In which one of the following is nitrogen not a constituent?

Idioblasts are parenchyma cells which store tannins, resins etc. it is an isolated cell found in cells of plant tissue, in the middle of homogenous group of cells. Idioblastic parenchyma have various functions such as storage of reserves, excretory materials, pigments, and minerals. Related Theory Idioblasts can contain biforine cells that form crystals.