Effect of Mineral Deficiencies upon the Synthesis of Riboflavin and Ascorbic Acid by the Oat Plant

Open Access
Publisher Website
Google Scholar
Abstract
Oat plants (Avena sativa, var. Ill. 30-2088) were grown on gravel in complete nutrient solns. for 21 days, then transferred to solns. deficient in one of the major nutrients, K, Ca, Mg, NO3, SO4, and PO4. A control group was maintained on the complete soln. The plants were cut at the onset of jointing (42 days), divided into leaf blades, stems, and roots, and dried at 70[degree]C. Fresh and dry wt., riboflavin, ascorbic acid (on fresh tissue), K, Ca, Mg, Fe, N, and P were detd. Visual deficiency symptoms were noted only in the [long dash] Ca, [long dash] Mg, and [long dash] NO3 plants but all groups were low in the element omitted from their soln. The ascorbic acid cone, in the leaves of the [long dash] K and [long dash] Mg plants was much higher than in the control leaves. Ascorbic acid values in mg. % dry wt. were: control, 440; [long dash] K, 635; [long dash] Mg, 814. The riboflavin cone, in all parts of plants grown on the deficient solns. was lower than in the control plants. The leaves, where the bulk of the riboflavin was located, showed the greater differences. A lower riboflavin cone, in all plant parts was produced by [long dash] NO3 than by any other treatment. Data on the leaves from the 7 treatments showed a highly significant correlation between N cone, and riboflavin cone. Growth of leaves and stems in terms of dry substance was significantly correlated with riboflavin cone.