属于ATP依赖的染色质重塑因子的SHPRH（SNF2，组蛋白连接器，PHD，RING，解旋酶）亚家族是有效的肿瘤抑制因子，可以使细胞增殖核抗原（PCNA）发生多泛素化并参与人类的后复制修复。然而，有关SHPRH蛋白在植物中的功能了解甚少。在这项研究中，我们鉴定了一个新的SHPRH成员BrCHR39并获得了BrCHR39沉默转基因油菜。与野生型植物相比，转基因油菜表现出半矮化和多侧枝的释放顶端优势表型。此外，在沉默BrCHR39后，主茎和芽的DNA甲基化发生了全局性变化。根据GO（基因本体论）功能注释和KEGG（基因组学百科全书）通路分析，植物激素信号传导通路明显富集。特别是，在茎中，生长素相关基因的甲基化水平显著增加，而转基因植物的芽中生长素和细胞分裂素相关基因的甲基化水平降低。此外，进一步的qRT-PCR（定量实时PCR）分析揭示，DNA甲基化水平总是与基因表达水平呈相反趋势。综合考虑，我们的发现表明，抑制BrCHR39表达会触发激素相关基因的甲基化差异，随后影响转录水平以调节油菜的顶端优势。

The SHPRH (SNF2, histone linker, PHD, RING, helicase) subfamily belonging to ATP-dependent chromatin remodeling factor is the effective tumor-suppressor, which can polyubiquitinate PCNA (proliferating cell nuclear antigen) and participate in post-replication repair in human. However, little is known about the functions of SHPRH proteins in plants. In this study, we identified a novel SHPRH member BrCHR39 and obtained BrCHR39-silenced transgenic Brassica rapa. In contrast to wild-type plants, transgenic Brassica plants exhibited a released apical dominance phenotype with semi-dwarfism and multiple lateral branches. Furthermore, a global alteration of DNA methylation in the main stem and bud appeared after silencing of BrCHR39. Based on the GO (gene ontology) functional annotation and KEGG (Kyoto encyclopedia of genes and genomes) pathway analysis, the plant hormone signal transduction pathway was clearly enriched. In particular, we found a significant increase in the methylation level of auxin-related genes in the stem, whereas auxin- and cytokinin-related genes were hypomethylated in the bud of transgenic plants. In addition, further qRT-PCR (quantitative real-time PCR) analysis revealed that DNA methylation level always had an opposite trend with gene expression level. Considered together, our findings indicated that suppression of BrCHR39 expression triggered the methylation divergence of hormone-related genes and subsequently affected transcription levels to regulate the apical dominance in Brassica rapa.