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 (Ψs), quantum yield of PSII (Fv/Fm) 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.

中文翻译：

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瓦切利亚法尼西亚纳幼苗对干旱的响应

土壤中的水分可利用性调节不同生境中的植物适应环境。在这项研究中，我们评估了水分亏缺对 Vachellia farnesiana 生理、生化和生长反应的影响。开放环境试验在 90 天内进行，测试了两种水化条件：完全水化 (H) 和 25% 田间容量的缺水 (WD)。与 30 天的水合植物相比，WD 下叶片的相对含水量 (RWC) 显示出 30.2% 的下降 (P < 0.01)。RWC 的减少导致渗透势 (Ψs)、PSII 的量子产率 (Fv/Fm) 和 WD 下叶绿素 a 和 b 的含量降低。在 WD 中还观察到更高的类胡萝卜素含量和同时增加的脯氨酸、H2O2 和叶酚类化合物的含量。与水合植物相比，水分不足还促进了叶片氮、磷和钾含量的差异。尽管 V. farnesiana 的植物表现出生长缺陷，但它们通过生理和生化调整表现出对 WD 的抗性。