Manganese is mainly absorbed in the form of Mn2+ and a major member of the photosynthetic oxygen-oxygen complex, and when the manganese deficiency is inhibited. Also is an essential element for the formation of chlorophyll and maintaining the normal structure of chlorophyll. When manganese or nitric acid reduction of the auxiliary factors, manganese deficiency when the nitric acid cannot be reduced to ammonia, plants cannot synthesize amino acids and protein.
When the manganese is not formed, the chlorophyll can not form chlorophyll, the green leaves are faded, but the veins remain green. This is the main difference between manganese deficiency and iron deficiency.