BayCEER Workshop 2015

How to survive? Understanding flooding tolerance mechanisms using a tolerant dicot model system

P 1.3 in Special SPECIES and species' specialties

Over the past decades, extreme weather events increased significantly, causing dramatic crop losses since most crops are sensitive to flooding. Excess water leads to oxygen deficiency, which compromises photosynthesis and aerobic respiration, resulting in an energy crisis. Two strategies have been developed by plants to cope with flooding. Plants with an escaping strategy show rapid stem or petiole elongation to reach the water surface and restore air contact, whereas the quiescence strategy is defined by the down-regulation of plant growth and metabolism to save energy until the floods recede. For monocots, rice is a well-established flooding-tolerant model plant, whereas for dicots no flooding-tolerant model plant is available yet.

Our research is focused on comparing tolerance mechanisms of flooding-tolerant Brassicaceae species (Rorippa, Nasturtium, Cardamine) to the flooding-sensitive species Arabidopsis thaliana. The first flooding treatments indicated for instance that all tested rosette-growing species are quiescent whereas the non-rosette growing species displays an escaping strategy. Regarding flooding survival, we could not only see differences between escaping and quiescent species, but also a variation within the quiescent species with some species being considerably more flooding tolerant.

The use of RNAseq will provide information to identify the underlying mechanisms responsible for these effects. Furthermore, the main goal of our project is to establish a dicot model system for understanding flooding tolerance mechanisms, which could help in improving flooding tolerance of sensitive crop plants.

Keywords: Brassicaceae, flooding tolerance, escape and quiescence strategies, survival, RNA-sequencing