The Effect of Alterations in Nitrogen Supply on Nitrogen Metabolism of Hydroponically Grown Maize Plants, Zea mays L.

Abstract

Summary Maize plants hydroponically grown on nutrient solution were used to study the effect of alterations in N supply on N concentrations in the organs as related to the ability of biomass production. Omission of nitrate from the nutrient solution induced in the vegetative organs a breakdown of nitrogenous compounds which were partly redistributed towards the ears. These processes took place more at the expense of membrane proteins than of the buffer-soluble proteins and resulted in N concentrations lower than the theoretical minimum; then the biomass production stopped. Re-supply of nitrate to young N-starved plants induced an increase of N concentrations in all plant parts and the resumption of biomass production. The newly produced amount of membrane proteins was larger than that of buffer-soluble proteins. However, the ratio of buffer-soluble to membrane protein concentrations in mature leaves did not return to the original value. It was concluded that re-supply of nitrate resulted in a recuperation of N-starved plants to a restricted extent.