Simultaneous overexpression of both CuZn superoxide dismutase and ascorbate peroxidase in transgenic tall fescue plants confers increased tolerance to a wide range of abiotic stresses
Simultaneous overexpression of both CuZn superoxide dismutase and ascorbate peroxidase in transgenic tall fescue plants confers increased tolerance to a wide range of abiotic stresses
复制标题
DOI：
10.1016/j.jplph.2007.01.003
复制
发表时间：
2007-12-01
影响因子：
4.3
通讯作者：
Lee, Byung-Hyun
中科院分区：
文献类型：
--
作者：
Lee, Sang-Hoon;Ahsan, Nagib;Lee, Byung-Hyun
为了减轻生物或非生物胁迫造成的氧化损伤，植物进化出复杂的抗氧化防御机制，包括诱导抗氧化和抗氧化酶，如超氧化物歧化酶（SOD）和抗坏血酸过氧化物酶（APX）。为了确定是否过表达的基因编码的铜锌SOD（CuZnSOD）和APX在植物中能够减少活性氧（ROS）在响应非生物胁迫产生的，我们产生了转基因高羊茅植物表达的CuZnSOD和APX基因在叶绿体的氧化胁迫诱导型启动子，甘薯过氧化物酶阴离子2（SWPA2）的控制下。通过农杆菌介导的遗传转化获得转基因植株，并通过DNA印迹分析确认基因型。转基因植物暴露于几个ROS产生的非生物胁迫，如甲基紫精（MV），过氧化氢，和重金属铜，镉，砷，和它们的耐受性进行了评估。高水平的CuZnSOD和APX基因的转录本在这些处理下的转基因植物表明，转基因的功能表达。与转基因植物相比，暴露于非生物胁迫的对照植物的叶片中产生更高量的ROS，导致硫代巴比妥酸反应物质（TBARS）增加，离子泄漏和叶绿素降解。这些参数在转基因植物中显着较低。酶活性测定和非变性聚丙烯酰胺凝胶电泳（PAGE）结果表明，在非生物胁迫下，转基因植株中总SOD和APX活性较高。我们的结论是，在转基因高羊茅植物的抗氧化防御增加的机制之一是过表达的CuZnSOD和APX基因，这是利用清除ROS，从而提供了改善的耐受性非生物胁迫。(C)2007年，Elsevier GmbH。All rights reserved.
To mitigate the oxidative damage inflicted by biotic or abiotic stresses, plants have evolved complex anti-oxidative defense mechanisms that involve induction of antioxidant and anti-oxidative enzymes, such as superoxide dismutase (SOD) and ascorbate peroxidase (APX). To determine whether overexpression of the genes encoding copper-zinc SOD (CuZnSOD) and APX in plants is capable of decreasing reactive oxygen species (ROS) produced in response to abiotic stresses, we generated transgenic tall fescue plants expressing the CuZnSOD and APX genes in chloroplasts under the control of the oxidative stress-inducible promoter, sweet potato peroxidase anionic 2 (SWPA2). Transgenic plants were generated by Agrobacterium-mediated genetic transformation, and genotypes were confirmed by DNA blot analysis. Transgenic plants were exposed to several ROS-generating abiotic stresses, such as methyl viologen (MV), H2O2, and the heavy metals copper, cadmium, and arsenic, and their tolerance was evaluated. High levels of CuZnSOD and APX gene transcripts in the transgenic plants under these treatments suggested that the transgenes were functionally expressed. Compared to transgenic plants, higher amounts of ROS were generated in the leaves of control plants exposed to abiotic stresses, resulting in increased thiobarbituric acid reactive substances (TBARS), ion Leakage, and chlorophyll degradation. These parameters were significantly lower in transgenic plants. Enzyme activity assays and native polyacrylamide get electrophoresis (PAGE) showed that total SOD and APX were highly active in transgenic plants under the abiotic stresses examined. We conclude that one of the mechanisms of increased anti-oxidative defense in transgenic tall fescue plants is overexpression of the CuZnSOD and APX genes, which are utilized in scavenging ROS and thus provide improved tolerance to abiotic stresses. (C) 2007 Elsevier GmbH. All rights reserved.