Because of the accumulation of heavy metals, Hydrilla verticillata (L.f.) Royle, a rooted submerged perennial aquatic herb, is being developed as a potential tool to clean the aquatic ecosystem polluted by heavy metals. However, its physiological responses for heavy metal remain to be elucidated. Here, through employing proteomics approach, we found that excess Cu significantly induced the expressions of four DNA methylation related proteins in H. verticillata, which were the homologues of two domains rearranged methyltransferases (DRM), a methyltransferases chromomethylase (CMT) and a histone H3 lysine-9 specific SUVH6-like (SUVH6). Consistently, a dramatic change in DNA methylation patterns was detected in excess Cu-exposed H. verticillata. Surprisingly, administration of the NADPH oxidase inhibitors, diphenylene iodonium (DPI) and imidazole (IMZ) that block production of reactive oxygen species (ROS) could trigger the remethylation of genomic sites that were demethylated by excess Cu, indicating that Cu-induced ROS might be another way to affect DNA methylation. Further analysis suggested this changed DNA methylation may be owing to the ROS-induced DNA damage. Taken together, our findings demonstrate that two different ways to influence DNA methylation in excess Cu-treated H. verticillata.

由于重金属的积累，一种多年生的多年生水生草本植物-黑藻（Hydrilla verticillata（Lf）Royle）正在被开发为清洁被重金属污染的水生生态系统的潜在工具。然而，其对重金属的生理反应仍有待阐明。在这里，通过蛋白质组学的方法，我们发现过量的铜显着诱导了网状线虫中四个DNA甲基化相关蛋白的表达，这是两个域重排的甲基转移酶（DRM），甲基转移酶色甲基化酶（CMT）和组蛋白H3的同源物。赖氨酸9特异的SUVH6样（SUVH6）。一致地，在过量的铜暴露的黄萎病菌中检测到DNA甲基化模式的显着变化。出人意料的是，阻断活性氧（ROS）产生的NADPH氧化酶抑制剂，联苯碘鎓（DPI）和咪唑（IMZ）的使用可能触发由过量Cu脱甲基的基因组位点的再甲基化，表明Cu诱导的ROS可能是影响DNA甲基化的另一种方法。进一步的分析表明，这种DNA甲基化的改变可能是由于ROS诱导的DNA损伤。综上所述，我们的发现表明，有两种不同的方法可以影响过量的铜处理过的H. verticillata中的DNA甲基化。