Beijing Engineering Research Center for Hybrid Wheat, The Municipal Key Laboratory of the Molecular Genetics of Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China.
Hebei Normal University, Shijiazhuang, 050024, China.
Planta. 2018 Jun;247(6):1307-1321. doi: 10.1007/s00425-018-2848-3. Epub 2018 Mar 5.
Transcriptome analysis was carried out for wheat seedlings and spikes from hybrid Jingmai 8 and both inbred lines to unravel mechanisms underlying heterosis. Heterosis, known as one of the most successful strategies for increasing crop yield, has been widely exploited in plant breeding systems. Despite its great importance, the molecular mechanism underlying heterosis remains elusive. In the present study, RNA sequencing (RNA-seq) was performed on the seedling and spike tissues of the wheat (Triticum aestivum) hybrid Jingmai 8 (JM8) and its homozygous parents to unravel the underlying mechanisms of wheat heterosis. In total, 1686 and 2334 genes were identified as differentially expressed genes (DEGs) between the hybrid and the two inbred lines in seedling and spike tissues, respectively. Gene Ontology analysis revealed that DEGs from seedling tissues were significantly enriched in processes involved in photosynthesis and carbon fixation, and the majority of these DEGs expressed at a higher level in JM8 compared to both inbred lines. In addition, cell wall biogenesis and protein biosynthesis-related pathways were also significantly represented. These results confirmed that a combination of different pathways could contribute to heterosis. The DEGs between the hybrid and the two inbred progenitors from the spike tissues were significantly enriched in biological processes related to transcription, RNA biosynthesis and molecular function categories related to transcription factor activities. Furthermore, transcription factors such as NAC, ERF, and TIF-IIA were highly expressed in the hybrid JM8. These results may provide valuable insights into the molecular mechanisms underlying wheat heterosis.
对杂种 Jingmai 8 及其两个自交系的小麦幼苗和穗进行转录组分析，以揭示杂种优势的潜在机制。杂种优势是提高作物产量最成功的策略之一，已广泛应用于植物育种系统。尽管杂种优势具有重要意义，但杂种优势的分子机制仍难以捉摸。本研究对小麦（Triticum aestivum）杂种 Jingmai 8（JM8）及其纯合亲本的幼苗和穗组织进行了 RNA 测序（RNA-seq），以揭示小麦杂种优势的潜在机制。在幼苗和穗组织中，杂种 JM8 与两个自交系之间分别鉴定出 1686 个和 2334 个差异表达基因（DEGs）。GO 分析表明，幼苗组织中的 DEGs 显著富集在光合作用和碳固定相关过程中，并且这些 DEGs 中的大多数在 JM8 中的表达水平高于两个自交系。此外，细胞壁生物发生和蛋白质生物合成相关途径也显著富集。这些结果证实，不同途径的组合可能有助于杂种优势。穗组织中杂种与两个自交系亲本之间的 DEGs 显著富集于转录、RNA 生物合成和与转录因子活性相关的分子功能类别相关的生物学过程。此外，NAC、ERF 和 TIF-IIA 等转录因子在杂种 JM8 中高度表达。这些结果可能为小麦杂种优势的分子机制提供有价值的见解。
