The diversity and complexity of secondary metabolites in tea plants contribute substantially to the popularity of tea, by determining tea flavors and their numerous health benefits. The most significant characteristics of tea plants are that they concentrate the complex plant secondary metabolites into one leaf: flavonoids, alkaloids, theanine, volatiles, and saponins. Many fundamental questions regarding tea plant secondary metabolism remain unanswered. This includes how tea plants accumulate high levels of monomeric galloylated catechins, unlike the polymerized flavan-3-ols in most other plants, as well as how they are evolved to selectively synthesize theanine and caffeine, and how tea plants properly transport and store these cytotoxic products and then reuse them in defense. Tea plants coordinate many metabolic pathways that simultaneously take place in young tea leaves in response to both developmental and environmental cues. With the available genome sequences of tea plants and high-throughput metabolomic tools as great platforms, it is of particular interest to launch metabolic genomics studies using tea plants as a model system. Plant metabolic genomics are to investigate all aspects of plant secondary metabolism at the genetic, genome, and molecular levels. This includes plant domestication and adaptation, divergence and convergence of secondary metaboloic pathways. The biosynthesis, transport, storage, and transcriptional regulation mechanisms of all metabolites are of core interest in the plant as a whole. This review highlights relevant contexts of metabolic genomics, outstanding questions, and strategies for answering them, with aim to guide future research for genetic improvement of nutrition quality for healthier plant foods.

中文翻译：

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探索植物代谢基因组学：以茶树为模型，化学合成，生物合成过程中的代谢复杂性和特殊代谢物的运输。

茶叶植物中次生代谢产物的多样性和复杂性通过确定茶的口味及其众多的健康益处，极大地促进了茶的普及。茶树植物的最显着特征是将复杂的植物次生代谢产物集中在一片叶子中：类黄酮，生物碱，茶氨酸，挥发物和皂苷。有关茶树二次代谢的许多基本问题仍未得到解答。这包括茶植物如何积累高水平的单体没食子儿茶素儿茶素，这不同于大多数其他植物中聚合的flavan-3-ols，以及茶树如何进化以选择性地合成茶氨酸和咖啡因，茶树如何正确运输和储存这些细胞毒性物质。产品，然后将其重新用于防御。茶树协调了许多新陈代谢途径，这些新陈代谢过程同时发生在年轻茶叶中，以响应发育和环境因素。利用茶树的可用基因组序列和高通量代谢组学工具作为强大的平台，使用茶树作为模型系统开展代谢基因组学研究尤为重要。植物代谢基因组学将在遗传，基因组和分子水平上研究植物次生代谢的各个方面。这包括植物驯化和适应，次生代谢途径的分歧和趋同。所有代谢产物的生物合成，运输，储存和转录调控机制都是整个植物的核心利益。这篇评论重点介绍了代谢基因组学的相关背景，未解决的问题，