Regulation of source-sink development and leaf homeostasis in vascular plants that translocate monoterpenes as photo-assimilates in addition to sugars such as sucrose

维管植物是一种复杂的光合自养真核生物。它们是理想的生物反应器，因为它们提供了对我们的生存和福祉至关重要的有机化合物的可持续来源。植物已经进化出多种应对环境胁迫的生存机制。它们在空间和时间上的表型可塑性在生物学上是独特的，因为植物调节能量流，最初是由光合冠层捕获的太阳能转化为稳定和移动的形式的还原C、N和S。光合作用的主要来源是叶冠，但是，在营养和生殖周期与流行的信念相反，其他器官也有助于光合作用。如果我们要利用植物作为传统生物反应器（例如，食品、淀粉、糖、氨基酸、维生素等）和新的生物产品（例如，燃料、药物），我们必须提高对从源器官/组织到发育中的汇的同化物通量的理解。例如，通过维管韧皮部转运的还原C的形式取决于环境压力和冠层发育的状态。 源-库相互作用决定生产力，但代谢物通量仍然是最贫穷的理解植物过程之一。选择可以通过经典育种方案或使用分子生物技术来提高草本和木本作物生产力的基因需要量化运输通量。在圭尔夫的Biotron设施中，我们设计了新的分析工具，用于在生物体、器官和细胞器水平上量化表型可塑性。 在这个项目中，我们将测试新的育种系，新的生态型和转基因，每一个不同的遗传能力，以合成和运输大量的新还原的C作为单萜（葡萄糖酯，如环烯醚萜）以及更好地认识到糖二糖，蔗糖。特别令人感兴趣的是作为一个模式植物科是“新”重新分类的植物科，车前草科。这些将与豆科和豆科的选定成员进行比较，因为我们有机会测试叶片形状和库呼吸活性的靶向遗传修饰如何改变叶片中还原碳的流出。

Vascular plants are complex eukaryotes that are photoautotrophs. They are desirable bio-reactors because they offer a sustainable source of organic compounds essential to our survival and well being. Plants have evolved multiple survival mechanisms for dealing with environmental stress. Their spatial and temporal, phenotype plasticity is unique in biology as plants regulate energy flow, initially solar energy trapped by the photosynthetic canopy into stable and mobile forms of reduced C, N and S. A primary source of photoassimilates is the leaf canopy, but, during vegetative and reproductive cycles contrary to popular belief other organs also contribute photoassimilates. If we are to exploit plants as bio-reactors for traditional (e.g., food, starch, sugars, amino acids, vitamins, etc) and novel bio-products (e.g., fuel, pharmaceuticals) our understanding of assimilate fluxes from source organs/tissues to developing sinks must improve. For example, the forms of reduced-C that are translocated via vascular phloem vary depending on the environmental stress and status of canopy development. Source-sink interactions determine productivity yet metabolite fluxes remain one of poorest understood plant processes. Selecting genes that can be targeted by either classical breeding protocols or using molecular bio-technologies to improve productivity of herbaceous and woody crops requires quantification of transport fluxes. In the Biotron facilities at Guelph we have engineered new analytical tools that are required to quantify phenotype plasticity at the organism, organ and organelle levels. In this project we will test new breeding lines, novel ecotypes and transgenics each with different genetic abilities to synthesize and transport large amounts of newly reduced C as monoterpenes (glucose esters such iridoids) as well as the better recognized sugar disaccaride, sucrose. Of particular interest as a model botanical family is the "newly" reclassified botanic family, the Plantaginaceae. These will be compared to selected members of the Leguminosea and the Brassicaeae as we have an opportunity to also test how targeted genetic modification of leaf shape and sink respiratory activity has altered efflux of reduced-C from leaves.