Melatonin in plant morphogenesis and development

褪黑素是最广为人知的松果体激素，它主要是发出黑暗的信号，但也调节着人类和其他脊椎动物的一些神经和生理功能。人们对植物褪黑素的兴趣正在迅速增长，因为它在预防神经疾病、癌症和许多与年龄相关的疾病方面具有潜在的健康益处。褪黑素在植物中的存在已有报道，但其在植物发育中的作用尚不清楚。该实验室的研究表明，褪黑素存在于一系列植物物种中，它的存在与自然和受控生长环境中的形态发生和植物发育有关。这些反应与内源褪黑激素及其前体5-羟色胺水平密切相关，包括高再生能力、花和种子形成以及植物对冷胁迫的适应。这些观察结果导致了一种假说，即植物的各种形态发生和发育过程是由激素或环境胁迫诱导的，并进一步由褪黑激素诱导的调节信号级联介导。拟议的研究计划侧重于阐明褪黑素在细胞、器官和整个植物水平上的作用机制的生理、生化和分子基础。具体的研究方面将包括分析在生长调节剂和高温或低温胁迫下的褪黑素及其代谢物，以及培育具有高抗氧化活性和内源褪黑素含量低和高的植物。该研究模型为理解褪黑激素在植物形态发生调控中的作用提供了一种新的途径，并具有开发耐高温植物模型的巨大潜力。此外，由于褪黑素对健康有多种好处，富含褪黑素的植物可能会为加拿大和国际市场提供新的天然保健产品。

Melatonin is best known as a pineal hormone which primarily signals darkness but also regulates a number of neurological and physiological functions in human and other vertebrates. Interest in plant melatonin is growing rapidly due to potential health benefits in the prevention of neurological disorders, cancer, and many age-related conditions. The occurrence of melatonin in plants has been reported recently, but its role in plant development is not yet understood. Research in this laboratory has shown that melatonin is present in a range of plant species and that its existence is associated with morphogenesis and plant development both in natural and controlled growth environments. The responses which were found closely linked with endogenous levels of melatonin and its precursor serotonin included high regenerative capacities, flower and seed formation, and adaptation of plants to cold stress. These observations led to the hypothesis that various morphogenetic and developmental processes in plants are induced by hormonal or environmental stresses and are further mediated by melatonin induced cascade of regulatory signals. The proposed research program is focused on elucidation of the physiological, biochemical, and molecular basis of the mechanisms of action of melatonin at the cellular, organ, and whole plant levels. Specific research aspects will include analysis of melatonin and its metabolites under stress imposed by growth regulators and high or low temperatures and development of plants with high antioxidant activity as well as low and high endogenous melatonin content. This research model represents a novel approach to understand the role of melatonin in the regulation of plant morphogenesis and has significant potential for developing a model to generate temperature-tolerant plants. Also, due to multiple health benefits of melatonin, melatonin-rich plants may provide novel natural health products for the Canadian and international market.