Oxygen sensing and plant adaptation to flooding in a changing climate

In times of climate change, frequency and intensity of extreme weather events are rising and thus demand a higher resilience of crop plants to environmental influences, such as flooding events, to minimize yield losses. Flooding causes acute oxygen deprivation in plants, accompanied by an energy crisis, starvation, growth retardation and ultimately increased harvest losses. At a molecular level, fluctuating oxygen concentrations are sensed via plant cysteine oxidases (PCOs) that, as part of the N-degron pathway, oxygen-dependently oxidize substrates such as vernalization 2, little zipper 2 and, most prominently, transcription factors of the group VII ETHYLENE RESPONSE FACTORS (ERFVIIs) to render them for degradation. When stabilized under hypoxia owing to the lack of oxygen, ERFVIIs act as transcriptional activators of hypoxia-response genes to evoke appropriate acclimation. Crop engineering for improved submergence resilience is an important goal for future food security, and prolonging ERFVII stability is a promising strategy. Here we discuss the potential molecular consequences of this strategy in terms of stabilization of Cys-initiating proteins in commercially relevant crop species, as well as ways in which this may be achieved, including via PCO engineering. This article is part of the theme issue ‘Crops under stress: can we mitigate the impacts of climate change on agriculture and launch the ‘Resilience Revolution’?’.