Nicotinamide‐adenine dinucleotide (NAD) is involved in redox homeostasis and acts as a substrate for NADases, including poly(ADP‐ribose) polymerases (PARPs) that add poly(ADP‐ribose) polymers to proteins and DNA, and sirtuins that deacetylate proteins. Nicotinamide, a by‐product of NADases increases circadian period in both plants and animals. In mammals, the effect of nicotinamide on circadian period might be mediated by the PARPs and sirtuins because they directly bind to core circadian oscillator genes. We have investigated whether PARPs and sirtuins contribute to the regulation of the circadian oscillator in Arabidopsis. We found no evidence that PARPs and sirtuins regulate the circadian oscillator of Arabidopsis or are involved in the response to nicotinamide. RNA‐seq analysis indicated that PARPs regulate the expression of only a few genes, including FLOWERING LOCUS C. However, we found profound effects of reduced sirtuin 1 expression on gene expression during the day but not at night, and an embryo lethal phenotype in knockouts. Our results demonstrate that PARPs and sirtuins are not associated with NAD regulation of the circadian oscillator and that sirtuin 1 is associated with daytime regulation of gene expression.

中文翻译：

---

拟南芥sirtuins和聚（ADP-核糖）聚合酶在白天调节基因表达但不影响昼夜节律

烟酰胺-腺嘌呤二核苷酸 (NAD) 参与氧化还原稳态并充当 NADases 的底物，包括将聚 (ADP-核糖) 聚合物添加到蛋白质和 DNA 的聚 (ADP-核糖) 聚合酶 (PARPs) 和使蛋白质脱乙酰的 Sirtuins . 烟酰胺是 NADases 的副产品，可增加植物和动物的昼夜节律。在哺乳动物中，烟酰胺对昼夜节律的影响可能由 PARPs 和 Sirtuins 介导，因为它们直接与核心昼夜节律振荡器基因结合。我们研究了 PARP 和 Sirtuins 是否有助于调节拟南芥中的昼夜节律振荡器。我们没有发现 PARP 和 Sirtuins 调节拟南芥的昼夜节律振荡器或参与对烟酰胺的反应的证据。RNA-seq 分析表明 PARPs 仅调节少数基因的表达，开花LOCUSÇ。然而，我们发现降低Sirtuin 1表达对白天而非夜间的基因表达的深远影响，以及敲除中的胚胎致死表型。我们的结果表明 PARPs 和 Sirtuins 与昼夜节律振荡器的 NAD 调节无关，而 Sirtuin 1与基因表达的白天调节相关。