Plants take up and assimilate nitrogen (N) in the form of nitrate (NO3–) or ammonium (NH4+), or a combination of both. When oxygen availability is reduced (hypoxia), plants need to generate energy to survive and protect themselves against the hypoxia-induced damage.
Wany et al. investigate the role of NO3– or NH4+ on increasing energy efficiency under hypoxia in Arabidopsis. They find that hypoxic stress under NO3– nutrition leads to increased nitrate reductase activity, nitric oxide (NO) production, class 1 phytoglobin gene expression, and in turn ATP production. These effects were reduced under NH4+ nutrition. The results indicate that NO3–nutrition influences multiple factors in order to increase energy efficiency under hypoxia.