Li Shu-Fen, Lv Can-Can, Lan Li-Na, Jiang Kai-Lu, Zhang Yu-Lan, Li Ning, Deng Chuan-Liang, Gao Wu-Jun
College of Life Sciences, Henan Normal University, Xinxiang, 453007, China.
Hortic Res. 2021 Sep 1;8(1):198. doi: 10.1038/s41438-021-00633-9.
DNA methylation is a crucial regulatory mechanism in many biological processes. However, limited studies have dissected the contribution of DNA methylation to sexual differentiation in dioecious plants. In this study, we investigated the variances in methylation and transcriptional patterns of male and female flowers of garden asparagus. Compared with male flowers, female flowers at the same stages showed higher levels of DNA methylation. Both male and female flowers gained DNA methylation globally from the premeiotic to meiotic stages. Detailed analysis revealed that the increased DNA methylation was largely due to increased CHH methylation. Correlation analysis of differentially expressed genes and differentially methylated regions suggested that DNA methylation might not have contributed to the expression variation of the sex-determining genes SOFF and TDF1 but probably played important roles in sexual differentiation and flower development of garden asparagus. The upregulated genes AoMS1, AoLAP3, AoAMS, and AoLAP5 with varied methylated CHH regions might have been involved in sexual differentiation and flower development of garden asparagus. Plant hormone signaling genes and transcription factor genes also participated in sexual differentiation and flower development with potential epigenetic regulation. In addition, the CG and CHG methylation levels in the Y chromosome were notably higher than those in the X chromosome, implying that DNA methylation might have been involved in Y chromosome evolution. These data provide insights into the epigenetic modification of sexual differentiation and flower development and improve our understanding of sex chromosome evolution in garden asparagus.
DNA甲基化是许多生物过程中的关键调控机制。然而，剖析DNA甲基化对雌雄异株植物性别分化贡献的研究有限。在本研究中，我们调查了芦笋雄花和雌花甲基化和转录模式的差异。与雄花相比，相同发育阶段的雌花显示出更高水平的DNA甲基化。从减数分裂前到减数分裂阶段，雄花和雌花的DNA甲基化整体上都有所增加。详细分析表明，DNA甲基化增加主要是由于CHH甲基化增加所致。差异表达基因与差异甲基化区域的相关性分析表明，DNA甲基化可能对性别决定基因SOFF和TDF1的表达变异没有贡献，但可能在芦笋的性别分化和花发育中起重要作用。具有不同甲基化CHH区域的上调基因AoMS1、AoLAP3、AoAMS和AoLAP5可能参与了芦笋的性别分化和花发育。植物激素信号基因和转录因子基因也通过潜在的表观遗传调控参与了性别分化和花发育。此外，Y染色体上的CG和CHG甲基化水平明显高于X染色体，这意味着DNA甲基化可能参与了Y染色体的进化。这些数据为性别分化和花发育的表观遗传修饰提供了见解，并增进了我们对芦笋性染色体进化的理解。
