Biology subjects

Telara, Y.

Publications and source records attributed to Telara, Y..

4 recordsLinked to original sources

bioRxiv2025

KDM7-mediated oxygen sensing reprograms chromatin to enhance hypoxia tolerance in the root

Roots frequently encounter low oxygen (hypoxia) from soil compaction or water saturation and must adapt to this stress. We investigated how root tip cells sense hypoxia and adjust the meristem epigenome to activate genes that promote tolerance and growth under oxygen limitation. In Arabidopsis root tips, hypoxia tolerance was linked to increased trimethylation of histone H3 at lysine 4 (H3K4me3). We also found that group 7 demethylases (KDM7s) are directly inhibited by hypoxia, and that genetic inactivation of KDM7s, like hypoxia, induces expression of genes essential for meristem survival under oxygen deprivation. We propose that KDM7s function as root-specific oxygen sensors that prime and support hypoxia tolerance.

plant biology↗

bioRxiv2025

Hydrogen sulfide modulates plant hypoxic responses through the persulfidation of Plant Cysteine Oxidases

Hydrogen sulfide (H2S) is a gaseous molecule historically regarded as toxic. Nevertheless, increasing evidence has brought to light important physiological roles in both animals and plants. In plants, H2S is involved in environmental and developmental responses, such as stomatal closure and seed germination, and in tolerance mechanisms to different stress conditions like salinity, drought and waterlogging. In this study, we report a function of H2S as a modulator of hypoxic responses in Arabidopsis thaliana. A combination of biochemical and genetic evidence demonstrates that H2S inhibits the activity of Plant Cysteine Oxidases, the molecular sensors of oxygen, through protein persulfidation to modulate hypoxia-associated responses. Furthermore, we show that H2S physiology contributes to responses to low oxygen, as disturbing H2S production impaired activation of hypoxia-responsive genes and submergence tolerance. Overall, this work introduces H2S as signalling modulator in plant hypoxic responses and adds a regulatory layer to the plant oxygen-sensing mechanism.

plant biology↗

bioRxiv2025

Severe Fe deficiency promotes hypoxia inducible responses in Arabidopsis thaliana

In plants, Fe homeostasis and O2 metabolism are strictly related, indeed several Fe-requiring enzymes catalyze reactions that also involve oxygen, as a reagent, product, entry or end point of the metabolic pathway in which the enzyme takes part. Oxygen sensing itself relies on Fe-dependent enzymes, the Plant cysteine oxidase (PCO) family of 2-OG independent thiol dioxygenases. PCOs are responsible for the degradation of ERFVII ethylene-responsive factors through a proteasomal N-degron pathway that connects hypoxia-inducible responses to the stabilization of the ERFVII transcription factors. Here, we investigated the interplay between low oxygen and Fe-deficiency stresses in A. thaliana. We used plants expressing a genetically encoded reporter of ERFVII protein stability and measured the expression of anaerobic genes to infer PCO activity in vivo. Our results highlight that Fe deprivation can elicit hypoxia-like responses depending on its severity. To test the involvement the ERFVII factors further, we examined the response of a pentuple erfVII mutant to Fe-deficiency stress, individually or combined with low oxygen. Our data indicate that the ERFVIIs might take part to the acclimation to chronic Fe deficiency by acting as positive regulators of starvation-responsive genes. Moreover, our results suggest that the ERFVIIs fine-tune nutrient mobilization to the shoots of submerged plants growing on moderately Fe-deficient substrates. This work expands the known functions of the ERFVII factors and provides new information to understand plant responses to combined environmental stresses.

plant biology↗

bioRxiv2024

H2O2 repurposes the plant oxygen-sensing machinery to control the transcriptional response to oxidative stress

Plants sense reduced oxygen availability (hypoxia) through Plant Cysteine Oxidases (PCOs). Reduced PCO activity in hypoxia, as seen during submergence, stabilises Group VII Ethylene Response Factors (ERFVIIs), master regulators of adaptive metabolic and anatomic responses. Equally important is timely arrest of these responses upon reoxygenation, assumed to occur through ERFVII degradation. Reoxygenation involves reactive oxygen species (ROS) production. Here, we report that instead of degradation, reoxygenation results in ERFVII nuclear stabilisation, an effect mimicked by direct H2O2 treatment. Interestingly, typical hypoxia marker genes are repressed while genes involved in ROS homeostasis and oxidative stress protection are upregulated. Using in planta, heterologous and biochemical assays, we reveal that ROS-related ERFVII stabilisation is caused by PCO inactivation. Stabilised ERFVIIs are retained at hypoxia-responsive promoters but become repressors. Our findings suggest that by responding to both oxygen and ROS, PCOs coordinate ERFVII stability to regulate timely responses to damaging fluctuations in oxygen availability.

plant biology↗