Aspects of ascorbic acid and nitrate-reductase activity behaviour in plants, under polluting conditions
1994
Lacatusu, R. | Rauta, C. | Kovacsovics, B. | Lungu, M. | Plaxienco, D. (Institutul de Cercetari pentru Pedologie si Agrochimie, Bucuresti (Romania)) | Popescu, S. (Institutul de Cercetari pentru Cereale si Plante Tehnice, Fundulea (Romania))
Chemical analysis of plant samples from industrial polluted areas and from experiments carried out in the greenhouse showed changes of nitrate-reductase activity and ascorbic acid concentration. These changes depended on soil nitrate, chlorine, sulphur, pesticides and heavy metals qualities. High nitrate doses had a negative influence upon nitrate reducing processes. This was due to the molybdenum deficiency and to phosphorus diminishing absorption by plants. On these terms, increase of nitrate contents caused the diminishing of ascorbic acid concentration for the studied crops. This could be a consequence of this substance's participation to the nitrite reduction and disorders in plant nutrition with macro- and micronutrients. Likewise, the accumulation of great heavy metals quantities, chlorine and DDT in the plant nutritional medium limited the synthesis and metabolism of ascorbic acid. The sulphur application as sulphate favourably influenced the ascorbic acid. This was a cysteine effect of gluthathione biosynthesis stimulation. Cysteine and gluthathione have a protective role against the ascorbic acid oxidation.
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