Golden Camellia refers to a group of species in the genus Camellia that display yellow petals. The secondary metabolites in these petals hold ornamental significance and potential health benefits. However, the biosynthetic mechanisms governing the synthesis of these metabolites in golden petals remain elusive, and the exploitation of their bioactive components is not fully realized. This research involved the collection and analysis of 23 species of golden Camellia, leading to the discovery that flavonols, particularly quercetin 3-O-glucoside and quercetin 7-O-glucoside, are the primary contributors to the golden flower pigmentation. Integrative transcriptomics and co-expression network analyses pinpointed CnFLS1 as a crucial gene in the biosynthetic pathway, which, in conjunction with CnCHS, CnF3'H, and CnUFGT, orchestrates the specific pathway for flower color development. The enzyme assays revealed a high affinity and catalytic efficiency of CnFLS1 for DHQ, and transient expression of CnFLS1 in tobacco was shown to enhance the biosynthesis of quercetin flavonols, highlighting the pathway specificity in golden Camellia. Moreover, strategic transformations of cultivated tomatoes with various biosynthetic genes yielded transgenic lines exhibiting yellow fruit and quercetin-enriched flesh. These modified lines not only contained distinct flavonol components characteristic of golden Camellia but also demonstrated markedly improved antioxidant capabilities and enhanced resistance. The outcomes of this study not only elucidate the metabolic processes underlying the pigmentation of golden Camellia flowers but also provide a foundation for the development of novel tomato breeds through synthetic biology.

中文翻译：

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阐明金山茶中黄酮醇生物合成的关键途径及其在番茄果实代谢基因改造中的应用


金山茶花是指山茶属的一组显示黄色花瓣的物种。这些花瓣中的次生代谢物具有观赏意义和潜在的健康益处。然而，控制这些代谢物在金色花瓣中合成的生物合成机制仍然难以捉摸，并且其生物活性成分的开发尚未完全实现。这项研究涉及对 23 种金山茶花的收集和分析，从而发现黄酮醇，特别是槲皮素 3-O-葡萄糖苷和槲皮素 7-O-葡萄糖苷，是金花色素沉着的主要贡献者。整合转录组学和共表达网络分析确定 CnFLS1 是生物合成途径中的关键基因，它与 CnCHS 、 CnF3'H 和 CnUFGT 一起协调花色发育的特异性途径。酶测定显示 CnFLS1 对 DHQ 具有高亲和力和催化效率，烟草中 CnFLS1 的瞬时表达显示可增强槲皮素黄酮醇的生物合成，突出了金山茶花的通路特异性。此外，对具有各种生物合成基因的栽培西红柿进行战略转化，产生了表现出黄色果实和富含槲皮素果肉的转基因品系。这些改性品系不仅含有金山茶花特有的独特黄酮醇成分，而且表现出显着提高的抗氧化能力和增强的抵抗力。本研究的结果不仅阐明了金黄色山茶花色素沉着的代谢过程，而且为通过合成生物学开发新型番茄品种提供了基础。