MINERAL NUTRITION

1. MINERAL NUTRITION Plant Physiology 2011

2. Macronutrients

3. Nitrogen Source: • The chief source is the soil. • Plants absorbs it either in the form of nitrate or ammoniacal salts. • Some bacteria and heterocysts containing blue green algae fix the nitrogen of the atmosphere. Functions: • Nitrogen is an essential constituent of different proteins and nucleic acids

4. Deficiency: • The chlorotic symptoms in leaf. • A light red cast can also be seen on the veins and petioles. • The older mature leaves gradually change from their normal characteristic green appearance to a much paler green. • As the deficiency progresses these older leaves become uniformly yellow (chlorotic). • Branching is reduced in nitrogen deficient plants resulting in short, spindly plants. • The yellowing in nitrogen deficiency is uniform over the entire leaf including the veins. • In some plants the underside of the leaves and/or the petioles and midribs develop traces of a reddish or purple color.

5. Nitrogen

6. Sulfur. Source: • Sulphur is available to plants in the form of soluble sulphate of soil. Fuction: • Sulphur is the constituent of amino acids ( cystein and methionine), vitamin (B1), co-enzyme A and volatile oils. • The characteristic odour of crucifer plants, onions, garlic and tropeolae is due to sulphur as a constituent of volatile oils. • Sulphur affects an increase in nodule formation in root of leguminous plants. • Sulphur adversely affects chlorophyll synthesis.

7. Deficiency symptoms • leaves show a general overall chlorosis while still retaining some green color. • The veins and petioles show a very distinct reddish color. • sulfur deficiency are very similar to the chlorosis found in nitrogen deficiency. • However, in sulfur deficiency the yellowing is much more uniformover the entire plant including young leaves. • The reddish color often found on the underside of the leaves and the petioles has a more pinkish tone and is much less vivid than that found in nitrogen deficiency. • with advanced sulfur deficiency brown lesions and/or necrotic spots often develop along the petiole, and the leaves tend to become more erect and often twisted and brittle.

8. Sulphur deficiency

9. Phosphorus Source: • as H3PO4 and HPO4. Functions. • It promotes healthy root growth and fruit ripening by helping translocation of carbohydrates. • It is an essential participating in the skeleton of plasma membrane, nucleic acids, many coenzymes and organic molecules such as ATP and other phosphorylated products. • It plays an important role in the energy transfer reaction and in oxidation reduction process.

10. Deficiency symptoms • Phosphorus-deficient leaves show some necrotic spots. • A major visual symptom is that the plants are dwarfed or stunted. • Some species such as tomato, lettuce, corn and the brassica develop a distinct purpling of the stem, petiole and the under sides of the leaves. • Under severe deficiency conditions there is also a tendency for leaves to develop a blue-gray luster. • In older leaves under very severe deficiency conditions a brown netted veining of the leaves may develop.

11. Phosphorous

12. Calcium. Source. • derived from stone or chalk rock contains a larger percentage of calcium carbonate. Function: • Calcium is the chief constituents of plants as calcium pectate of the middle lamella of the cell wall. • It provides a base for the neutralization of organic acid and is also concerned with the growing root apices. • It also acts as an activator of ATPase, some kinase, phospholipids and succinatedehydrogenase. • It is essential for fat metabolism. • formation of membrane, carbohydrate metabolism, nitrate assimilation, binding of nucleic acids with proteins.

13. Deficiency symptoms • Calcium-deficient leaves show necrosis around the base of the leaves. • Classic symptoms of calcium deficiency include blossom-end rot of tomato (burning of the end part of tomato fruits), tip burn of lettuce and death of the growing regions in many plants. • All these symptoms show soft dead necrotic tissue at rapidly growing areas, which is generally related to poor translocation of calcium to the tissue.

14. Calcium

15. Potassium Source: • potassium is widely distributed in soil minerals. Functions. Its utilisation in plant is concerned with • enzyme action • synthesis of nucleic acid and chlorophyll • oxidative and photophosphorylation • translocation of solutes etc.

16. Deficiency symptoms potassium • Leaves show marginal necrosis (tip burn), • others at a more advanced deficiency status show necrosis in the interveinal spaces between the main veins along with interveinal chlorosis. • The onset of potassium deficiency is generally characterized by a marginal chlorosis progressing into a dry leathery tan scorch on recently matured leaves.

17. Potassium

18. Magnesium Source : • magnesium occurs as carbonate fairly similar to that of calcium Functions. • It is a constituent of chlorophyll and, therefore, essential for the formation of this pigment. • It acts as a phosphorous carrier in the plant, particularly in connection with the formation of seeds of high oil contents which contain compound lecithin. • Magnesium is essential for the synthesis of fats and metabolism of carbohydrates and phosphorous. • It is required to combine two subunits of ribosomes.

