Artificial Sweetener? A Functional Genomics Interrogation of the Impact of Soluble Carbohydrate Metabolism on Poplar Cell Wall Biosynthesis

长寿的生物，如树木，提供了一个独特的系统来研究植物如何分配碳，因为它们的多年生性质允许询问对环境线索变化的复杂反应，同时避免稀释一年生植物常见的遗传分离所产生的表型反应。树木，像所有的植物一样，在分配碳的能力上具有固有的可塑性，这是有效调节生长和发育的关键。最终，资源分配由基因表达控制，基因表达转化为各种可溶性代谢物的积累，包括碳水化合物和酚类化合物。由此产生的化学物质定义了生理学，重要的是，影响植物的形态，功能和健康。曼斯菲尔德研究计划的长期目标是了解杨树碳分配的复杂基本过程，特别强调控制可溶性碳水化合物代谢的生物合成过程的复杂性以及这些代谢产物如何促进细胞壁发育。这些信息对于理解程序化的细胞生长模式，以及从源组织到汇组织的碳转运的复杂网络和调控框架至关重要，其中木材发育是重要的终端产品。拟议的研究建立在曼斯菲尔德实验室以前的NSERC发现赠款的基础上，以测试与杨树中形成植物碳分配的分子相互作用的广度相关的假设。具体而言，拟议的研究计划包括一个旨在解决以下目标的实验主体：1）阐明在杨树的可转位的光合同化物的性质; 2）跟踪碳供应的杨树发展木质部的命运，和3）解剖之间的相互作用，蔗糖合成，果糖再循环，和碳水化合物信号在杨树库组织。 更好地了解支持树木资源分配的分子控制也可以促进旨在选择，育种和/或工程树木的战略，最大限度地提高资源分配和战略性地将碳导向植物生物量。

Long-lived organisms, such as trees, offer a unique system to investigate how plants allocate carbon, as their perennial nature permits an interrogation of the complex responses to variations in environmental cues while avoiding the dilution of phenotypic responses that arise from genetic segregation common to annual plants. Trees, like all plants, possess an inherent plasticity in their ability to allocate carbon, which is pivitol to the effective modulation of growth and development. Ultimately, resource allocation is controlled by gene expression, which translates into the accumulation of a variety of soluble metabolites, including carbohydrates and phenolics. The resulting chemistry defines the physiology and, importantly, impacts plant form, function and fitness. The long-term objectives of the Mansfield research program, is to understand the complex fundamental processes of carbon allocation in Populus, with a specific emphasis on the intricacies of the biosynthetic processes governing soluble carbohydrate metabolism and how these metabolites contribute to cell wall development. This information is pivotal to understanding programmed cellular growth patterns, and the complex network and regulatory frameworks fundamental to carbon translocation from source tissues to sink tissues, where wood development is a substantial terminal product. The proposed research builds on the previous NSERC Discovery Grants in the Mansfield lab as a foundation to test hypotheses related to the breadth of molecular interactions that shape plant carbon allocation in Populus. Specifically, the proposed research program comprises a body of experiments aimed to address the following objectives: 1) elucidate the nature of the translocatable photoassimilate in Populus; 2) track the fate of carbon supplying the developing xylem of Populus, and 3) dissect the interplay between sucrose synthesis, fructose recycling, and carbohydrate signaling in Populus sink tissue. A greater understanding of the molecular controls that underpin resource allocation in trees could also facilitate strategies aimed at selecting, breeding, and/or engineering trees that maximize resource allocation and strategically direct carbon to vegetative biomass.