Not much information is available to substantiate the possible role of γ -aminobutyric acid (GABA) signaling in mitigating water-deficit stress in snap bean (Phaseolus vulgaris L.) plants under semiarid conditions. Present work aims to investigate the role of exogenous GABA (foliar application; 0.5, 1 and 2 mM) in amelioration of drought stress and improvement of field performance on snap bean plants raised under two drip irrigation regimes (100% and 70% of water requirements). Water stress led to significant reduction in plant growth, leaf relative water content (RWC), cell membrane stability index (CMSI), nutrient uptake (N, P, K, Ca, Fe and Zn), pod yield and its content from protein and total soluble solids (TSS). Meanwhile, lipid peroxidation (malondialdehyde content- MDA), osmolyte content (free amino acids- FAA, proline, soluble sugars) antioxidative defense (activity of superoxide dismutase- SOD, catalase- CAT, peroxidase- POX and ascorbate peroxidase- APX) and the pod fiber content exhibited significantly increase due to water stress. Exogenous GABA application (especially at 2 mM) revealed partial normalization of the effects of drought stress in snap bean plants. GABA-induced mitigation of drought stress was manifested by improvement in growth, water status, membrane integrity, osmotic adjustment, antioxidant defense and nutrient acquisition. Furthermore, GABA application during water stress in snap bean plants resulted in improvement of field performance being manifested by increased pod yield and its quality attributes. To sum up, exogenous GABA appears to function as an effective priming molecule to alleviate drought stress in snap bean plants under semiarid conditions.

中文翻译：

---

外源γ-氨基丁酸（GABA）诱导的信号事件和与缓解菜豆干旱胁迫相关的田间表现

没有太多信息可以证实 γ-氨基丁酸 (GABA) 信号在减轻半干旱条件下短豆 (Phaseolus vulgaris L.) 植物缺水胁迫中的可能作用。目前的工作旨在研究外源 GABA（叶面施用；0.5、1 和 2 mM）在缓解干旱胁迫和改善在两种滴灌制度（100% 和 70% 的需水量）下培育的豆类植物的田间性能方面的作用）。水分胁迫导致植物生长、叶片相对含水量 (RWC)、细胞膜稳定性指数 (CMSI)、养分吸收（N、P、K、Ca、Fe 和 Zn）、豆荚产量及其来自蛋白质和总可溶性固体 (TSS)。同时，脂质过氧化（丙二醛含量-MDA）、渗透物含量（游离氨基酸-FAA、脯氨酸、可溶性糖）抗氧化防御（超氧化物歧化酶-SOD、过氧化氢酶-CAT、过氧化物酶-POX 和抗坏血酸过氧化物酶-APX 的活性）和豆荚纤维含量由于水分胁迫而显着增加。外源 GABA 应用（特别是在 2 mM 时）揭示了豆类植物中干旱胁迫影响的部分正常化。GABA 诱导的干旱胁迫缓解表现为生长、水分状况、膜完整性、渗透调节、抗氧化防御和养分获取的改善。此外，在豆类植物的水分胁迫期间施用 GABA 导致田间性能的改善，表现为豆荚产量及其质量属性的增加。总结，