NaCl胁迫下外源亚精胺对发芽大豆生理生化及γ-氨基丁酸代谢的影响

Exogenous spermidine regulating the main physiological and the GABA accumulation in germinating soybean under NaCl stress

在NaCl胁迫下,于大豆发芽期间添加亚精胺(Spd),探究其对常规发芽大豆生理生化指标的影响,并检测γ-氨基丁酸(GABA)含量及其合成关键酶活性的变化。结果表明:添加外源Spd可显著缓解NaCl对发芽大豆生长抑制效应,相对于单独NaCl处理,联合Spd处理2、4 d时发芽大豆芽长分别增加22%和25%, GABA含量分别增加16%和92%。与对照相比, NaCl处理及其联合Spd处理发芽大豆中GABA合成关键酶活性均显著提高,从而促进GABA富集。添加氨基胍后,经NaCl、Spd和NaCl+Spd处理4 d时发芽大豆中GABA支路贡献分别占GABA总量的19.4%、42.7%和44.0%,发芽大豆经Spd处理其GABA支路途径对GABA积累的贡献率增加。

In this paper, the effects of adding spermidine(Spd) on the physiological and biochemical indexes of soybean under NaCl stress during germination were studied, and the changes of γ-aminobutyric acid(GABA) content and the activity of its key enzyme were detected. Results showed that the application of Spd significantly alleviated the negative effect of NaCl stress on germinating soybeans. Compared with the NaCl treatment, the sprout length in two-day and four-day germinating soybeans under Spd+NaCl treatment increased by 22% and 25%, and GABA content increased by 16% and 92%, respectively. NaCl, Spd and NaCl+Spd treatments significantly increased GABA key synthase activities during germination compared with the control(P<0.05). Moreover, after added the aminoguanidine, in two-day and four-day germinating soybeans, the contribution rate of GABA shunt under NaCl, Spd, NaCl+Spd treatments were 19.4%, 42.7% and 44.0%, respectively.