Intergrated biochemical genomics and cellular platform for alkaloid biosynthetic gene discovery and characterization

长期以来，植物无与伦比的生物合成能力一直被开发，方法是在传统医学中使用许多物种，并使用纯代谢物作为药物、香料、香料、色素、杀虫剂和其他精细化学品。苄基异喹啉生物碱(BIAS)是一大类由酪氨酸衍生的植物专门化代谢物，通过分子内偶联、还原、甲基化、羟化和其他反应的复杂生化网络而多样化，产生&gt；2500个已知结构。几种偏爱(如镇痛剂吗啡、止咳药可待因、血管扩张剂罂粟碱和管库拉林)直接用作药物，或用作半合成药物(如羟考酮)的前体。植物仍然是这些化合物的唯一经济来源，因为它们的化学复杂性，这使得从头合成具有挑战性和成本。大多数关于BIA代谢的研究都是以生物合成酶和相应的基因为目标的，这些酶和相应的基因只在有限的物种中参与形成相对较少的化合物。植物专门化代谢的一个重要特征是酶通过随机突变获得新功能的能力。因此，一些相对有限的酶类型(即依赖于SAM的甲基转移酶、依赖于乙酰辅酶A的酰基转移酶、依赖于P450的单加氧酶、依赖于FAD的氧化还原酶、短链脱氢酶/还原酶和醛酮还原酶)主要是导致BIA结构多样性的不同骨架结构和功能基团替换的主要原因。基于对一系列栽培植物的代谢物和转录物图谱的整合和比较，功能基因组学策略将被用于鉴定和表征新的BIA生物合成酶。基因组学资源和分子遗传学工具将被用来识别和调节参与BIA代谢调节的转录因子。将确定新发现的BIA生物合成酶的细胞和亚细胞定位，并将研究可能的酶相互作用。

The unparalleled biosynthetic capacity of plants has long been exploited through the use of many species in traditional medicine and the application of pure metabolites as pharmaceuticals, flavours, fragrances, pigments, insecticides, and other fine chemicals. Benzylisoquinoline alkaloids (BIAs) are a large group of plant specialized metabolites derived from tyrosine and diversified by an intricate biochemical network of intramolecular coupling, reduction, methylation, hydroxylation, and other reactions that generate >2,500 known structures. Several BIAs (e.g. the analgesic morphine, the cough suppressant codeine, and the vasodilators papaverine and tubocurarine) serve directly as pharmaceuticals, or as precursors for semi-synthetic drugs (e.g. oxycodone). Plants remain the only economical source for these compounds due to their chemical complexity, which makes de novo synthesis challenging and costly. Most research on BIA metabolism has targeted biosynthetic enzymes and corresponding genes involved in the formation of relatively few compounds in only a limited number of species. An important feature of plant specialized metabolism is the ability of enzymes to acquire novel functions through random mutation. As such, a relatively limited number of enzyme types (i.e. SAM-dependent methyltransferases, acetylCoA-dependent acyltransferases, P450-dependent monooxygenases, FAD-dependent oxidoreductases, short-chain dehydrogenase/reductases and aldo-keto reductases) are largely responsible for the establishment of the diverse backbone structures and functional group substitutions responsible for BIA structural diversity. A functional genomics strategy based on the integration and comparison of metabolite and transcript profiles from a collection of cultured plant species will be used to identify and characterize novel BIA biosynthetic enzymes. Genomics resources and molecular genetic tools will be used to identify and modulate transcription factors involved in the regulation of BIA metabolism. The cellular and subcellular localization of newly discovered BIA biosynthetic enzymes will be determined, and possible enzyme interactions will also be investigated.