Guo Hongwei, Zhang Guoyan, Zhou Min, Wan Min, Zhu Bo, Yang Zujun, Zeng Deying, Zeng Zixian
Department of Biological Science, College of Life Sciences, Sichuan Normal University, Chengdu, Sichuan, China.
Horticulture Institute, Sichuan Academy of Agricultural Sciences, Chengdu, China.
Front Genet. 2023 Jul 25;14:1241201. doi: 10.3389/fgene.2023.1241201. eCollection 2023.
Polyploidization plays important roles in the evolution and breeding of the common wheat. , the D-genome progenitor of the common wheat, provides a valuable pool of resistance genes to multiple diseases. Extensive studies focus on the exploration of these genes for wheat improvement. However, few studies have unveiled alternations on genome-wide expression pattern and histone modifications induced by whole-genome doubling (WGD) process. In this study, we conducted transcriptome analysis for the diploid and tetraploid lines using the leaf and root tissues. Both lines tend to display similar tissue-specific pattern. Interestingly, we found that TEs located in genic regions were depleted of the repressive histone mark H3K27me3, whereas their adjacent chromatin was enriched with H3K27me3. The tetraploid line exhibited higher levels of H3K27me3 in those regions than the diploid line, particularly for genic regions associated with TEs of the long interspersed nuclear elements (LINEs), CACTA, PIF/Harbinger, Tc1/Mariner and unclassed DNA transposon. Surprisingly, the expression levels of these TEs cognate genes were negatively associated with the levels of H3K27me3 between the tetraploid and diploid lines, suggesting the five types of TEs located within genic regions might be involved in the regulation of the ploidy-related gene expression, possibly through differential enrichment of H3K27me3 in the genic regions. These findings will help to understand the potential role of specific types of TEs on transcription in response to WGD.
多倍体化在普通小麦的进化和育种中发挥着重要作用。普通小麦的D基因组祖先为多种疾病提供了宝贵的抗性基因库。广泛的研究致力于探索这些基因以改良小麦。然而，很少有研究揭示全基因组加倍（WGD）过程诱导的全基因组表达模式和组蛋白修饰的变化。在本研究中，我们使用叶片和根组织对二倍体和四倍体系进行了转录组分析。两个体系都倾向于表现出相似的组织特异性模式。有趣的是，我们发现位于基因区域的转座元件（TEs）缺乏抑制性组蛋白标记H3K27me3，而其相邻染色质富含H3K27me3。四倍体系在这些区域表现出比二倍体系更高水平的H3K27me3，特别是对于与长散在核元件（LINEs）、CACTA、PIF/Harbinger、Tc1/Mariner和未分类DNA转座子的TEs相关的基因区域。令人惊讶的是，这些TEs同源基因的表达水平与四倍体和二倍体体系之间的H3K27me3水平呈负相关，表明位于基因区域内的五种类型的TEs可能参与了倍性相关基因表达的调控，可能是通过基因区域中H3K27me3的差异富集。这些发现将有助于理解特定类型的TEs在响应WGD时对转录的潜在作用。
