Plants can transmit information to the next generation and modulate the phenotype of their offspring through epigenetic mechanisms. In this study, we demonstrate the activation of ‘intergenerational acquired resistance’ (IAR) in the progeny of rice (Oryza sativa) plants exogenously treated with dehydroascorbate (DHA). The offspring of lifelong DHA-treated plants (DHA-IAR) were significantly less susceptible to the root-knot nematode Meloidogyne graminicola and partially inherited the DHA-induced transcriptional response found in the parental plants. Phytohormone analyses on the DHA-IAR plants unveiled higher basal abscisic acid (ABA) levels and a primed induction of the jasmonic acid (JA) pathway. RNA-seq analysis on the embryonic tissues of immature seeds of DHA-treated plants revealed major shifts in the expression of genes associated with epigenetic pathways. We confirmed that DHA treatment leads to a significant but transient pattern of global DNA hypomethylation in the parental plants at 12 to 24 hours after treatment. The induction of resistance in the parental plants requires the DNA demethylase REPRESSOR OF SILENCING 1C (ROS1c) and ARGONAUTE 4 (AGO), suggesting a role for DNA demethylation and subsequent re-methylation in establishment of this phenotype. Confirming the transience of global hypomethylation upon DHA treatment, no significant change in global DNA methylation levels was observed in DHA-IAR versus naïve plants. Finally, DHA could not induce IAR in the Ros1c mutant line and in the ARGONAUTE 4 (ago4ab)-RNAi line. These data indicate that a controlled collaboration between transient DNA demethylation and remethylation underlies the induced resistance and IAR phenotypes upon DHA treatment.

中文翻译：

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ARGONAUTE4 和 DNA 去甲基化酶 ROS1c 介导脱水抗坏血酸诱导的水稻代际线虫抗性


植物可以将信息传递给下一代，并通过表观遗传机制调节其后代的表型。在这项研究中，我们证明了用脱氢抗坏血酸 （DHA） 外源处理的水稻 （Oryza sativa） 植物后代中“代际获得性抗性”（IAR） 的激活。终生 DHA 处理植物 （DHA-IAR） 的后代对根结线虫 Meloidogyne graminicola 的敏感性显著降低，并且部分继承了在亲本植物中发现的 DHA 诱导的转录反应。对 DHA-IAR 植物的植物激素分析揭示了较高的基础脱落酸 （ABA） 水平和茉莉酸 （JA） 通路的启动诱导。对 DHA 处理植物的未成熟种子胚胎组织的 RNA-seq 分析揭示了与表观遗传途径相关的基因表达的重大变化。我们证实，DHA 处理导致处理后 12 至 24 小时亲本植物中显着但短暂的全局 DNA 低甲基化模式。亲本植物的抗性诱导需要 DNA 去甲基化酶沉默抑制因子 1C （ROS1c） 和 ARGONAUTE 4 （AGO），表明 DNA 去甲基化和随后的再甲基化在建立该表型中的作用。证实了 DHA 处理后整体低甲基化的短暂性，与幼稚植物相比，DHA-IAR 中未观察到整体 DNA 甲基化水平的显着变化。最后，DHA 不能在 Ros1c 突变系和 ARGONAUTE 4 （ago4ab）-RNAi 系中诱导 IAR。这些数据表明，瞬时 DNA 去甲基化和再甲基化之间的受控合作是 DHA 处理后诱导的耐药性和 IAR 表型的基础。