SydR, a redox-sensing MarR-type regulator of , is crucial for symbiotic infection of roots.

Rhizobia associate with legumes and induce the formation of nitrogen-fixing nodules. The regulation of bacterial redox state plays a major role in symbiosis, and reactive oxygen species produced by the plant are known to activate signaling pathways. However, only a few redox-sensing transcriptional regulators (TRs) have been characterized in the microsymbiont.

Group VII ethylene response factors, MtERF74 and MtERF75, sustain nitrogen fixation in Medicago truncatula microoxic nodules.

Group VII ethylene response factors (ERF-VII) are plant-specific transcription factors (TFs) known for their role in the activation of hypoxia-responsive genes under low oxygen stress but also in plant endogenous hypoxic niches. However, their function in the microaerophilic nitrogen-fixing nodules of legumes has not yet been investigated. We investigated regulation and the function of the two Medicago truncatula ERF-VII TFs (MtERF74 and MtERF75) in roots and nodules, MtERF74 and MtERF75 in response to hypoxia stress and during the nodulation process using an RNA interference strategy and targeted proteolysis of MtERF75.

Nitric Oxide Metabolic Pathway in Drought-Stressed Nodules of Faba Bean ( L.).

Drought is an environmental stress that strongly impacts plants. It affects all stages of growth and induces profound disturbances that influence all cellular functions. Legumes can establish a symbiosis with Rhizobium-type bacteria, whose function is to fix atmospheric nitrogen in organs called nodules and to meet plant nitrogen needs.