Grant: Discovery Grants Program - Individual

Climate change threatens an estimated 20 % of the world's plant diversity and will present new challenges in the cultivation, harvest and management of horticultural and wild crop species. Plant growth regulators (PGRs) are chemical signals which enable plants to perceive and respond to environment and developmental cues. The indoleamines melatonin and serotonin are a relatively new class of PGR which have a dual function in mediating plant developmental and stress responses. In recent years the complexity of indoleamine biosynthesis is being increasingly recognized with multiple branches of the pathway and reverse reactions being possible, along with numerous conjugates, isomers and metabolites. Like auxin, melatonin is derived from tryptophan and my previous research has identified interactions between auxin and melatonin, as well as tryptophan metabolism and melatonin. My research has shown that the pathway is dynamic and diverse conjugates, metabolites and storage forms may be important in determining biological responses My long-term program objective is to understand the role of novel classes of plant growth regulators, particularly the indoleamines, in plant resilience and response to changing climates, to identify phytohormone markers of environmental resilience, and to apply this to the development and management of sustainable berry horticulture systems and ecosystems. My overall hypothesis is that the indoleamines are mediators of plant perception and response to environmental change. We will integrate lab, controlled environment and field studies to better understand characterize the role of the indoleamine pathway in mediating plant environmental resilience. My first program objective will expand beyond the limited number of crop and medicinal plants in existing literature. We will use a systematic approach to understanding the basis and origins of the dual function of melatonin in plants through characterization of melatonin concentration, action and location in diverse plant lineages. My second objective will expand this work to understand functions of newly identified indoleamine & tryptophan-derived metabolites in plants, including kynurenine, using a pathway-based approach. The lessons learned in the lab and controlled environment studies will then be taken to the field to validate PGR responses in a real-world setting. The genus Vaccinium encompasses commercially, medicinally and culturally important berries including cranberry, blueberry and huckleberry. Despite being high-value crops whose nutritional and health benefits have been rigorously researched, relatively little is known about environmental adaptations of berry species. Our results will contribute to identifying priority species for conservation, inform future agricultural and breeding programs, and enhace food security, leading to economic, health and environmental benefits to Canadians, while generating highly skilled and marketable HQP for the Canadian economy.