Nitrate is reported to improve tolerance of plants towards oxygen deficiency enabled by waterlogging of the root system, but the mechanism underlying the phenomenon remains poorly understood. We studied the metabolism of nitrate in roots exposed to hypoxia, using soybean plants growing in a hydroponic system after suspending aeration and covering the surface of the nutrient solution with mineral oil. Nitrate depletion from the medium was more intense under hypoxia than normoxia, but in the presence of chloramphenicol, consumption under hypoxia was significantly reduced. Nitrite accumulated in the medium in the state of hypoxia and this effect was partially eliminated by chloramphenicol. Nitrate consumption sensitive to chloramphenicol was attributed to... |