Nitrite utilization by excised Zea mays L. roots under anaerobic conditions

Abstract

Under both aerobic and anaerobic conditions exogenously supplied nitrite was utilized by sterile excised Zea mays L. root. A slightly greater quantity of nitrite was used under aerobic conditions than under anaerobiosis. The uncoupler of oxidative phosphorylation, pentachlorophenol (PCP), diminished the utilization of nitrite under aerobic and anaerobic conditions resulting in a net accumulation of nitrite rather than a net disappearance of nitrite. Nitrite supplied together with nitrite resulted in a slight reduction in the level of nitrite utilized. Supply of exogenous nitrite had no effect on nitrate reduction under aerobic or anaerobic conditions. A net accumulation of nitrite occurs only when roots are supplied with nitrate in the absence of added nitrite. However, the level of nitrite accumulated under anaerobiosis, when roots were supplied with nitrate only, was found to be a fraction of the quantity of nitrite utilized when roots were supplied with nitrite under anaerobiosis. Nitrate utilization far exceeded the level of nitrite accumulated under anaerobiosis when roots were supplied with nitrate only.