Nitrogen compounds, proteins and amino acids in corn subjected to doses of aluminum

Corn (Zea mays L.) is highly adaptable, but it has difficulties in expressing its productive potential in soils with high aluminum content, since this element is directly related to high acidity in the soil. The objective of this study was to evaluate the nitrogen compounds, proteins and amino acids of two corn cultivars subjected to increasing doses of aluminum. The experiment was carried out in a greenhouse using one of the corn plants from varieties BRS 106 and BRS 4157. The experimental design was entirely randomized, in a factorial design of 5x2, and the factors were composed of five doses of Al3+ (0; 50; 100; 150 and 200 mmol L-1), with five repetitions. The variables analyzed were the concentration of nitrate, the activity of the nitrate reductase, concentration of ammonium, amino acids and proteins. There was a decrease in nitrate, activity of the Reductase enzyme of the Nitrate and protein in the highest dose of aluminum (200 mmol L-1) for both cultivars. There was an increase in ammonium and amino acids in the leaves of cultivars BRS 106 and BRS 4157. Cultivars BRS 106 and BRS 4157 were affected by the increasing doses of aluminum, but cultivar BRS 106 showed to be more tolerant. Key words: Aluminum, toxicity, corn, metabolism.