biomolecules Article Biochemical and Comparative Transcriptome Analyses Reveal Key Genes Involved in Major Metabolic Regulation Related to Colored Leaf Formation in Osmanthus fragrans ‘Yinbi Shuanghui’ during Development Xuan Chen 1,2, Xiulian Yang 1,3, Jun Xie 2, Wenjie Ding 1,3, Yuli Li 1,3, Yuanzheng Yue 1,3,* and Lianggui Wang 1,3,* 1 Key Laboratory of Landscape Architecture, Jiangsu Province, College of Landscape Architecture, Nanjing Forestry University, No. 159 Longpan Road, Nanjing 210037, China;
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[email protected] (L.W.); Tel.: +86-138-0900-7625 (L.W.) Received: 25 February 2020; Accepted: 1 April 2020; Published: 4 April 2020 Abstract: Osmanthus fragrans ‘Yinbi Shuanghui’ not only has a beautiful shape and fresh floral fragrance, but also rich leaf colors that change, making the tree useful for landscaping. In order to study the mechanisms of color formation in O. fragrans ‘Yinbi Shuanghui’ leaves, we analyzed the colored and green leaves at different developmental stages in terms of leaf pigment content, cell structure, and transcriptome data. We found that the chlorophyll content in the colored leaves was lower than that of green leaves throughout development. By analyzing the structure of chloroplasts, the colored leaves demonstrated more stromal lamellae and low numbers of granum thylakoid.