Yuan Xi, Ma Kaifeng, Zhang Man, Wang Jia, Zhang Qixiang
Beijing Key Laboratory of Ornamental Plants Germplasm Innovation and Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, Engineering Research Center of Landscape Environment of Ministry of Education, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education, School of Landscape Architecture, Beijing Forestry University, Beijing, China.
Front Genet. 2021 Dec 15;12:779557. doi: 10.3389/fgene.2021.779557. eCollection 2021.
DNA methylation is a common epigenetic modification involved in regulating many biological processes. However, the epigenetic mechanisms involved in the formation of floral scent have rarely been reported within a famous traditional ornamental plant emitting pleasant fragrance in China. By combining whole-genome bisulfite sequencing and RNA-seq, we determined the global change in DNA methylation and expression levels of genes involved in the biosynthesis of floral scent in four different flowering stages of . During flowering, the methylation status in the "CHH" sequence context (with H representing A, T, or C) in the promoter regions of genes showed the most significant change. Enrichment analysis showed that the differentially methylated genes (DMGs) were widely involved in eight pathways known to be related to floral scent biosynthesis. As the key biosynthesis pathway of the dominant volatile fragrance of , the phenylpropane biosynthesis pathway contained the most differentially expressed genes (DEGs) and DMGs. We detected 97 DMGs participated in the most biosynthetic steps of the phenylpropane biosynthesis pathway. Furthermore, among the previously identified genes encoding key enzymes in the biosynthesis of the floral scent of , 47 candidate genes showed an expression pattern matching the release of floral fragrances and 22 of them were differentially methylated during flowering. Some of these DMGs may or have already been proven to play an important role in biosynthesis of the key floral scent components of , such as /, /, , , //, and //////. In conclusion, our results for the first time revealed that DNA methylation is widely involved in the biosynthesis of floral scent and may play critical roles in regulating the floral scent biosynthesis of . This study provided insights into floral scent metabolism for molecular breeding.
DNA甲基化是一种常见的表观遗传修饰，参与调控许多生物学过程。然而，在中国一种著名的散发宜人香气的传统观赏植物中，参与花香形成的表观遗传机制鲜有报道。通过结合全基因组亚硫酸氢盐测序和RNA测序，我们确定了[植物名称]四个不同开花阶段花香生物合成相关基因的DNA甲基化和表达水平的全局变化。在开花期间，基因启动子区域“CHH”序列背景（H代表A、T或C）中的甲基化状态变化最为显著。富集分析表明，差异甲基化基因（DMG）广泛参与了八个已知与花香生物合成相关的途径。作为[植物名称]主要挥发性香气的关键生物合成途径，苯丙烷生物合成途径包含的差异表达基因（DEG）和DMG最多。我们检测到97个DMG参与了苯丙烷生物合成途径的大部分生物合成步骤。此外，在先前鉴定的[植物名称]花香生物合成关键酶编码基因中，47个候选基因的表达模式与花香释放相匹配，其中22个在开花期间发生了差异甲基化。这些DMG中的一些可能或已经被证明在[植物名称]关键花香成分的生物合成中发挥重要作用，如[具体成分名称1]/[具体成分名称2]、[具体成分名称3]/[具体成分名称4]、[具体成分名称5]、[具体成分名称6]、[具体成分名称7]/[具体成分名称8]和[具体成分名称9]。总之，我们的结果首次揭示DNA甲基化广泛参与花香生物合成，并可能在调控[植物名称]花香生物合成中发挥关键作用。本研究为分子育种的花香代谢提供了见解。
