Department of Horticulture, Shenyang Agricultural University, Shenyang, China.
Institute of Botany, Chinese Academy of Sciences, Beijing, China.
Sci Rep. 2021 May 25;11(1):10842. doi: 10.1038/s41598-021-90270-y.
Magnolia sieboldii K. Koch (M. sieboldii) is a deciduous Chinese tree species of the Magnoliaceae family with high ornamental, medicinal, and economic benefits. The germination of M. sieboldii seeds under natural conditions is extremely difficult, thereby hindering the cultivation and breeding of this important species. The molecular mechanisms underlying M. sieboldii seed germination remain unclear due to the lack of genomic and transcriptomic resources. Here, we integrated both mRNA and miRNA sequencing to identify the genes and pathways related to M. sieboldii germination. A comprehensive full-length transcriptome containing 158,083 high-quality unigenes was obtained by single-molecule real-time (SMRT) sequencing technology. We identified a total of 13,877 genes that were differentially expressed between non-germinated and germinated seeds. These genes were mainly involved in plant hormone signal transduction and diverse metabolic pathways such as those involving lipids, sugars, and amino acids. Our results also identified a complex regulatory network between miRNAs and their target genes. Taken together, we present the first transcriptome of M. sieboldii and provide key genes and pathways associated with seed germination for further characterization. Future studies of the molecular basis of seed germination will facilitate the genetic improvement M. sieboldii.
深山含笑（Magnolia sieboldii K. Koch）是木兰科含笑属落叶乔木，具有较高的观赏、药用和经济价值。其自然条件下种子萌发率极低，严重阻碍了该重要物种的栽培和繁殖。由于缺乏基因组和转录组资源，深山含笑种子萌发的分子机制尚不清楚。在这里，我们整合了 mRNA 和 miRNA 测序，以鉴定与深山含笑种子萌发相关的基因和途径。通过单分子实时（SMRT）测序技术获得了包含 158,083 个高质量的全长转录本的综合全长转录组。我们共鉴定出 13,877 个在未萌发和萌发种子之间差异表达的基因。这些基因主要参与植物激素信号转导以及脂质、糖和氨基酸等多种代谢途径。我们的研究结果还鉴定了 miRNA 和其靶基因之间的复杂调控网络。总之，我们首次构建了深山含笑的转录组，并提供了与种子萌发相关的关键基因和途径，为进一步研究奠定了基础。对种子萌发分子基础的研究将有助于深山含笑的遗传改良。
