Designed to breathe: synthetic biology applications in plant hypoxia

Over the past years, plant hypoxia research has produced a considerable number of new resources to monitor low oxygen responses in model species, mainly Arabidopsis thaliana. Climate change urges the development of effective genetic strategies aimed at improving plant resilience during flooding events. This need pushes forward the search for optimized tools that can reveal the actual oxygen available to plant cells, in different organs or under various conditions, and elucidate the mechanisms underlying plant hypoxic responses, complementing the existing transcriptomics, proteomics, and metabolic analysis methods. Oxygen-responsive reporters, dyes, and nanoprobes are under continuous development, as well as novel synthetic strategies that make precision control of plant hypoxic responses realistic. In this review, we summarize the recent progress made in the definition of tools for oxygen response monitoring in plants, either adapted from bacterial and animal research or peculiar to plants. Moreover, we highlight how adoption of a synthetic biology perspective has enabled the design of novel genetic circuits for the control of oxygen-dependent responses in plants. Finally, we discuss the current limitations and challenges toward the implementation of synbio solutions in the plant low-oxygen biology field.