Analysis of plant flooding response

Flooding represents an environmental stress that has widespread effects on plants in natural ecosystems as well as causing major crop losses. As climate change leads to more severe weather extremes, severe flooding events are likely to become even more frequent. Thus, there is intense interest in understanding how flooding affects plants and in identifying cellular and molecular targets for engineering flood resilience into crop species. Such research requires well controlled, highly reproducible flooding protocols for use in the laboratory. However, there are many ways that a plant can be flooded. For example, waterlogging of the soil, where water levels reach the soil surface, generally generates a hypoxic environment around the root system. In contrast, full submergence of the plant adds effects on the aerial organs such as impaired photosynthesis from the combination of lowered CO2 availability and the reduced light penetration into often turbid flood waters. In this chapter, approaches to imposing controlled flooding conditions to the model plant Arabidopsis thaliana are discussed. A series of straight-forward assays are then described to document the effects of stress-related changes in growth patterns, pigment accumulation and levels of oxidative stress. These assays are complemented by monitoring the expression of a series of molecular markers of flood response by qPCR.