外源γ-氨基丁酸对低氧胁迫下甜瓜幼苗活性氧代谢的影响  

Exogenous γ-Aminobutyric Acid Affects Reactive Oxygen Species Metabolism of Melon Seedlings under Hypoxia Stress

作　　者：杨丽文[1] 高洪波[1] 吴晓蕾[1] 宫彬彬[1] 

机构地区：[1]河北农业大学园艺学院,河北保定071001

出　　处：《西北植物学报》2011年第11期2243-2251,共9页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家自然科学基金(30900994)

摘　　要：以甜瓜品种‘西域一号’幼苗为材料,采用营养液水培方法,设置正常通气(对照)、正常通气+GABA(5mmol.L-1)、低氧胁迫、低氧胁迫+GABA(5mmol.L-1)4个处理,研究了外源γ-氨基丁酸(GABA)对正常通气和低氧胁迫下甜瓜幼苗活性氧代谢的影响。结果表明:与正常通气处理相比,低氧胁迫处理导致甜瓜幼苗体内O2.-产生速率和H2O2、MDA含量显著增加,同时SOD、POD、CAT、APX、GR等抗氧化酶活性和抗氧化物质AsA、GSH含量显著提高。低氧胁迫下外源GABA能显著提高甜瓜幼苗叶片SOD、CAT、APX、GR等酶活性和AsA、GSH含量,降低了植株体内O2.-产生速率和H2O2、MDA含量;而正常通气条件下添加外源GABA处理对甜瓜幼苗活性氧代谢的影响较小,仅CAT、GR活性和AsA、GSH含量显著提高,而H2O2、MDA含量显著降低。结果证明,添加外源GABA可以通过显著提高低氧胁迫下抗氧化酶活性和抗氧化物质含量来降低甜瓜幼苗活性氧积累,维持其细胞膜结构稳定性,从而有效减轻低氧胁迫对甜瓜幼苗的伤害。This paper investigated the effects of exogenous γ-aminobutyric acid（GABA） on reactive oxygen species（ROS） metabolism of melon seedlings ＇Xiyu 1＇ under normoxia and hypoxia stress with hydroponics culture.Seedlings were cultured under normoxia＋GABA（5 mmol·L-1）,hypoxia stress,hypoxia stress＋GABA（5 mmol·L-1） respectively for 0,2,4,6,8 d,and with normoxia treatment as the control.The results showed that the productive rate of O-·2,contents of H2O2 and MDA in roots and leaves were significantly increased when melon seedlings were grown in the nutrient solution under hypoxia stress.Meanwhile,the activities of SOD,POD,CAT,APX,GR and the contents of AsA,GSH were increased compared with control.Exogenous GABA application under hypoxia stress could significantly decreased the productive rate of O-·2,the contents of H2O2 and MDA of melon seedlings by increasing the activities of SOD,CAT,APX,GR and the contents of AsA,GSH.However,exogenous GABA application had less effect on ROS metabolism under normoxia condition,including significantly improved the activities of CAT,GR and the contents of AsA,GSH,significantly decreased the contents of H2O2 and MDA,but had little influence on other physiological indexes.The results suggested that exogenous GABA alleviated the harm of hypoxia stress in melon,most likely by decreasing ROS accumulation and maintaining the stability of cell membrane structure through significantly increasing antioxidant enzyme activities and antioxidant substance contents in roots and leaves of melon seedlings.

关 键 词：低氧胁迫 Γ-氨基丁酸 甜瓜 活性氧代谢 

分 类 号：Q945.78[生物学—植物学]