Instituto de Biología Agrícola Mendoza-IBAM, Facultad de Ciencias Agrarias, Universidad Nacional de Cuyo, A. Brown 500, M5528AHB, Chacras de Coria, Mendoza, Argentina.
Plant Cell Rep. 2012 Aug;31(8):1449-61. doi: 10.1007/s00299-012-1260-x. Epub 2012 Apr 8.
Phenotypic plasticity is often postulated as a principal characteristic of tuber-bearing wild Solanum species. The hypotheses to explore this observation have been developed based on the presence of genetic variation. In this context, evolutionary changes and adaptation are impossible without genetic variation. However, epigenetic effects, which include DNA methylation and microRNAs expression control, could be another source of phenotypic variation in ecologically relevant traits. To achieve a detailed mechanistic understanding of these processes, it is necessary to separate epigenetic from DNA sequence-based effects and to evaluate their relative importance on phenotypic variability. We explored the potential relevance of epigenetic effects in individuals with the same genotype. For this purpose, a clone of the wild potato Solanum ruiz-lealii, a non-model species in which natural methylation variability has been demonstrated, was selected and its DNA methylation was manipulated applying 5-Azacytidine (AzaC), a demethylating agent. The AzaC treatment induced early flowering and changes in leaf morphology. Using quantitative real-time PCR, we identified four miRNAs up-regulated in the AzaC-treated plants. One of them, miRNA172, could play a role on the early flowering phenotype. In this work, we showed that the treatment with AzaC could provide meaningful results allowing to study both the phenotypic plasticity in tuber-bearing Solanum species and the inter-relation between DNA methylation and miRNA accumulations in a wide range of species.
表型可塑性通常被认为是具有块茎的野生茄属物种的主要特征。探索这一观察结果的假设是基于遗传变异的存在。在这种情况下，如果没有遗传变异，进化变化和适应是不可能的。然而，表观遗传效应，包括 DNA 甲基化和 microRNA 表达调控，可以成为生态相关特征表型变异的另一个来源。为了详细了解这些过程的机制，有必要将表观遗传效应与基于 DNA 序列的效应分开，并评估它们对表型可变性的相对重要性。我们探讨了具有相同基因型的个体中表观遗传效应的潜在相关性。为此，选择了一个野生马铃薯 Solanum ruiz-lealii 的克隆，这是一个非模式物种，已经证明了其天然甲基化的变异性，并用 5-氮杂胞苷（AzaC）处理其 DNA 甲基化，这是一种去甲基化剂。AzaC 处理诱导了早期开花和叶片形态的变化。通过定量实时 PCR，我们鉴定了在 AzaC 处理的植物中上调的四个 microRNA。其中之一，miRNA172，可能在早期开花表型中发挥作用。在这项工作中，我们表明，AzaC 的处理可以提供有意义的结果，允许在广泛的物种中研究具有块茎的茄属物种的表型可塑性以及 DNA 甲基化和 microRNA 积累之间的相互关系。
