γ-氨基丁酸浸种对低氧胁迫下甜瓜种子萌发及芽苗生长和活性氧代谢的影响

以甜瓜(Cucumis melo L.)为材料,研究了不同浓度γ-氨基丁酸(GABA)浸种处理对低氧胁迫下种子萌发及芽苗生长和活性氧代谢的影响。结果表明:低氧胁迫下,种子的发芽率、发芽势显著降低,芽苗的胚根长、胚轴长和抗氧化酶(SOD、POD和CAT)的活性显著降低,芽苗的O2.-产生速率和H2O2含量显著增加;而不同浓度GABA均能提高低氧胁迫下发芽率、发芽势和芽苗的胚根长、胚轴长、抗氧化酶活性,而芽苗的O2.-产生速率和H2O2含量显著降低。研究表明,GABA浸种处理能促进低氧胁迫下甜瓜种子的萌发,并通过活性氧代谢的调节缓解低氧胁迫造成的伤害,其中以GABA浓度2～2.5mmol/L处理效果最好。

Effect of seed soaking with γ-aminobutyric acid on seed germination and bud seedling growth and reactive oxygen species metabolism of melon under hypoxia stress

Melon seeds were used as experimental materials,and the effects of γ-aminobutyric acid(GABA)at different concentrations on seed germination,bud seedling growth and reactive oxygen metabolism of melon under hypoxia stress were studied.The results showed that hypoxia stress significantly inhibited seed germination and bud seedling growth of the plant,including the decreased germination rate,germination energy,radicle and hypocotyl length,activities of antioxidative enzymes and the O·-2 increased productive rate and H2O2 content.Different concentrations of GABA were found increased the germination rate,germination energy,radicle and hypocotyl length,and the activities of antioxidative enzymes,while significantly decreased the O·-2productive rate and H2O2 content.The result also showed that exogenous GABA alleviated the hypoxia harm to melon seeds,and the best result was achieved by the treatment with GABA at the concentration of 2-2.5 mmol/L.