Subventions et des contributions :

Subvention ou bourse octroyée s'appliquant à plus d'un exercice financier. (2017-2018 à 2022-2023)

Plants face a multitude of biotic and abiotic stresses due to their sessile nature and have evolved various strategies through which they can effectively balance growth and defense against stressors. A strategy employed by plants is to maintain an appropriate hormone balance at any given moment. Plant hormones are small molecules whose signaling pathways interact, together forming a complex crosstalk network that regulates the plant’s response to environmental stressors. The hormone abscisic acid (ABA) is critical for initiating a stress response within the plant, inhibiting growth and promoting survival under various stresses. Regardless of the type of stress that plants are exposed to, the result is energy deprivation that activates energy sensors to maintain energy homeostasis. SnRK1 (Sucrose non-fermenting Related Kinase1) is the plant ortholog of yeast Snf1 and mammalian AMPK energy sensors. Notably, AMPK is a metabolic tumour suppressor, currently a target for cancer and diabetes treatment and prevention. SnRK1 activation induces large transcriptional reprogramming under metabolic stress to conserve energy. Despite the pivotal role of these essential kinase complexes in energy homeostasis, few targets are known. SnRK1 and ABA signaling pathways intersect during stress responses to promote survival, however, the mechanism of this interaction is unclear.

Seeds constitute up to 70% of our food intake, as direct consumption and animal feed. The proposed research program aims to understand how hormones regulate plant responses to environmental cues, with a focus on seed development and early vegetative growth. A combination of molecular genetics and targeted systems biology approaches will be used to: a) study the mechanism of hormone crosstalk during seed development and germination under abiotic stresses; b) understand the mechanisms of interaction between the SnRK1 and ABA signaling pathways, both of which are activated during stress; c) identify novel regulators of seed development and germination under abiotic stresses. In the long term, we aim to understand how plants integrate endogenous signals and external cues to adapt to changing environments. Scarcity of fresh water and increasing temperature due to global climate change are major threats to food security. Plants ability to respond to environmental stressors is critical during reproductive development, at which time water and heat stresses, especially when combined, can severely reduce seed filling and cause great yield losses. This is a great concern in Canada, where increasing temperature and drought have negatively impacted the yield of important agricultural crops, such as wheat, canola and corn in the past years. The knowledge gained from this program will aid in the future selection of plants with enhanced stress tolerance during seed development, greatly improving the yield of important agricultural crops.