外源γ-氨基丁酸调控甜瓜叶绿体活性氧代谢应对短期盐碱胁迫  

Response of reactive oxygen metabolism in melon chloroplasts to short-term salinity-alkalinity stress regulated by exogenous γ-aminobutyric acid

作　　者：向丽霞[1,2,3] 胡立盼[1,2,3] 胡晓辉[1,2,3] 潘雄波 任文奇[1,2,3] 

机构地区：[1]西北农林科技大学园艺学院,陕西杨凌712100 [2]农业部西北设施园艺工程重点实验室,陕西杨凌712100 [3]陕西省设施农业工程中心,陕西杨凌712100

出　　处：《应用生态学报》2015年第12期3746-3752,共7页Chinese Journal of Applied Ecology

基　　金：国家"十二五"科技支撑计划项目(2014BAD14B06);陕西省科技攻关项目(2015NY102);杨凌示范区科技计划项目(2014NY-17)资助

摘　　要：以甜瓜品种‘金辉1号'为试材,采用深液流水培法,研究外源γ-氨基丁酸(GABA)对短期盐碱胁迫下甜瓜幼苗叶绿体活性氧代谢的调控作用.结果表明:盐碱胁迫显著提高了甜瓜叶绿体内光合色素、丙二醛(MDA)和过氧化氢(H_2O_2)含量及超氧阴离子(O_2~·)产生速率;增加抗坏血酸(AsA)和谷胱甘肽(GSH)等抗氧化物质含量;明显抑制H^+-ATP酶(H^+-ATPase)和H^+-焦磷酸酶(H^+-PPiase)活性.外源叶面喷施GABA有效抑制了盐碱胁迫引起的叶绿体内O_2、H_2O_2和MDA的积累缓解了光合色素增加的趋势;显著提高SOD和AsA-GSH循环各个酶的活性,增加了AsA和GSH库,降低了AsA/DHA和GSH/GSSH比值,增强了H^+-ATPase和H^+-PPiase活性.表明外源GABA能加快叶绿体内活性氧代谢,促进AsA-GSH循环的运转,维持细胞膜的渗透性,进而缓解了盐碱胁迫引起的氧化伤害.The regulatory effect of exogenous γ-aminobutyric acid（GABA） on metabolism of reactive oxygen species（ROS） in melon chloroplasts under short-term salinity-alkalinity stress were investigated in melon variety ＇Jinhui No.1＇,which was cultured with deep flow hydroponics.The result showed that under salinity-alkalinity stress,the photosynthetic pigment content,MDA content,superoxide anion（O2^·） production rate and hydrogen peroxide（H2O2） content in chloroplast increased significantly,the contents of antioxidants ascorbic acid（AsA） and glutathione（GSH） increased,and the activities of H-ATPase and H^＋-PPiase were inhibited obviously.With exogenous GABA application,the accumulations of O2^·,MDA and H2O2 induced by salinity-alkalinity stress were inhibited.Exogenous GABA alleviated the increase of photosynthetic pigment content,improved the activity of SOD,enzymes of AsA-GSH cycle,total AsA and total GSH while decreased the AsA/DHA ratio and GSH/GSSH ratio.Foliar GABA could enhance the H^＋-ATPase and H^＋-PPiase activities.Our results suggested that the exogenous GABA could accelerate the ROS metabolism in chloroplast,promote the recycle of AsA-GSH,and maintain the permeability of cell membrane to improve the ability of melon chloroplast against salinity-alkalinity stress.

关 键 词：GABA 甜瓜 叶绿体 抗氧化 As A-GSH循环 

分 类 号：S652[农业科学—果树学]