Abstract: White clover (Trifolium repens ‘Haifa’) was selected as experimental material in this study,and effects of seeds soaking with gamma-aminobutyric acid (GABA) on germination and tolerance to aluminium (Al³⁺) stress were studied. The results showed that 1 mmol·L^-1 Al³⁺ solution significantly inhibited seeds germination,and the damage becomes more obvious with the increase of Al³⁺ concentration. The germination and root length of seeds soaking with GABA significantly increased under Al³⁺ stress with the most obvious effect under 4 mmol·L^-1 Al³⁺ stress. The antioxidant enzyme activity and non-enzymatic antioxidants content of seeds soaking with GABA significantly increased as well,thereby reducing oxidative damage effectively and improving cell membrane stability during germination under Al³⁺ stress. In addition,seeds soaking with GABA also significantly increased genes expression of dehydrins under Al³⁺ stress. Therefore,GABA-induced Al³⁺ tolerance could be related to the enhancement of antioxidant defense to reduce oxidative damage caused by stress and the up-regulation of dehydrins genes expression during white clover seeds germination.

Key words: Abiotic stress, Antioxidant, Oxidative damage, Dehydrins, AsA-GSH cycle

摘要： 本研究以‘海发’白三叶（Trifolium repens ‘Haifa’）为供试材料，研究伽马氨基丁酸（γ-aminobutyric acid，GABA）浸种预处理对铝（aluminium，Al³⁺）胁迫下白三叶种子萌发及耐Al³⁺性的影响。研究表明，1 mmol·L^-1的Al³⁺溶液即能显著抑制白三叶种子的萌发，随着Al³⁺浓度的加大这种抑制作用也越明显。GABA浸种预处理显著提高Al³⁺胁迫下白三叶种子的萌发和根长，且在4 mmol·L^-1的Al³⁺胁迫下效果最明显。GABA浸种也显著提高Al³⁺胁迫下抗氧化酶活性及非酶抗氧化物质含量，从而有效降低Al³⁺胁迫导致的氧化伤害，提高细胞膜稳定性。此外，GABA浸种也进一步上调了Al³⁺胁迫诱导的脱水蛋白基因表达。因此，GABA提高Al³⁺胁迫下白三叶种子的萌发可能与增强抗氧化防御以减轻胁迫造成的氧化损伤及上调脱水蛋白基因表达有关。

关键词: 非生物胁迫, 抗氧化, 氧化伤害, 脱水蛋白, 抗坏血酸-谷胱甘肽循环