Metabolism and Functions of 4-Aminobutyrate (GABA) in Plants

植物中完整的基因和蛋白质序列正迅速变得可用，人们越来越需要了解蛋白质的结构/功能和代谢途径的调节。在过去的25年里，我的实验室在植物中氨基酸4-氨基丁酸酯（GABA）和短链脂肪酸4-羟基丁酸酯（GHB）的代谢和功能方面取得了国际公认的领先地位，与GABA非常相似。它们是哺乳动物神经系统的内源性成分，其中GABA在神经传递和发育中发挥作用，并通过与专门受体的相互作用发挥作用，GHB作为神经递质或神经调节剂，假定通过GABA受体或独立的GHB特异性受体起作用。GABA和GHB在植物中的生理作用尚不清楚，但有证据表明它们与胁迫、信号传导和发育有关。GABA代谢与多种生物化学过程相互作用，其调控涉及基因依赖性和非依赖性过程，这一点越来越清楚。阐明GABA通路的主要应激和发育特异性反应及其与C/N网络和各种信号通路的相互作用需要时间过程实验和同时监测野生型植物和基因突变体中的相关基因和代谢物。我们目前的研究重点是模式植物拟南芥（Arabidopsis thaliana），因为分子试剂的可用性，以及苹果（Malus x domestica）果实，因为它们在控制空气储存过程中容易受到生理伤害，这是一种非生物胁迫。我们也研究水稻（Oryza sativa）和番茄（Solanum lycopersicum）的比较目的和商业利益。我们的方法是创新和综合的，使用生理、生化和生物技术方法来识别和理解与这些代谢物相关的基因/蛋白质和途径的调控。我们的研究结果不仅推动了基础知识的发展，而且为重要作物的非生物和生物抗逆性和发育变化的工程/开发提供了潜在的策略。

Entire sets of gene and protein sequences in plants are rapidly becoming available, and there is increasing need to understand protein structure/function and regulation of metabolic pathways. For the past 2.5 decades, my laboratory has developed internationally recognized leadership in the metabolism and function(s) in plants, of the amino acid 4-aminobutyrate (GABA) and the short-chain fatty acid 4-hydroxybutyrate (GHB), which closely resembles GABA. They are endogenous constituents of the mammalian nervous system, wherein GABA plays a role in neural transmission and development, and functions through interactions with specialized receptors, and GHB serves as a neurotransmitter or neuromodulator postulated to act via a GABA receptor or an independent GHB-specific receptor. The physiological roles of GABA and GHB in plants are not yet clear, but evidence suggests that they are linked to stress, signaling and development. It is becoming clear that GABA metabolism interacts with various biochemical processes and that gene-dependent and -independent processes are involved in its regulation. Elucidation of primary stress- and development-specific responses of the GABA pathway and their interplay with the C/N network and various signaling pathways requires time course experiments and simultaneous monitoring of the relevant genes and metabolites in wild-type plants and genetic mutants. Our current research focuses on the model plant Arabidopsis thaliana because of the availability of molecular reagents, as well as apple (Malus x domestica) fruit because they are prone to physiological injury during controlled atmosphere storage, an abiotic stress. We also study rice (Oryza sativa) and tomato (Solanum lycopersicum) for comparative purposes and for commercial interest. Our approach is innovative and integrative, using physiological, biochemical, and biotechnological methods to identify and understand the regulation of genes/proteins and pathways associated with these metabolites. Our results not only advance fundamental knowledge, but also suggest potential strategies for engineering/developing abiotic and biotic stress resistance and developmental changes in important crop plants.