Department of Biology, Ecology and Earth Science, University of Calabria, Ponte P. Bucci - 87036, Arcavacata di Rende, Cosenza, Italy.
Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Viale delle Scienze 11/A - 43124, Parma, Italy.
Plant Sci. 2020 Dec;301:110680. doi: 10.1016/j.plantsci.2020.110680. Epub 2020 Sep 17.
DNA methylation is a very important epigenetic modification that participates in many biological functions. Although many researches on DNA methylation have been reported in various plant species, few studies have assessed the global DNA methylation pattern in algae. Even more the complex mechanisms by which DNA methylation modulates stress in algae are yet largely unresolved, mainly with respect to heavy metal stress, for which in plants, metal- and species- specific responses were instead evidenced. In this work, we performed a comparative Whole-Genome Bisulfite Sequencing (WGBS) on two strains of the green alga Scenedesmus acutus with different Cr(VI) sensitivity. The pattern of distribution of 5-mC showed significant differences between the two strains concerning both differentially methylated local contexts (CG, CHG and CHH) and Differentially Methylated Regions (DMRs) as well. We also demonstrated that DNA methylation plays an important role in modulating some genes for sulfate uptake/assimilation confirming the involvement of the sulfate pathway in the Cr-tolerance. Our results suggest that DNA methylation may be of particular importance in defining signal specificity associated with Cr-tolerance and in establishing new epigenetic marks which contribute to the adaptation to metal stress and also to transmit the epigenomic traits to the progeny.
DNA 甲基化是一种非常重要的表观遗传修饰，参与许多生物功能。尽管在各种植物物种中已经报道了许多关于 DNA 甲基化的研究，但对藻类中的全基因组 DNA 甲基化模式的研究却很少。更复杂的是，DNA 甲基化如何调节藻类中的应激反应的机制仍未得到充分解决，主要是关于重金属应激，而在植物中，已经有证据表明存在金属和物种特异性的反应。在这项工作中，我们对具有不同 Cr(VI)敏感性的两种绿藻 Scenedesmus acutus 菌株进行了全基因组亚硫酸氢盐测序（WGBS）比较。5-mC 的分布模式在两个菌株之间存在显著差异，涉及差异甲基化的局部上下文（CG、CHG 和 CHH）和差异甲基化区域（DMRs）。我们还证明，DNA 甲基化在调节硫酸盐摄取/同化的一些基因方面起着重要作用，这证实了硫酸盐途径在铬耐受中的参与。我们的结果表明，DNA 甲基化在定义与铬耐受相关的信号特异性以及建立新的表观遗传标记方面可能具有特别重要的意义，这些标记有助于适应金属应激，并将表观遗传特征传递给后代。
