外源γ-氨基丁酸对营养液低氧胁迫下网纹甜瓜幼苗抗氧化酶活性和活性氧含量的影响

Effects of Exogenous y-Aminobutyric Acid on Antioxidant Enzyme Activity and Reactive Oxygen Content in Muskmelon Seedlings Under Nutrient Solution Hy-poxia Stress

在营养液低氧胁迫处理下,研究了γ-氨基丁酸(GABA)处理对低氧敏感性不同的网纹甜瓜品种植株根和叶抗氧化酶活性和活性氧(ROS)含量的影响。结果表明:在低氧胁迫下,GABA处理提高了网纹甜瓜植株根和叶抗氧化酶SOD、POD、CAT活性,降低了H2O2、O2、MDA等ROS含量,其中GABA 50mmnol／L处理效果显著高于GABA 25和100 mmol／L的处理;与耐低氧性弱的"西域一号"品种相比,GABA处理对耐低氧性强的"东方星光"品种效果更明显,表明外源GABA处理通过促进抗氧化酶活性的提高,降低了低氧胁迫下植株体内ROS含量,增强植株的耐低氧的能力。

The effects of exogenous y-aminobutyric acid (GABA) on antioxidant defense system and reactive oxygen species (ROS) in seedlings of two varieties with different resistance to hypoxia stress were studied under hy-poxia stress in a nutrient solution culture system. The results showed that GABA treatments enhanced the activities of antioxidant enzyme including SOD(Fig.l), POD(Fig.2), CAT (Fig.3), while the concentrations of H2O2 (Fig.4), O2(Fig. 5), MDA(Fig.6) decreased under hypoxia stress. Among the treatments of three different GABA concentrations, the effect of 50 mmol/L GABA treatment was better than that of 25 mmol/L GABA and 100 mmol/L GABA treatments. The effect of treatment with GABA in 'Dongfang xingguang' seedlings, which had stronger hy-poxia-resistance to hypoxia stress were better than that in 'Xiyu No.1' seedlings which had lower hypoxia-resistance. It indicate that GABA treatment of exogenous spraying to leaves can increase the activities of antioxidant enzyme under the hypoxia stress and plays an important role in enhancing the resistance to hypoxia stress of muskmelon seedlings through keeping low ROS contents.