Aerobic organisms developed systems to measure cellular oxygen levels and activate adaptive responses in case of hypoxia. This condition can be caused by the environment or associated with developmental programmes. Recent reports have revealed that complex eukaryotes, such as higher plants and metazoans, converged in their oxygen sensing strategies towards the recruitment of dioxygenase enzymes to regulate the activity of specific transcription factors. Despite the functional comparability of the mechanisms, their molecular components are different. These similarities and differences between animal and plant hypoxia machineries can now be exploited to acquire better understanding of the dynamics of oxygen sensing in the two kingdoms and more precise manipulation of these mechanisms for applicative purposes. For example this can be used to improve crops' ability to cope with hypoxic conditions induced by the surrounding environment, as it happens during flooding. Moreover, this can be used to re-engineer the metabolic and structural organisation that plant cells establish in response to oxygen gradients and fluctuations.
With SynOxyS, we apply a novel approach that merges the synthetic biology framework, molecular physiology, and developmental biology to transfer features of the metazoan oxygen sensing and delivery systems to plants. This strategy is instrumental to investigate for the first time whole oxygen machineries and characterize their performance in the context of plant cells.
The proposed project expands in three distinct although interlinked directions that explore (1) the exploitation of 2-oxoglutarate (OG)-dependent dioxygenase to drive selective proteolysis in plants, (2) the investigation of endogenous or heterologous control of chromatin accessibility by 2-OG dependent dioxygenases and (3) the engineering of a chimeric delivery system to alter oxygen provision or perception specifically in shoot apical meristems. The design and optimization of these synthetic oxygen machineries, and their comparison with endogenous ones, will pinpoint the features that enable efficient control of hypoxic responses in plants and will foster precise control of adaptive responses that ameliorate hypoxia tolerance.
