比较转录组分析。
通过下一代和单分子长读测序（NGS 和 SMLRS），在牡丹中鉴定出 66563 个 unigenes 和 28155 个差异表达基因（DEGs）。然后聚类模式和加权基因共表达网络分析（WGCNA）表明，15 个候选基因可能参与了花瓣数量的变化，包括花器官发育、转录调控和酶样因子。此外，来自 MYB、WD、RING1 和 LRR 基因家族的转录因子（TFs）表明它们在管理上游基因方面的重要作用。其中，来自 MYB 基因家族的 PsMYB114-like、PsMYB12 和 PsMYB61-like 可能是调控花瓣数量变化的主要特征。此外，提出了一个花瓣数量变化调控模式的假设模型，其中候选基因协同作用于数量变化过程。
我们在牡丹中呈现了高质量的测序产物。我们的结果总结了一个有价值的基因表达谱集合，这些基因表达谱特征描述了花瓣数量的变化。这些差异表达基因是调控牡丹花瓣数量变化基因的功能分析的候选基因，为揭示其他木本花卉作物花瓣数量变化的分子机制提供了宝贵的资源。
