Salinity, one of the catastrophic abiotic stresses that uces wheat production around the globe. Abscisic acid (ABA) is a stress phytohormone as a signaling molecule that led us to investigate its potential to improve morpho-physiological characteristics, antioxidant metabolism, and ion homeostasis in wheat (Triticum aestivum L.) seedlings grown under salinity stress (0, 50, and 100 mM NaCl). The findings suggested that salt-induced toxicity significantly (P < 0.05) damaged root morphological characteristics, plant growth, photosynthetic pigments, and water contents, while trigger the oxidative injury, Na${}^{+}$ ion accumulation and uptake in wheat leaf and root tissues with the increasing NaCl concentration in the nutrient media. However, root-zone supply of ABA (0, 5, and 10 $\mathrm{\mu }$M) prominently alleviated salt induced phytotoxicity. The 10 $\mathrm{\mu }$M concentration of ABA promoted shoot (81.7%) and root (102.1%) dry weight, root length (38.2%), Chl. a (65.3%), Chl. b (149.0%), carotenoids (95.7%) and membrane damage (36.7%) when NaCl was added at 100 mM, relative to the corresponding treatment without ABA. Moreover, ABA (10 $\mathrm{\mu }$M) supply decreased Na${}^{+}$ ion uptake (root to leaf) due to reduced transpiration rate (81.1%), and thereby ameliorated oxidative injury by ucing leaf malondialdehyde (MDA) and ${\mathrm{H}}_2$O₂ contents by 36.8% and 29.9%, respectively, at 100 mM NaCl stress, relative to the similar treatment without ABA. In addition, the activities of catalase (CAT), superoxide dismutase (SOD), and ascorbate peroxidase (APX) were upregulated by 143.9%, 20.2%, and 19.5% in leaves and by 144.9%, 23.4% and 41.1% in roots respectively, with 10 $\mathrm{\mu }$M ABA application under 100 mM salinity stress, compa to the 100 mM NaCl treatment without ABA. Conclusively, this study proposed that root-zone ABA application promoted salinity tolerance in wheat seedlings and could be a practical approach for wheat production in salt-affected regions to ensure food security.

盐度是导致全球小麦生产的灾难性非生物胁迫之一。脱落酸 (ABA) 是一种胁迫植物激素，作为一种信号分子，促使我们研究其改善盐胁迫下生长的小麦 ( Triticum aestivum L.) 幼苗的形态生理特征、抗氧化代谢和离子稳态的潜力(0, 50和 100 mM 氯化钠）。研究结果表明，盐诱导的毒性显着（P < 0.05）破坏了根系形态特征、植物生长、光合色素和水分含量，同时引发氧化损伤，Na${}^{+}$随着营养培养基中 NaCl 浓度的增加，小麦叶和根组织中的离子积累和吸收。然而，根区 ABA（0、5 和 10$\mathrm{\mu }$M) 显着减轻盐诱导的植物毒性。10$\mathrm{\mu }$ABA 的 M 浓度促进了芽 (81.7%) 和根 (102.1%) 的干重、根长 (38.2%)、叶绿素。a (65.3%), Chl. b (149.0%)、类胡萝卜素 (95.7%) 和膜损伤 (36.7%)，当添加 100 mM NaCl 时，相对于没有 ABA 的相应处理。此外，ABA (10$\mathrm{\mu }$M) 供应减少 Na${}^{+}$ 由于蒸腾速率降低（81.1%），离子吸收（根到叶），从而改善叶丙二醛 (MDA) 和 ${\mathrm{H}}_2$相对于没有 ABA 的类似处理，在 100 mM NaCl 胁迫下，O ₂含量分别增加了 36.8% 和 29.9%。此外，过氧化氢酶（CAT）、超氧化物歧化酶（SOD）和抗坏血酸过氧化物酶（APX）的活性在叶片中分别上调了 143.9%、20.2% 和 19.5%，在根中分别上调了 144.9%、23.4% 和 41.1% , 与 10$\mathrm{\mu }$M ABA 在 100 mM 盐度胁迫下的应用，与没有 ABA 的 100 mM NaCl 处理相比较。总之，本研究提出根区 ABA 应用促进了小麦幼苗的耐盐性，可以成为盐灾地区小麦生产以确保粮食安全的实用方法。