Manganese (Mn⁺²) ions connects ATP with complexes enzymes (phosphor transferase· and phosphokinase). Dehydrogenase and Decarboxylase in the Krebs cycle (TCA) are also activated by Mn⁺². Manganese plays an important role in chlorophyll production and its presence is essential in Photo system II, also involved in cell division and plant growth. RNA polymerase is activated by manganese.  Manganese has an effective role in lipids metabolism, and due to effective role of manganese in the nitrate reduction enzymes, nitrate will accumulation in leaves which are facing with manganese deficiency.  Moreover amount of lignin in the plant will decline due to manganese deficiency, that this reduction is more severe in the roots, this matter is very important especially to reduction resistance the roots of plants to fungi infecting. Manganese deficiency  symptoms  first appear  on  younger leaves;  because dynamics  of  these elements  in  different  plant  tissues  is  limited  (manganese  isn’t  a  mobile element).