碱胁迫下内生真菌共生对布顿大麦抗氧化酶和ASA-GSH循环的影响

Effects of Endophytic Fungi on Antioxidant Enzyme Activity and ASA-GSH Circulation of Hordeum bogdanii under Alkali Stress

内生真菌能够提高宿主植物的抗逆性,而碱胁迫使植物体内积累大量的活性氧,加速植物衰老和死亡。为探究碱胁迫下内生真菌对宿主布顿大麦抗氧化酶和抗坏血酸-谷胱甘肽(ASA-GSH)循环系统的影响,本试验以带内生真菌(E+)和不带内生真菌(E-)的布顿大麦为材料,设置0、25、50、100、150、200 mmol/L混合碱(Na_(2)CO_(3)+NaHCO_(3))胁迫处理,研究碱胁迫下内生真菌对布顿大麦过氧化物酶(POD)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)活性及叶片ASA-GSH循环中抗坏血酸过氧化物酶(APX)、谷胱甘肽还原酶(GR)、谷胱甘肽过氧化物酶(GPX)活性和谷胱甘肽(GSH)含量变化的影响。结果表明,在碱胁迫下,抗氧化酶和ASA-GSH循环系统均受内生真菌影响,E+布顿大麦中的POD和GR活性低于E-布顿大麦,而CAT、SOD和APX活性及GSH含量显著高于E-布顿大麦;低浓度碱胁迫下,E+布顿大麦叶片的GPX活性高于E-布顿大麦,但当碱浓度大于100 mmol/L时,则表现为E-高于E+。说明碱胁迫下内生真菌能够提高布顿大麦的抗氧化性,改变ASA-GSH循环,增强植株的抗逆性。本研究结果可为合理利用内生真菌进行布顿大麦抗逆新种质创新和新品种选育提供理论基础。

Endophytic fungi can improve stress resistance of host plants,while alkali stress causes accu-mulation of large amount of reactive oxygen species,accelerating plant senescence and death.In order to in-vestigate the effects of endophytic fungi on antioxidant enzymes and ascorbic acid-glutathione(ASA-GSH)cir-culatory system of host Hordeum bogdanii under alkali stress,H.bogdanii plants with(E+)or without(E-)endophytic fungi were subjected to mixed alkali(Na_(2)CO_(3)+NaHCO_(3))stress of 0,25,50,100,150 and 200 mmol/L mixed alkali to study the changes of peroxidase(POD),catalase(CAT),superoxide dismutase(SOD)activities,and ascorbic acid peroxidase(APX),glutathione reductase(GR),glutathione peroxidase(GPX)activities and glutathione(GSH)content in leaf ASA-GSH cycle of H.bogdanii.The results showed that under alkali stress,the antioxidant enzymes and ASA-GSH circulatory system were both affected by endo-phytic fungi.The activities of POD and GR in E+H.bogdanii plants were lower than those in E-ones,while the activities of CAT,SOD,APX and GSH content were significantly higher in E+plants than those in Eones.The GPX activity in E+plants was higher than that in E-ones under low-concentration alkali stress,but was lower when the alkali concentration was greater than 100 mmol/L.The research results indicate that endo-phytic fungi could enhance the antioxidant capacity of H.bogdanii under alkali stress,alter the ASA-GSH cir-culation,and enhance plant stress resistance,which could provide a heoretical basis for reasonably utilizing endophytic fungi to breed new variety of H.bogdanii with resistance to stresses.