Different survival strategies amongst plants to cope with underwater conditions

Many plants experience flooding at some point during their life cycle. The underwater environment creates a carbon and energy crisis for the plant, for which two successful strategies have been identified, quiescence and escape. During quiescence, growth is actively reduced until the water levels recede, whereas escape encompasses rapid upward shoot elongation to establish air contact. An inherent cost is associated with flood-induced elongation, which is also reflected by the difference in managing energy production and expenditure compared to plants adopting a quiescence strategy.

The underwater elongation, via a combination of cell elongation and division, is mainly driven by changes in the internal gaseous composition of ethylene, carbon dioxide, and oxygen. Interestingly, the same internal and environmental cues induce contrasting growth responses, depending on the species. The underlying hormonal network and molecular components constituting these differences amongst wetland species are further discussed.