Comparative methylomics and chromatin accessibility analysis in Osmanthus fragrans uncovers regulation of genic transcription and mechanisms of key floral scent production

作者：Yuanji Han, Miaomiao Lu, Shumin Yue, Ke Li, Meifang Dong, Luxian Liu, Hongyun Wang, Fude Shang · 发表于：Horticulture Research · 年份：2022 · DOI：10.1093/hr/uhac096 · 被引用次数：47 · 研究领域：Plant biochemistry and biosynthesis、Plant Gene Expression Analysis、Plant Molecular Biology Research

Abstract Linalool and ionone are two important aromatic components in sweet osmanthus petals, and the regulatory mechanisms that produce these two components remain unclear. In this study, we employed whole-genome methylation sequencing and ATAC-seq technology to analyze the genomic DNA methylation status and chromatin accessibility of the sweet osmanthus cultivars ‘Zaohuang’ and ‘Chenghong Dangui’. Results showed that the promoter region of TPS2, a key gene in the linalool synthesis pathway, was less methylated in ‘Chenghong Dangui’ than in ‘Zaohuang’. The chromatin was more accessible in ‘Chenghong Dangui’ than in ‘Zaohuang’, which resulted in a much stronger expression of this gene in ‘Chenghong Dangui’ than in ‘Zaohuang’. This eventually led to a high quantity of linalool and its oxides in the petals of ‘Chenghong Dangui’, but there were lower levels present in the petals of ‘Zaohuang’. These results suggest that DNA methylation and chromatin accessibility play major roles in linalool synthesis in sweet osmanthus. The methylation level of the promoter region of CCD4, a key gene for ionone synthesis, was higher in ‘Zaohuang’ than in ‘Chenghong Dangui’. The chromatin accessibility was lower in ‘Zaohuang’ than in ‘Chenghong Dangui’, although the expression of this gene was significantly higher in ‘Zaohuang’ than in ‘Chenghong Dangui’. ChIP-seq analysis and a series of experiments showed that the differential expression of CCD4 and CCD1 in the two cultivars may predominantly ...