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

维管植物是光合自养的复杂真核生物。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。植物进化出多种生存机制来应对环境胁迫。它们的时空、表型可塑性在生物学中是独特的，因为植物调节能量流，最初被光合冠层捕获的太阳能转化为稳定的、可移动的还原型C、N和s。光同化物质的主要来源是叶冠层，但是，在营养和生殖周期中，与普遍看法相反，其他器官也提供光同化物质。如果我们要利用植物作为传统（如食物、淀粉、糖、氨基酸、维生素等）和新型生物产品（如燃料、药品）的生物反应器，我们必须提高对从源器官/组织到发展汇的同化通量的理解。例如，通过维管韧皮部转运的还原- c的形式取决于环境胁迫和冠层发育状况。源库相互作用决定生产力，但代谢物通量仍然是最不了解的植物过程之一。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目标基因需要对运输通量进行量化。在圭尔夫的Biotron设施中，我们设计了新的分析工具，需要在生物体，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品系、新的生态型和转基因品种，它们具有不同的遗传能力，可以合成和运输大量新还原的C作为单萜烯（葡萄糖酯，如环烯醚）以及更好识别的糖苷，蔗糖。作为一个模式植物科，特别有趣的是“新”重新分类的植物科，车前花科。这些将与豆科和芸苔科的选定成员进行比较，因为我们也有机会测试叶片形状和呼吸活动的靶向基因修饰如何改变叶片中减少的c的外排。

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.