PDF(Pubmed)
Abstract：
The azalea (Rhododendron simsii Planch.) is an important ornamental woody plant with various medicinal properties due to its phytochemical compositions and components. However little information on the metabolite variation during flower development in Rhododendron has been provided. In our study, a comparative analysis of the flavonoid profile was performed in Rhododendron pulchrum sweet at three stages of flower development, bud (stage 1), partially open flower (stage 2), and full bloom (stage 3). A total of 199 flavonoids, including flavone, flavonol, flavone C-glycosides, flavanone, anthocyanin, and isoflavone were identified. In hierarchical clustering analysis (HCA) and principal component analysis (PCA), the accumulation of flavonoids displayed a clear development stage variation. During flower development, 78 differential accumulated metabolites (DAMs) were identified, and most were enriched to higher levels at the full bloom stage. A total of 11 DAMs including flavone (chrysin, chrysoeriol O-glucuronic acid, and chrysoeriol O-hexosyl-O-pentoside), isoflavone (biochanin A), and flavonol (3,7-di-O-methyl quercetin and isorhamnetin) were significantly altered at three stages. In particular, 3,7-di-O-methyl quercetin was the top increased metabolite during flower development. Furthermore, integrative analyses of metabolomic and transcriptomic were conducted, revealing that the contents of isoflavone, biochanin A, glycitin, and prunetin were correlated with the expression of 2-hydroxyisoflavanone dehydratase (HIDH), which provide insight into the regulatory mechanism that controls isoflavone biosynthesis in R. pulchrum. This study will provide a new reference for increasing desired metabolites effectively by more accurate or appropriate genetic engineering strategies.
摘要：
杜鹃花（杜鹃花。）是一种重要的观赏木本植物，由于其植物化学成分和成分而具有多种药用特性。然而，关于杜鹃花发育过程中代谢物变化的信息很少。在我们的研究中,在花发育的三个阶段，对杜鹃花甜味中的类黄酮进行了比较分析，芽（阶段1），部分开放的花（阶段2），盛开（第3阶段）。总黄酮199种，包括黄酮,黄酮醇，黄酮C-糖苷，黄烷酮,花青素,并鉴定了异黄酮。在层次聚类分析(HCA)和主成分分析(PCA)中，黄酮类化合物的积累表现出明显的发育阶段变异。在花卉发育过程中,鉴定了78种差异积累代谢物(DAMs)，大多数在盛开阶段被丰富到更高的水平。共有11个DAM，包括黄酮(chrysin，黄二醇O-葡萄糖醛酸，和黄二酚O-己糖-O-戊糖苷），异黄酮（BiochaninA），黄酮醇（3,7-二-O-甲基槲皮素和异鼠李素）在三个阶段发生显着变化。特别是,3,7-二-O-甲基槲皮素是花发育过程中最高增加的代谢产物。此外，进行了代谢组和转录组的综合分析，揭示了异黄酮的含量，biochaninA,缩水甘油,和prunetin与2-羟基异黄酮脱水酶（HIDH）的表达相关，这提供了对控制罗氏菌异黄酮生物合成的调节机制的见解。本研究将为通过更准确或更合适的基因工程策略有效增加所需代谢物提供新的参考。
