Recent advances in the mechanism, transduction and function of oxygen sensing in plants

Response to reduced ambient oxygen is a key component of plant adaptation in natural and farmed environments and is regulated by oxygen dependent proteolysis of transducer proteins through the PCO N-degron pathway. Following the discovery of the core biochemistry of sensing, components and downstream pathways associated with oxygen-sensing have been uncovered that link diverse stages and mechanisms of growth to the requirement for oxygen sensing. Recent developments in understanding the sensing and transduction of the low oxygen signal have highlighted the importance of hypoxia-regulated processes in root development and environmental response and have revealed a key role for cyclic hypoxia in leaf development. Although the pathway is highly conserved in eukaryotes, and important transducer proteins evolved early in land plants, multiple components are under active natural selection related to ambient oxygen levels associated with altitude or humidity. Here we provide an update focussed on recent advances in methodology and mechanistic understanding that highlight the importance of oxygen sensing in plant biology.