Abstract
Flooding is an increasingly common event that severely affects terrestrial plants including major crops. Submergence causes severe reductions in light levels and gas exchange with the environment, causing a significant carbon and energy crisis leading to death of the plant. However, death seems to be a highly coordinated process beginning with the old leaves and ending with the youngest. The shoot meristem endures the longest, and can regrow leaves once the flood recedes. The apparent fast senescence of old leaves could provide resources for young leaves and the meristem, enhancing their survival. It thus represents an effective strategy for plants to survive strenuous periods of submergence. So far, this mechanism remains unclear and the processes and signalling events unknown. Controlled death of a leaf includes a range of steps, each of which can be manipulated with genetic or pharmaceutical approaches, allowing us to assess if and how breakdown processes contribute to leaf death. We will investigate carbon transport throughout the plant with isotope labelling studies, and investigate which genes are responsible for the observed carbon distribution. The gained physiological understanding combined with tissue specific ‘omics profiling will identify candidate genes and regulatory mechanisms responsible for the differential rate of death of young and old leaves. These will be validated and functionally characterized with the abundance of tools available in the model plant Arabidopsis. In short, this proposal will investigate the mechanisms and consequences of whole plant integration of resources, which will have major implications for submergence tolerance.
Netherlands