Investigating the interface between plant metabolism and development

我的研究项目使用分子遗传学和生化工具来研究腺嘌呤和腺苷代谢相关的酶活性，以确定它们对植物发育的贡献。这些酶被认为是“家务”活动，因为它们在满足基本代谢需求的所有细胞中都有不同程度的表达；它们通常有助于多种生化途径。相应基因的突变会导致复杂的表型，当基因被敲除时，这些表型往往会导致不育或致命，这使得分析它们成为一个挑战。我们通过研究具有不同残留酶活性的突变体来剖析这些表型。这使我们能够确定每种酶活性影响的植物新陈代谢的临界点，以及依赖于该功能的植物发育的组成部分。我们的研究表明，这些酶发挥着令人惊讶的动态作用，影响着发育的关键方面，并影响着各种亚细胞隔室：一个是调节整个植物细胞中转甲基化反应所必需的关键蛋白质-蛋白质相互作用的“中枢”，另一个控制着蛋氨酸循环中产生的关键代谢物的丰度。这种代谢物含量的变化对植物的肥力和发育有至关重要的影响。对特定酶活性定向降低的突变体和基因沉默系的研究揭示了这些基本生化途径和植物激素信号之间的有趣串扰，其结果是关键发育事件的基础。我使用拟南芥进行这项研究，因为它很容易维护、遗传操作和分析。由于本研究的研究对象在所有植物中都存在，因此结果具有广泛的相关性。目前的研究有可能提高非生物胁迫耐受性，维管束发育，从而提高作物生产力。

My research program uses molecular genetic and biochemical tools to study enzyme activities associated with adenine and adenosine metabolism in order to identify their contributions to plant development. These enzymes are considered "housekeeping" activities as they are expressed in all cells to varying extents where they fulfill basic metabolic needs; they often contribute to multiple biochemical pathways. Mutations in the corresponding genes result in complex phenotypes that often involve sterility, or lethal, when knocked-out making them a challenge to analyze. We dissect these phenotypes by studying mutants that have differing residual enzyme activities. This allows us to determine the critical points in plant metabolism that each enzyme activity affects and the components of plant development that rely that function. Our research shows that these enzymes fulfill surprisingly dynamic roles impacting key aspects of development and affecting various subcellular compartments: one is a "hub" mediating critical protein-protein interactions essential for transmethylation reactions throughout plant cells, and another controls the abundance of a key metabolite produced in methionine recycling. Changes in the content of this metabolite have critical effects on plant fertility and development. The study of mutants and gene silencing lines with targeted reductions in specific enzyme activities reveals a fascinating crosstalk between these basic biochemical pathways and plant hormone signaling, the results of which underlie key developmental events. I use Arabidopsis thaliana for this research because it is easy to maintain, genetically manipulate and analyze. Because the targets of this research are present in all plants, the results have broad relevance. The current research has the potential to improve abiotic stress tolerance, vascular development and thus crop productivity.