Responses of young plants of Vachellia farnesiana to drought

Water availability in soil modulates plant acclimatisation responses in different habitats. In this study, we evaluated the effect of water deficit on the physiological, biochemical and growth responses of Vachellia farnesiana. Open environment experiment was conducted during 90 days and two conditions of hydration were tested: full hydration (H) and water deficit (WD) at 25% of field capacity. The relative water content (RWC) of the leaves under WD showed a 30.2% decrease (P < 0.01), compared with the hydrated plants at 30 days. A decrease in the RWC led to decrease in the osmotic potential (Psi(s)), quantum yield of PSII (F-v/F-m) and lesser content of chlorophylls a and b under WD. A greater carotenoid content and simultaneous increase in the content of proline, H2O2 and phenolic compounds of the leaves was also observed in WD. Water deficit also promoted differences in the nitrogen, phosphorus, and potassium content of the leaves when compared with hydrated plants. Although they showed growth deficit, plants of V. farnesiana demonstrated resistance to WD through physiological and biochemical adjustments.