Overcoming short-day-dependent tuberization to adapt to long-day conditions is critical for the widespread geographical success of potato. The genetic pathways of photoperiodic tuberization are similar to those of photoperiodic flowering. DNA methylation plays an important role in photoperiodic flowering. However, little is known about how DNA methylation affects photoperiodic tuberization in potato. Here, we verified the effect of a DNA methylation inhibitor on photoperiodic tuberization and compared the DNA methylation levels and differentially methylated genes (DMGs) in the photoperiodic tuberization process between photoperiod-sensitive and photoperiod-insensitive genotypes, aiming to dissect the role of DNA methylation in the photoperiodic tuberization of potato. We found that a DNA methylation inhibitor could promote tuber initiation in strict short-day genotypes. Whole-genome DNA methylation sequencing showed that the photoperiod-sensitive and photoperiod-insensitive genotypes had distinct DNA methylation modes in which few differentially methylated genes were shared. Transcriptome analysis confirmed that the DNA methylation inhibitor regulated the expression of the key genes involved in the photoperiod and GA pathways to promote tuber initiation in the photoperiod-sensitive genotype. Comparison of the DNA methylation levels and transcriptome levels identified 52 candidate genes regulated by DNA methylation that were predicted to be involved in photoperiodic tuberization. Our findings provide a new perspective for understanding the relationship between photoperiod-dependent and GA-regulated tuberization. Uncovering the epigenomic signatures of these pathways will greatly enhance potato breeding for adaptation to a wide range of environments.

中文翻译：

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DNA甲基化通过介导与光周期和GA途径相关的基因表达影响马铃薯（Solanum tuberosum L.）的光周期块茎化

克服短日依赖的块茎化以适应长日条件对于马铃薯在地理上的广泛成功至关重要。光周期块茎化的遗传途径与光周期开花的遗传途径相似。DNA甲基化在光周期开花中起重要作用。然而，人们对 DNA 甲基化如何影响马铃薯的光周期结节化知之甚少。在这里，我们验证了 DNA 甲基化抑制剂对光周期结节的影响，并比较了光周期敏感和光周期不敏感基因型在光周期结节过程中的 DNA 甲基化水平和差异甲基化基因 (DMG)，旨在剖析 DNA 甲基化的作用。在马铃薯的光周期块茎化中。我们发现 DNA 甲基化抑制剂可以促进严格短日照基因型的块茎起始。全基因组 DNA 甲基化测序表明，光周期敏感和光周期不敏感基因型具有不同的 DNA 甲基化模式，其中很少有差异甲基化基因共享。转录组分析证实，DNA甲基化抑制剂调节参与光周期和GA途径的关键基因的表达，以促进光周期敏感基因型的块茎起始。DNA 甲基化水平和转录组水平的比较确定了 52 个受 DNA 甲基化调控的候选基因，这些基因被预测与光周期结节化有关。我们的研究结果为理解光周期依赖性和 GA 调节的块茎化之间的关系提供了新的视角。