Serotonin in Morphogenesis: re-discovery of an ancient molecule

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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.