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.