The functional organization and control of plant carbohydrate and phosphate metabolism

新陈代谢是指在任何给定时间细胞内发生的所有酶催化的化学反应。了解细胞代谢的组织和控制非常重要，因为它在以下方面有关键的应用：i)阐明并最终解决人类健康中的许多问题和由‘代谢紊乱’引起的疾病；以及ii)重组DNA技术的有效生物技术应用，通过‘合理的代谢工程’创造‘改良的’动物、植物和微生物--其目标是改变代谢途径的输出。植物代谢工程在培育耐压力作物方面发挥着至关重要的作用，这些作物可为世界上迅速增长的人口增加可持续的粮食生产(同时节约淡水等宝贵资源)，并将大气中的二氧化碳循环利用为可再生的生物燃料和能源，以及一系列工业原料。我的研究项目旨在确定植物碳水化合物和磷(P)代谢的组织和控制。这是通过表征关键酶(蛋白质催化剂)的分子、调节和功能特性来实现的，这些酶控制：i)在种子发育过程中碳分配给重要的贮藏最终产品(淀粉、油和蛋白质)；ii)植物磷的获取和利用；磷是作物生长和发育所需的一种基本的但对环境有限制的常量营养素。我和我的HQP特别感兴趣的是识别和表征酶蛋白在活细胞合成后发生的共价修饰(即所谓的“翻译后修饰”或“PTM”)。这是因为PTMS可以调节酶的活性、亚细胞位置、与其他蛋白质的相互作用和/或对各种细胞外或细胞内信号的降解。有无可争辩的证据表明，可逆蛋白PTMS作为一种整合植物细胞信号、发育、代谢和逆境反应的主要机制具有重要意义。我们的研究在加拿大和世界各地的农业和环境保护问题上有着重要的应用，包括：i)有针对性地修改主要油料作物(如油菜和大豆)的储油和蛋白质水平，以及ii)开发磷高效作物，这是减少人类对不可再生、不可持续、污染和昂贵的磷肥的猖獗但高度低效使用所迫切需要的。在这一授权期间，我的HQP将继续将创新的蛋白质组、基因组和细胞生物学工具整合到他们的研究中。这些进展需要不断的重组、培训和优化，但在我们可以检验的假说类型上提供了量化的改进，并为现代植物科学中的HQP培训和职业生涯奠定了坚实的基础。

Metabolism refers to all of the enzyme-catalyzed chemical reactions occurring in a cell at any given time. Understanding the organization and control of cellular metabolism is of great importance as it has crucial applications to: i) elucidating and ultimately solving many problems in human health and disease arising from ‘metabolic disorders', & ii) the effective biotechnological application of recombinant DNA technology for creating ‘improved' animals, plants, and microbes via ‘rational metabolic engineering' -whose goal is to modify the output of metabolic pathways. Plant metabolic engineering is playing a crucial role in the creation of stress-tolerant crops for increasing sustainable food production for the world's rapidly expanding population (while conserving precious resources such as fresh water), as well as recycling atmospheric carbon dioxide into renewable biofuels and energy sources, and a host of industrial feed-stocks. My research program seeks to identify the organization and control of plant carbohydrate and phosphorus (P) metabolism. This is approached by characterizing the molecular, regulatory, and functional properties of key enzymes (protein catalysts) that control: i) carbon partitioning to important storage end-products (starch, oil, & protein) in developing seeds, & ii) plant P acquisition and use; P is an essential but environmentally limiting macronutrient needed for crop growth and development. My HQP and I are particularly interested in identifying and characterizing covalent modifications (i.e. so-called ‘post-translational modifications' or ‘PTMs') that occur to enzyme proteins after they have been synthesized by living cells. This is because PTMs can function to regulate an enzyme's activity, subcellular location, interactions with other proteins, &/or degradation in response to various extra- or intracellular signals. There is indisputable evidence for the critical importance of reversible protein PTMs as a major mechanism that integrates signaling, development, metabolism, and stress responses in plant cells. Our studies have significant applications to problems in Canadian and worldwide agriculture and environmental protection including the: i) targeted modification of storage oil versus protein levels in major oilseed crops such as canola and soybeans, and ii) development of P-use efficient crops, urgently needed to reduce mankind's rampant but highly inefficient use of non-renewable, unsustainable, polluting, and expensive phosphate fertilizers. During this granting period my HQP will continue to integrate innovative proteomic, genomic, and cell biology tools into their research. These advances require constant retooling, training, and optimization, but provide quantitative improvements in the types of hypotheses that we can test, and a solid foundation for HQP training and careers in modern plant sciences.