College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China.
College of Agriculture/Tree Peony, Henan University of Science and Technology, Luoyang, Henan sheng, China.
Plant Signal Behav. 2022 Dec 31;17(1):2056364. doi: 10.1080/15592324.2022.2056364.
Tree peony is a famous flower plant in China, but the short and concentrated flowering period limits its ornamental value and economic value. Brassinolide (BR) plays an important role in plant growth and development including flowering. There have been a large number of reports on the molecular aspects of the flowering process, but the genetic mechanism that was responsible for miRNA-guided regulation of tree peony is almost unclear. In this study, the leaves of tree peony cultivar, 'Feng Dan', were sprayed with different concentrations of BR, and the obvious bloom delay was found at the treatment with BR 50 μg/L. The small RNA sequencing and transcriptome sequencing were performed on the petals of tree peony under an untreated control (CK) and the treatment with BR 50 μg/L during four consecutive flowering development stages. A total of 22 known miRNAs belonging to 12 families were identified and 84 novel miRNAs were predicted. Combined with transcriptome data, a total of 376 target genes were predicted for the 18 differentially expressed known miRNAs and 177 target genes were predicted for the 23 differentially expressed novel miRNAs. Additionally, the potential miRNAs and their target genes were identified, including miR156b targeting , miR172a_4 targeting and four novel miRNAs targeting , and revealed that they might affect the flowering time in tree peony. Collectively, these results would provide a theoretical basis for further analysis of miRNA-guided regulation on flowering period in tree peony.
牡丹是中国著名的花卉植物，但短而集中的花期限制了其观赏价值和经济价值。油菜素内酯（BR）在植物的生长发育中起着重要的作用，包括开花。关于开花过程的分子方面已经有大量的报道，但负责牡丹 miRNA 指导调控的遗传机制几乎不清楚。本研究中，对牡丹品种‘凤丹’的叶片喷施不同浓度的 BR，发现 BR 50μg/L 处理时开花明显延迟。在未处理对照（CK）和 BR 50μg/L 处理下的四个连续开花发育阶段，对牡丹花瓣进行了小 RNA 测序和转录组测序。共鉴定出 22 个已知 miRNA 家族的 miRNA，预测出 84 个新的 miRNA。结合转录组数据，共预测出 18 个差异表达已知 miRNA 的 376 个靶基因和 23 个差异表达新 miRNA 的 177 个靶基因。此外，还鉴定出了潜在的 miRNA 及其靶基因，包括 miR156b 靶向 、miR172a_4 靶向 和四个新的 miRNA 靶向 ，表明它们可能影响牡丹的开花时间。综上所述，这些结果为进一步分析牡丹开花时间的 miRNA 指导调控提供了理论依据。
