Role Source deficiency and Symptoms of Macronutrients in Plants

 

MACRO NUTRIENTS 

Macronutrients are required by plants in large quantities therefore they are involved in major functioning in the plant body.

Macronutrients in plants are nutrients that provide energy to the plants and are required in larger amounts to maintain their development and growth. These are the most important elements required for crops.

NITROGEN

Absorption  

Plants absorb Nitrogen in the form of Nitrates and Nitrite but sometimes plants absorb in the form of ammonium ions.

Role 

Nitrogen is one of the major constituents of proteins, nucleic acids, vitamins and hormones.

Deficiency 

Deficiency of Nitrogen in plants causes stunted growth. Inhibiting the Growth of younger leaves and shoots. plants become pale green to yellowish-green because Deficiency of nitrogen causes the inhibition  of the process of  chloroplast and chlorophyll synthesis. 

Symptoms 

The whole plant looks pale to yellowish green. There is early senescence of older leaves.

Increased root growth and stunted shoot growth creates low  ratio of shoot and root .

 PHOSPHORUS 

Absorption

Phosphorus is absorbed by the plants from soil in the form of phosphate ions in the form of hydrogen phosphate.

Role

Phosphorus is a constituent of cell membranes, certain proteins and is required for all phosphorylation reactions and constituent of ATP.

Deficiency

Deficiency of Phosphorus causes the poor absorption of  mineral nutrients. Distorted  photosynthetic system and  disturbance in metabolism of antioxidants.

Symptoms

Plants  turn dark green in color. Leaves and stems may appear shorter in size. Older leaves are affected soon  and  turn into purple colour. may acquire a purplish discoloration. In severe cases  leaf tips are  brown and die  due to the weakness..

CALCIUM

Absorption

Plant absorbs calcium from the soil in the form of calcium ions. 

Role

During cell division, Calcium is used in the synthesis of cell wall formation of mitotic spindle.Calcium activates certain enzymes as cofactor and is involved in regulation of metabolic activities.

Deficiency

 Deficiency of calcium is  seen primarily on young leaves and tissues therefore the growth is inhibited. Plants have a bushy appearance. The young leaves bear brown chlorotic spots. which spread to eventually unite in the center of the leaves. Veins are  dark  brown, and completely necrotic. The root tip also does not show normal and people growth in calcium deficient plants.

Symptoms

The formation of meristematic tissue does not take place. . Typically Death of root tips may take place.Its deficiency also causes chlorosis and dark veins in leaves.

MAGNESIUM

Absorption

Magnesium is absorbed by plants in the form of divalent ions.

Role

It activates the enzymes of respiration, photosynthesis and are involved in the synthesis of DNA and RNA.

Deficiency

Magnesium deficiency causes deleterious changes in  phenotypic and physiological expressions. It disturbs the process of homeostasis. It also controls the transportation   and interactions between the  ions, and sometimes disturbs the secondary metabolism.

Symptoms

 The  symptoms of Magnesium deficiency are first  seen at the  lower leaves. Symptoms are more severe on the lower leaves because magnesium is moved to the new growth. Deficiency symptoms consist of interveinal chlorosis leaf veins stay green while the regions between them turn yellow.

SULPHUR

Absorption

Plants obtain sulphur in the form of sulphate.

Role 

Sulphur is present in cysteine and methionine and is the main constituent of several 

coenzymes, vitamins.

Deficiency

Sulphur deficiency affects the formation of chlorophyll and  protein. It delays the  plant growth and development as well as maturity.

Symptoms.

Sulphur deficiency symptoms sometimes are similar to the symptoms of nitrogen. The leaves become pale-yellow or light-green.The  sulphur deficiency symptoms  are  appeared  first on the younger leaves.

In addition to this, retarded growth, immature cereals,poor nodulation in legumes and poor nitrogen-fixation  are other symptoms of sulphur deficiency.

POTASSIUM

Absorption

Plants absorb potassium in its ionic form, K+. It is the second important macronutrient after Nitrogen and called Quantity nutrients.

Role

Potassium regulates the opening and closing of stomata, 

It  activates the enzymes that are essential for production of Adenosine Triphosphate. Potassium is needed for the formation of protein and starch. It makes active many growth related enzymes active in plants.

Deficiency

Deficiency of Potassium lowers the resistance powers of plants.It also affects absorption of nutrients by the roots.

Symptoms

Symptoms of potassium deficiency are first seen on the lower portion of the plant.  chlorosis  also appears at the leaf  followed by necrosis .