Mecanismos bioquímicos, fisiológicos e crescimento em plantas de Dipteryx odorata (aubl.) willd (fabaceae) em duas condições hídricas.

Abstract

The objective of this study was to evaluate the growth and ecophysiological and biochemical mechanisms of tolerance to water stress, especially with regard to the assimilation of carbon and nitrogen concentrations of organic compounds and enzymes involved in this process. The experiment was conducted in a greenhouse at the Universidade Federal Rural da Amazonia (UFRA) located in Belém-Para, from March 2015 to July 2015. Species seedlings were used Dipteryx odorata Aubl (Cumaru). The experimental design was completely randomized in split plot in time (four times evaluation and two water conditions: control and drought stress), with 5 repetitions, totaling 40 experimental units, where each experimental unit was composed of a plant / pot. The imposition of water deficit was obtained by withholding water at 0 (zero days of water deficit), time 1 (7 days of water deficit), time 2 (14 days of drought) and time 3 (21 days water deficit). It was applied to analysis of variance in the results and when there was a significant difference to the averages were compared by Tukey test at 5% significance level, and statistical analyzes performed by ASSISTAT Version 7.7 beta program. The relative water content was reduced dramatically as increasing the time of stress in plants. The transpiration data showed decreased and increased stomatal resistance in plants grown without irrigation, with the increase of water stress time, with more pronounced reductions in the 14th and 21st day of water stress. Dried pasta sheet total and the diameter presented significant difference between treatments but the biomass of root, stem and height had no statistically significant differences. The results showed that there was a significant decrease to chlorophyll A, and ammonium nitrate, however, had to chlorophyll B, chlorophyll and proline to the plants under water stress. There was an increase in electrolyte leakage with 22.74% for roots and 39.55% for leaves. The SOD, CAT showed a significant increase in the left of the 14th day of the experiment, and APX in the 7 day experiment. The Cumaru loses water excessively under disability and that impaired their growth and metabolism causing the plant sought changes to maintain vital processes for that the tonka bean increased the proline compound, closed stomata, decreased sweating. The Cumaru presented response to increased reactive oxygen species by raising the antioxidant enzymes SOD, CAT and APX