Plants deficient in elemental nitrogen, often show its effect on...

Nitrogen is the essential nutrient element required by plants in the greatest amount. It is absorbed mainly as NO_{3}^{–}, though some are also taken up as NO_{2}^{–}or NH_{4}^{+}. Nitrogen is required by all parts of a plant, particularly the meristematic tissues and the metabolically active cells. Nitrogen is one of the major constituents of proteins, nucleic acids, vitamins and hormones.