Water potential and nitrogen metabolism in seedlings of balsa wood (Ochroma pyramidale (Cav. Ex Lam) Urb.) subjected to water deficit stress and flooding

This research aimed to evaluate the metabolic responses of nitrogen forward the effects of water stress and flooding in young plants of pau-de-balsa. The experimental design was completely randomized in a factorial arrangement (3x4) in three water conditions: control (irrigated), water deficit and flooding in four periods of evaluation (0, 4, 8 and 12 days), with 5 repetitions. The water potential, nitrate, nitrate reductase and glutamine synthetase of reduced around 10; 5; 12.5 and 2.69 respectively in stressed plants, which did not occur with Free Ammonia which increased 1.72 in its concentration. The Amino Acid Concentrations, Glycine Betaine and Proline increased in plants under water deficit around 1.9; 2.13 and 2.5 respectively. However in flooding condition these variables significantly decreased from the 4th day of the experiment. Protein content decreased in plants under water stress and flooding about 1.9 and 4.37 respectively. Therefore, the analyzes carried out revealed that the pau-de-balsa plants are highly sensitive to flooding and tolerant to water stress.