胺鲜酯对铬胁迫下白三叶种子萌发特性的影响

Effects of diethyl aminoethyl hexanoate on seed germination characteristics of white clover under chromium stress

本研究以‘海发’白三叶(Trifolium repens‘Haifa’)为供试材料,研究胺鲜酯(diethyl aminoethyl hexanoate,DA-6)浸种预处理对铬(chromium,Cr^(6+))胁迫下白三叶种子萌发耐性的影响。研究表明,5 mmol·L^(−1)的Cr^(6+)溶液显著抑制白三叶种子萌发(P<0.05)。40~60 mmol·L^(−1)的DA-6可显著提高白三叶在铬胁迫下的萌发指标(P<0.05),且在60 mmol·L^(−1)浓度下效果最佳。Cr^(6+)胁迫下,DA-6浸种使种子萌发过程中游离脯氨酸和可溶性糖含量分别提高1.6和3.8倍,细胞渗透势显著降低(P<0.05),同时显著提高Cr^(6+)胁迫下抗氧化酶活性和抗坏血酸–谷胱甘肽循环代谢(P<0.05),从而有效降低Cr^(6+)胁迫导致的氧化伤害,提高细胞膜稳定性。上述结果表明,DA-6浸种可显著提高白三叶种子在Cr^(6+)胁迫下的萌发率及萌发期耐铬性,这与提高渗透调节能力及增强抗氧化防御系统密切相关。

White clover(Trifolium repens‘Haifa’)was selected as experimental material,and the effects of soaking seeds in diethyl aminoethyl hexanoate(DA-6)on tolerance of chromium(Cr)stress during germination were studied.The results showed that a 5 mmol·L^(−1) Cr^(6+)solution significantly inhibited seed germination(P<0.05).DA-6 at 40~60 mmol·L^(−1) significantly increased the germination index of white clover under chromium stress(P<0.05),and the greatest effect was achieved at a concentration of 60 mmol·L^(−1).Moreover,free proline and soluble sugar increased by 1.6 and 3.8 times,respectively,and cell osmotic potential was significantly decreased by 178%for seeds soaked in DA-6 during germination under Cr^(6+)stress(P<0.05).The antioxidant enzyme activity and key enzymes involved in the ascorbate-glutathione metabolism cycle of seeds soaked in DA-6 significantly increased(P<0.05),thereby reducing oxidative damage and improving cell membrane stability during germination under Cr^(6+)stress.These results indicate that DA-6 significantly improves the seed germination rate and Cr^(6+)tolerance of white clover during germination and early development,which are closely associated with enhancement of osmotic adjustment and improvement of antioxidant defense.