19. Magnesium • The Mg deficient leaves show advanced interveinal chlorosis, with necrosis developing in the highly chlorotic tissue. • In its advanced form, magnesium deficiency may superficially resemble potassium deficiency. • In the case of magnesium deficiency the symptoms generally start with mottled chlorotic areas developing in the interveinal tissue. • The interveinallaminae tissue tends to expand proportionately more than the other leaf tissues, producing a raised puckered surface, with the top of the puckers progressively going from chlorotic to necrotic tissue

20. Magnesium

21. Microelements

22. Iron Source: • It is fairly present in the form of its oxides giving red or brown colour to the soil. • In well-irrigated areas ferric compounds are predominantly found and in water logged soils, ferrous compounds are formed. Functions: • Iron also acts as a catalyst and electron carrier in respiration. • Iron is a constituent of cytochromes, ferredoxin, catalase, peroxidase and etc. • It also acts as an activator of nitrate reductase and aconitase.

23. Deficiency symptoms • These iron-deficient leaves show strong chlorosis at the base of the leaves with some green netting. • The most common symptom for iron deficiency starts out as an interveinal chlorosis of the youngest leaves, evolves into an overall chlorosis, and ends as a totally bleached leaf. • The bleached areas often develop necrotic spots

24. Iron

25. Manganese. Source: • Like iron, the oxide forms of manganese are common in soil but the more highly oxidised form ( manganese dioxide) are of very low availability to plants. Functions: • It acts as an activator of some oxidases, peroxidises, dehydrogenases, kinases and decarboxylases etc. • And is essential for the formation of chlorophyll. • It also decreases the solubility of iron by oxidation hence in certain cases abundance of manganese leads to iron deficiency in plants.

26. Deficiency symptoms • In leaves light interveinal chlorosis developed under a limited supply of Mn. • The early stages of the chlorosis induced by manganese deficiency are somewhat similar to iron deficiency. • As the stress increases, the leaves take on a gray metallic sheen and develop dark freckled and necrotic areas along the veins. • A purplish luster may also develop on the upper surface of the leaves.

27. Manganese

28. Copper Source: Copper is found in small quantities in soils Functions: • Its specific function in plants largely remains to be determined but its role as a catalyst and regulator is quite evident. • It is a constituent of ascorbic acid oxidase, laccase, tryosinase, phenoloxidase, plastocyanin etc. • And is essential for photosynthesis, respiration and carbohydrate/nitrogen balance.

29. Deficiency symptoms • copper-deficient leaves are curled, and their petioles bend downward. • Copper deficiency may be expressed as a light overall chlorosis along with the permanent loss of turgor in the young leaves. • Recently matured leaves show netted, green veining with areas bleaching to a whitish gray. • Some leaves develop sunken necrotic spots and have a tendency to bend downward. • Trees under chronic copper deficiency develop a rosette form of growth. • Leaves are small and chlorotic with spotty necrosis.

30. Copper

31. zinc Source • Like copper, it is also found in soils in very small quantities and largely results from concentration and addition from growing plants and added residue. Functions. • little is known about its function like that of iron, manganese or copper • but it is a component of enzymes like carbonic anhydrogenase, alcohol dehydrogenase, Lactic acid dehydrogenase, glutamicdehydrogenase, alkaline phosphatise, carboxypeptidase, etc. • It has been found essential for carbon dioxide evolution and utilization, carbohydrate and phosphorous metabolism and synthesis of RNA and auxins. • A close relationship is found between zinc and chlorophyll formation.

32. Deficiency symptoms • Leaves show an advanced case of interveinal necrosis. • In the early stages of zinc deficiency the younger leaves become yellow and pitting develops in the interveinal upper surfaces of the mature leaves. • Guttation is also prevalent. • As the deficiency progress these symptoms develop into an intense interveinal necrosis

33. zinc

34. Molybdenum Source: • It is found widely distributed in small amounts in soils and plants • its higher concentration occurs in mineral oils and coal ashes. Functions: • It is an important constituent of the nitrate reducatse system. • It also acts as an activator of some dehydrogenase and phosphatase and as cofactors in the synthesis of ascorbic acid. • It is found necessary to the nodule formation in legumes for the fixation of atmospheric nitrogen.

35. Molybdenum. • leaves show some mottled spotting along with some interveinal chlorosis. • In the case of cauliflower, the lamina of the new leaves fail to develop, resulting in a characteristic whiptail appearance. • In many plants there is an upward cupping of the leaves and mottled spots developing into large interveinal chlorotic areas under severe deficiency. • At high concentrations, molybdenum has a very distinctive toxicity symptom in that the leaves turn a very brilliant orange.

36. Molybdenum

37. Boron Source. • Boron occurs in rocks and marine sediments. • It is absorbed in the form of borate ions. Function. • It is necessary for translocation of sugars • is involved in the reproduction and germination of pollens. • It is concerned with water reactions in cells and regulate the intake of water into the cell.

38. Deficiency symptom • boron-deficient leaves show a light general chlorosis.

39. Deficiency symptoms

40. Deficiency symptoms of Chloride • leaves have abnormal shapes, with distinct interveinal chlorosis. • The most common symptoms of chlorine deficiency are chlorosis and wilting of the young leaves. • The chlorosis occurs on smooth flat depressions in the interveinal area of the leaf blade. • In more advanced cases there often appears a characteristic bronzing on the upper side of the mature leaves.

41. Chloride

42. Reference • Lincoln Taiz and Eduardo Zeiger, Plant Physiology, Fifth Edition.