Camphor Engineering and Technology Research Center of National Forestry and Grassland Administration, Jiangxi Academe of Forestry, Nanchang 330032, China.
Jiangxi Provincial Key Laboratory of Improved Variety Breeding and Efficient Utilization of Native Tree Species (NO. 2024SSY04091), Jiangxi Academe of Forestry, Nanchang 330032, China.
Int J Mol Sci. 2024 Sep 19;25(18):10084. doi: 10.3390/ijms251810084.
Short-chain dehydrogenase/reductases (SDRs) are the largest NAD(H)-dependent oxidoreductase superfamilies and are involved in diverse metabolisms. This study presents a comprehensive genomic analysis of the superfamily in a species that is one of the most significant woody essential oil plants in southern China. We identify a total of 222 CcSDR proteins and classify them into five types based on their cofactor-binding and active sites: 'atypical', 'classic', 'divergent', 'extended', and 'unknown'. Phylogenetic analysis reveals three evolutionary branches within the CcSDR proteins, and further categorization using the SDR-initiative Hidden Markov model resulted in 46 families, with the CcSDR110C, CcSDR108E, and CcSDR460A families being the most populous. Collinearity analysis identified 34 pairs of Cc paralogs in , 141 pairs of orthologs between and , and 59 pairs between and . Expression profile analysis indicates a preference for the expression of 77 genes in specific organs such as flowers, bark, twigs, roots, leaves, or fruits. Moreover, 77 genes exhibit differential expression patterns during the four developmental stages of leaves, while 130 genes show variance across the five developmental stages of fruits. Additionally, to explore the biosynthetic mechanism of methyl eugenol, a key component of the leaf essential oil in the methyl eugenol chemotype, this study also identifies eugenol synthase (EGS) within the CcSDR460A family through an integrated strategy. Real-time quantitative PCR analysis demonstrates that the expression of in the leaves of the methyl eugenol chemotype is more than fourfold higher compared to other chemotypes. When heterologously expressed in , it catalyzes the conversion of coniferyl acetate into a mixture predominantly composed of eugenol (71.44%) and isoeugenol (21.35%). These insights pave the way for future research into the functional diversity of genes, with a focus on secondary metabolism.
短链脱氢/还原酶（SDRs）是最大的 NAD（H）依赖性氧化还原酶超家族，参与多种代谢。本研究对中国南方最重要的木本精油植物之一的 SDR 超家族进行了全面的基因组分析。我们总共鉴定了 222 个 CcSDR 蛋白，并根据它们的辅因子结合和活性位点将它们分为五类：“非典型”、“经典”、“分歧”、“扩展”和“未知”。系统发育分析显示 CcSDR 蛋白存在三个进化分支，进一步使用 SDR-initiative 隐马尔可夫模型进行分类，得到了 46 个家族，其中 CcSDR110C、CcSDR108E 和 CcSDR460A 家族最为丰富。共线性分析确定了 34 对 中的 Cc 旁系同源物，141 对 之间的 直系同源物，以及 59 对 之间的 直系同源物。表达谱分析表明，77 个基因在花、树皮、嫩枝、根、叶或果实等特定器官中的表达偏好。此外，77 个基因在叶片的四个发育阶段表现出不同的表达模式，而 130 个基因在果实的五个发育阶段表现出差异。此外，为了探索叶精油中关键成分丁香酚的生物合成机制，本研究还通过综合策略在 CcSDR460A 家族中鉴定了丁香酚合酶（EGS）。实时定量 PCR 分析表明，在丁香酚化学型叶片中， 基因的表达比其他化学型高出四倍以上。当在 中异源表达时，它催化 coniferyl 乙酸酯转化为主要由丁香酚（71.44%）和异丁香酚（21.35%）组成的混合物。这些结果为进一步研究 基因的功能多样性奠定了基础，重点是次生代谢。
