Previous work has demonstrated that plants can be used as production platforms for molecules used in health, medicine, and agriculture. Production has been exemplified in both stable transgenic plants and using transient expression strategies. In particular, species of Nicotiana have been engineered to produce a range of useful molecules, including insect sex pheromones, which are valued for species-specific control of agricultural pests. To date, most studies have relied on strong constitutive expression of all pathway genes. However, work in microbes has demonstrated that yields can be improved by controlling and balancing gene expression. Synthetic regulatory elements that provide control over the timing and levels of gene expression are therefore useful for maximizing yields from heterologous biosynthetic pathways. In this study, we demonstrate the use of pathway engineering and synthetic genetic elements for controlling the timing and levels of production of Lepidopteran sex pheromones in Nicotiana benthamiana. We demonstrate that copper can be used as a low-cost molecule for tightly regulated inducible expression. Further, we show how construct architecture influences relative gene expression and, consequently, product yields in multigene constructs. We compare a number of synthetic orthogonal regulatory elements and demonstrate maximal yields from constructs in which expression is mediated by dCas9-based synthetic transcriptional activators. The approaches demonstrated here provide new insights into the heterologous reconstruction of metabolic pathways in plants.

中文翻译：

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本塞姆氏烟草昆虫信息素生物合成的可调控制


先前的工作已经证明植物可以用作健康、医学和农业分子的生产平台。已在稳定转基因植物和使用瞬时表达策略中举例说明了生产。特别是，烟草物种经过改造可产生一系列有用的分子，包括昆虫性信息素，这些分子对于农业害虫的物种特异性控制具有重要意义。迄今为止，大多数研究都依赖于所有途径基因的强组成型表达。然而，微生物研究表明，可以通过控制和平衡基因表达来提高产量。因此，控制基因表达时间和水平的合成调控元件可用于最大化异源生物合成途径的产量。在这项研究中，我们展示了利用途径工程和合成遗传元件来控制本塞姆氏烟草中鳞翅目性信息素产生的时间和水平。我们证明铜可以用作严格调控的诱导表达的低成本分子。此外，我们展示了构建体结构如何影响相对基因表达，从而影响多基因构建体中的产物产量。我们比较了许多合成的正交调控元件，并证明了由基于 dCas9 的合成转录激活剂介导表达的构建体的最大产量。这里展示的方法为植物代谢途径的异源重建提供了新的见解。