Serotonin in Morphogenesis: re-discovery of an ancient molecule

在过去的20年里，我的研究计划一直专注于了解褪黑素(MEL)在植物形态发生、发育和适应不断变化的环境中的作用。例如，我的研究团队进行的研究表明，MEL与营养生长和发育、衰老、有性繁殖以及抵御包括寒冷和光照在内的环境压力有关。在过去的50多年里，关于MEL在植物中的调控作用已经产生了大量的信息，但很少有研究专门研究其代谢前体5-羟色胺(Ser)在形态发生中的作用，或者它与植物对胁迫的反应的关系。鉴于最近对MEL缓解植物冷胁迫能力的观察，拟议的DG的总体目标将是更详细地研究Ser与MEL途径和其他植物生长调节剂在调节冷胁迫期间发生的生理事件的关系，因为关于这种化合物的信息很少。我们将结合化学分析、基因表达研究和显微镜结合量子点标记技术来研究Ser在冷胁迫中的可能作用。这种方法的独特之处在于，它不研究丝氨酸的单个作用步骤，而是将在细胞和整个植物水平上研究这种化合物的功能，从而更全面地了解这种独特的植物激素。这一点特别重要，因为Ser的作用位置和作用机制都是未知的，尽管目前关于MEL的信息有限。这项研究的一个新方面是假设Ser在植物对胁迫的反应中独立于MEL发挥作用。虽然大量的研究已经研究了MEL在植物中的作用，但其中许多工作并没有同时完整地研究Ser或色氨酸途径，这反过来又留下了许多关于这些分子的确切功能以及它们在植物响应胁迫过程中的关系的悬而未决的问题。这项提议旨在通过应用我的研究计划的最新进展，以及在受控环境中对植物生命进行实时成像、植物化学分析和操纵的新方法，来解开当前的谜团。这些结果对加拿大农业具有重要意义，因为这项工作可以为鉴定耐寒植物提供新的筛选参数，并通过靶向应用色氨酸代谢物，包括丝氨酸，引入潜在的作用来增强植物在田间的抗性。这项研究为各种应用奠定了基础，包括识别和引进耐逆作物或濒危物种，这不仅促进了保护和多样性，而且通过扩大可行的栖息地和种植区域来促进粮食安全。

Over the last 20 years my research program has focused on understanding the role of melatonin (Mel) in plant morphogenesis, development, and adaptation in changing environments. For instance, studies conducted by my research team have implicated Mel in vegetative growth and development, senescence, sexual reproduction, and protection against environmental stresses including cold and light. While a wealth of information pertaining to the regulatory role of Mel in plants has been generated over the last 50 odd years, few works have specifically investigated the role of its metabolic precursor serotonin (Ser) during morphogenesis, or its relationship to plant responses to stress. Given recent observations towards Mel ability to mitigate cold stress in plants, the overall objective of the proposed DG will be to examine in greater detail Ser relationship to the Mel pathway and other plant growth regulators in mediating physiological events incurred during cold stress, as there is little information available for this compound.A combination of chemical analysis, gene expression studies and microscopy coupled with quantum dot labeling technologies will be employed to investigate the putative role of Ser during cold stress. This approach is unique in that it does not investigate a single step in the action of Ser, but instead will examine the function of this compound at both the cellular and whole plant level allowing for a more comprehensive understanding of this unique phytohormone. This is particularly relevant as both location and mechanism of action are unknown for Ser, though limited information is currently available for Mel.A novel aspect of this research is the hypothesis that Ser acts independently of Mel during plant responses to stress. While a plethora of studies have investigated the role of Mel in plants, many of these works do not simultaneously examine Ser or the tryptophan pathway in full, which in turn has left many unanswered questions regarding the exact function of these molecules as well their relationship during plant responses to stress. This proposal aims to untangle the current mystery by applying recent advances from my research program, coupled with new approaches of live-imaging, phytochemical profiling and manipulation of plant life in controlled environments. These results have important implications for Canadian agriculture as this work can provide novel screening parameters for identification of cold tolerant plants as well as introducing a potential role for enhancing plant resistance in the field through target application of tryptophan metabolites, including Ser. This research lays the groundwork for diverse applications including identification and introduction of stress tolerant crops or at-risk species, which promotes not only conservation and diversity, but also food security through expansion of viable habitats and growing regions.