Flood severity and frequency are increasing strongly as a consequence of climate change. Floods have a devastating impact on crop productivity and understanding how a variety of plant species sense flooding and acclimate accordingly is essential for flood-resilient crop breeding. In our lab we study the spatiotemporal dynamics of flooding signals and how they mediate plant stress responses and development. Moreover, we are interested in how prior flooding events control plant development and stress responses during subsequent flooding stress, a process we call flooding memory.
Flooding signals control stress responses and development
Submerged plants use entrapment of the gaseous hormone ethylene as a potential flooding signal to acclimate to impending low-oxygen (hypoxia) stress. Ethylene signaling is integrated with the plant's oxygen sensing pathway and augments transcriptional hypoxia responses to promote survival chances. In addition, we find that ethylene improves antioxidant activity and may limit plant development temporarily until stressful conditions are over. How do plants use ethylene and hypoxia signals to find a tailored balance between increased stress responses on the one hand, and limit growth and development on the other? To what extent are the transcriptional changes controlled by changes in chromatin state and DNA methylation status, and do beneficial epigenetic changes last in time?
Flooding stress memory promotes tolerance to subsequent stress
Many organisms have the capacity for cellular or epigenetic memory of prior (stressful) events, including plants. This stress memory has been documented for a wide range of biotic and abiotic stresses and can help plants to acclimate faster during subsequent stressful events. We find that plants also have the capacity to remember flooding stress, which improves tolerance during additional flooding events. What signals do plants use to remember flooding stress? What are the memory-encoding mechanisms and targets to promote stress acclimation? Can we (epi)genetically introduce memories that never occured, or can we make flooded plants forget they were ever flooded? Do plants that typically live multiple years have a better capacity for stress memory compared to annual plants, and what can we learn from that? Understanding how plants regulate these process can give us insights for what is required for long-term stress tolerance in crops.