Mechanism of Action of Micronutrient Elements in Enzyme Systems

Effects of copper sulphate and cobalt chloride on <i>in vitro</i> performances of traditional indica rice (<i>Oryza sativa</i> L.) varieties in Sri Lanka

“…Micronutrients in plant cells, especially copper, iron, manganese and zinc, are important in the process of respiration where iron and copper are the functional parts of some oxidative enzymes contained in plant tissues (Sumner and Somers, 1953). Furthermore, manganese and zinc are essential cofactors in the process of glycolysis and Krebs' cycle (MacElroy and Nason, 1954). Therefore, these elements trigger the rate of respiration.…”

The effect of nutrient deficiencies on phosynthesis and respiration in spinach

“…The shoot-root ratio was increased by deficiencies of manganese and boron and decreased by deficiencies of nitrogen, phogphoru'~, potassium and molybdenum. Deficiencies (5) (4) 5.06 (4) 1353 (4) 2.60 (4) (5) 2.77 (5) 369 (5) 2.86 (5) (8) 1.93 (9) 270 (8) 2.44 (8) (12) 2.76 (12) 669 (12) 3.08 (12) (2) 2.49 (3) 253 (3) 3.58 (3) (6) 2.40 (6) 343 (8) 2.07 (6) (9) 2.82 (9) 604 (9) 3.35 (9) (13) 2.84 (13) of magnesium, iron, sulphur, calcium, copper and zinc had no effect. The insoluble nitrogen content of the plant was increased by deficiencies of potassium, magnesium, calcium, copper and boron and reduced by deficiencies of nitrogen and molybdenum.…”

Preliminary Observations on Cobalt and Vitamin B12 in Fresh Water1

“…The biological signijkance OF cobalt Cobaltous ion is known to act as an altcrnativc cofactor for magnesium or mangancsc in a number of enzyme systems (McElroy and Nason 1954), but there has never been any conclusive cvideilce that the clement is required by any organism except as a component of the structure of vitamin BID The need for vitamin T312 is widespread in nature and one specialist in the field (Marston 1956) has recently suggcstcd that all animals rcquirc the vitamin.…”