Nitrogenous compounds in hog plum plants (Spondia mombin L.) under water deficit

The hog plum tree is a species exploited extractively, but this information is not included in official statistics, despite the socioeconomic relevance of the species in the North and Northeast of Brazil. The present study aimed to analyze physiological and biochemical processes in Spondia mombin L. plants under two water regimes. The experiment was conducted in a greenhouse at the Federal Rural University of the Amazon, Belem, PA. The experimental design was completely randomized with two water conditions: control and water deficit, with 20 repetitions totaling 40 experimental units, where each experimental unit consisted of one (1) plant/pot. Moderate/severe water deficit was simulated by suspending irrigation of the seedlings, respectively, for a 15-day period. There were reductions in the levels of water potential, nitrate, nitrate reductase and proteins, while the values for ammonium, glutamine synthetase, amino acids, proline and glycine betaine had a significant increase in plants under water stress compared with control plants. Young hog plum plants under water deficit undergo changes in nitrogen metabolic pathways. These changes are indicative of intolerance to extremely dry environments.   Key words: Nitrate content, osmoregulator, tolerance, amino acid.