Role of Macro and Micro Nutrients

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Essential element performs various functions. They carry out several metabolic processes in the plant cells like the maintenance of turgidity of cell, transportation of electrons, membrane permeability and enzyme activity. Essential elements also act as important constituents of the biomolecules and co-enzymes. Various functions of the macro and micro nutrients are given in the following table.

Table Showing Essential Element and Their Various Functions.

Element

Form in which the element is taken in

Region of the plant that requires the element

Function

Nitrogen, N

NO2-, NO3- or NH4+ ions

All tissues, particularly in meristematic tissues

Required for the synthesis of amino acids, proteins, nucleic acids, vitamins, hormones, coenzymes, ATP and chlorophyll

Phosphorus, P

H2PO4- or HPO42-

Young tissues from the older metabolically less active cells

Required for the synthesis of nucleic acids phospholipids, ATP, NAD, NADP. Constituent of cell membrane and some proteins

Potassium, K

K+

Meristematic tissues buds, leaves and root tips

Activates with K+/Na+ pump in active transport, anion-cation balance in the cells. Brings about opening and closing of stomata. Common in cell sap in plant cell vacuole and helps in turgidity of cells

Calcium, Ca

Ca2+

Meristematic and differentiating tissues accumulates in older leaves

Present as calcium pectate in the middle lamella of cell walls that joins the adjacent cells together. Activates enzymes needed for the growth of root and shoot tip. Needed for normal cell wall development. Required for cell division, cell enlargement

Magnesium, Mg

Mg2+

Leaves of the plant

Forms part of the chlorophyll molecule. Activates enzymes of phosphate metabolism. Important for synthesis of DNA and RNA. Essential for binding of ribosome subunits

Sulphur, S

SO42-

Stem and root tips young leaves of the plant

As a constituent of amino acids cysteine and methionine and of some proteins. Present in co-enzyme A, vitamin thiamine, biotin and ferredoxin. Increases root development. increases the nodule formation in legumes

Iron, Fe

Fe3+

Leaves and seeds

Needed for the synthesis of chlorophyll. As a constituent of ferredoxin and cytochromes. Activates the enzymes catalase

Manganese, Mn

Mn2+

All tissues. Collects along the leaf veins

Activates many enzymes of photosynthesis, respiration and N2 metabolism. Acts as electron donor for chlorophyll b. involved in decarboxylation. Reactions during respiration

Molybdenum, Mo

MoO22+

All tissues particularly in roots

Required for nitrogen fixation. Activates the enzymes nitrate reductase

Boron, B

BO33- or B4O72-

Leaves and seeds

Increases the uptake of water and calcium. Essential for meristem activity and growth of pollen tube. Involved in translocation of carbohydrates

Copper, Cu

Cu2+

All tissues

Component of oxidase enzymes and plastocyanin. Involved in electron transport in photosynthesis

Zinc, Zn

Zn2+

All tissues

Component of indoleacetic acid-a plant hormone. Activates dehydrogenases and carboxylases. Present in enzyme carbonic anhydrase

Chlorine, Cl

Cl-

All tissues

Essential for oxygen evolution in photosynthesis. Anion-cation balance in cells