再生水灌溉对小麦抗氧化酶基因表达的影响

Effects of Reclaimed Water Irrigation on Antioxidant Enzyme Gene Expression in Wheat

再生水用于灌溉能够有效缓解水资源紧张的压力,而再生水中重金属富集等环境条件对植物生长而言是逆境。植物在逆境中生长会产生过量的活性氧(ROS)如过氧化氢(H2O2),会对植物造成损伤。抗坏血酸过氧化物酶(APX)作为一种关键的抗氧化酶类,以抗坏血酸(AsA)为底物,能够将H2O2转化为H2O,从而调节ROS含量,这一过程与NADP/NADPH和GSH/GSSG这2个氧化还原对相偶联。试验以冬小麦为研究对象,对清水、再生水以及二者交替灌溉下的小麦根部抗氧化酶基因表达变化进行分析。结果表明,再生水灌溉下小麦根部H2O2含量比清水灌溉低,APX和SOD基因表达均增强,并且在再生水灌溉下,APX基因表达量在灌浆期高于收获期;与NADP/NADPH氧化还原过程相比,以GSH为底物生成AsA的过程对再生水灌溉条件的响应更强。研究结果可为再生水灌溉研究与应用提供科学依据。

Reclaimed water irrigation can alleviate the pressure of water shortage effectively,but it seems to be a stress environment condition for plant growth in reclaimed water such as heavy metal enrichment.Plants produce excessive reactive oxygen species(ROS)in stress,such as hydrogen peroxide(H2O2),which can cause damage to plants.Ascorbic acid peroxidase(APX),a significant antioxidant enzymes,can regulate the ROS content by catalyzing the reduction of H2O2 to H2O with ascorbic acid(AsA)as the substrate.This process is coupled with NADP/NADPH and GSH/GSSG redox reaction.This study analyzed antioxidant enzyme gene expression of winter wheat root under the condition of fresh water,reclaimed water and alternating irrigation.The results showed that H2O2 content decreased and expression level of APX and SOD genes increased in wheat root under reclaimed water irrigation,compared with fresh water.APX gene expression arised more in filling period than harvest period under reclaimed water irrigation.Compared with NADP/NADPH reaction,the generating of AsA as GSH substrate was more sensitive to the reclaimed water irrigation.These data will provide scientific basis for the research and application of reclaimed water irrigation.