Flooding tolerance in plants

Global warming is associated with an increase in flooding events, making many ecosystems worldwide vulnerable to submergence. Water submersion can severely affect crop production, since it drastically reduces oxygen availability necessary for plants' respiration, thus survival. Plants tolerant to flooding evolved morphological, physiological and biochemical adaptations to oxygen deficiency. Recently, considerable progress has been made in terms of understanding the molecular aspects governing these responses. However, the upstream stress-sensing mechanism of oxygen shortage has not yet been fully understood and many of the systems described in bacteria, fungi and animals have been excluded for plants. Many studies on oxygen deprivation stress have focused on rice (Oryza sativa), since it is one of the crops better adapted to a flooded environment. Beside being able to germinate under submergence, rice varieties display different mechanisms for a successful survival. Agronomically, the study of rice strategies to survive flooding in ecotypes adapted to extreme environments shows big potential in the context of climate change and the worldwide increasing need for food.