Asymmetric epigenome maps of subgenomes reveal imbalanced transcription and distinct evolutionary trends in Brassica napus
Asymmetric epigenome maps of subgenomes reveal imbalanced transcription and distinct evolutionary trends in Brassica napus
复制标题
DOI：
10.1016/j.molp.2020.12.020
复制
发表时间：
2020
期刊：
影响因子：
27.5
通讯作者：
Jinxiong Shen
中科院分区：
文献类型：
--
作者：
Qing Zhang;Pengpeng Guan;Lun Zhao;Meng Ma;Liang Xie;Yue Li;Ruiqin Zheng;Weizhi Ouyang;Shunyao Wang;Hongmeijuan Li;Ying Zhang;Yong Peng;Zhilin Cao;Wei Zhang;Qin Xiao;Yuanling Xiao;Tingdong Fu;Guoliang Li;Xingwang Li;Jinxiong Shen
The complexity of epigenome landscape and transcriptional regulation is significantly increased during plant polyploidy, which drives genome evolution and contributes to the increased adaptability to diverse environments. However, the comprehensive epigenomic mapping of Brassica napus remains unexplored. In this study, we performed integrative analysis of five histone modifications, RNA polymerase II occupancy, DNA methylation, and transcriptomes in two B. napus lines (2063A and B409), and established global maps of regulatory elements, chromatin states and their dynamics for the whole genome (including the An and Cn subgenomes) of four tissue types (young leaf, flower bud, silique, and root) of these two lines. Approximately 65.8% of the genome was annotated with different epigenomic signals. Compared to Cn subgenome, An subgenome possess higher level of active epigenetic marks and lower level of repressive epigenetic marks. Genes from subgenome-unique regions contribute to the major differences between the An and Cn subgenomes. Asymmetric histone modifications between homeologous gene pairs reflect their biased expression trends. We identified a novel bivalent chromatin state (with H3K4me1 and H3K27me3) in B. napus and suggest its key role in regulating tissue-specific gene expression. Furthermore, we observed that different types of duplicated genes have discrepant patterns of histone modification and DNA methylation levels. Collectively, our findings provide valuable epigenetic resources for the allopolyploid plants.
