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TOLERANCE MECHANISMS IN Hymenaea courbaril L. and Jatropha curcas L. plants AS A RESPONSE TO WATER DEFICIT AND CONTAMINATION BY OIL DERIVATIVES

MECANISMOS DE TOLERÂNCIA EM PLANTAS DE Hymenaea courbaril L. e Jatropha curcas L. EM RESPOSTA AO DEFICIT HÍDRICO E CONTAMINAÇÃO POR DERIVADOS DE PETRÓLEO

ABSTRACT

Accidents that occur during the transport of oil and its derivatives have been one of the primary causes of environmental pollution in recent decades. Studies on changes in plant physiology caused by these pollutants are scarce, and the effects on plant metabolism are little known. As such, the aim of the present study was to analyze the effect of soil contaminated with diesel fuel on the physiology of young Hymenaea courbaril L. and Jatropha curcas L. plants. The following variables were analyzed: gas exchanges, photosynthetic pigments, chlorophyll index (SPAD) and protoplasmic damage. The treatments used were: T0 - control (100% of maximum soil water holding capacity - contamination-free soil), T1 and T2 (50% of maximum soil water holding capacity + addition of 23 mL and 46 mL of diesel fuel, respectively) and two assessment times (3h and 192h after contamination). Significant differences in gas exchanges were observed for both species 3h after diesel fuel application. For photosynthetic pigments and the chlorophyll index, increases were found 3h and 192 h after imposed stress, for both species. A significant rise in electrolyte leakage was observed, more pronounced in J. curcas plants after 192h, for treatments T1 and T2 compared to T0. These findings show the potential of species to acclimate themselves to adverse conditions, and should be considered in recovery programs for environments degraded by oil derivatives.

Keywords:
Stomatal behavior, Ddiesel fuel; Soil contamination

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