Zinc (Zn) - Micronutrients
In its function in some enzyme systems, zn2+ resembles Mn2+ in that it brings about substrate binding and conformational changes in enzymes. A number of enzymes are thus activated in more or less the same way by Mn2+, Mg2+, or zn2+. Zn is actively involved in the N metabolism of the plant.
In Zn deficient plants, protein synthesis and protein levels are markedly lowered, and amino acids and amides accumulate. Zn deficiency affects protein metabolism through the inactivation of RNA polymerase. It affects structural integrity of ribosomes, and enhances RNA degradation by increasing RNase activity. Zn is also required for the synthesis of indole acetic acid from tryptophan.