PDF(Pubmed)
Abstract：
Heavy metal pollution is one of the major agronomic challenges. Tungsten (W) exposure leads to its accumulation in plants, which in turn reduces plant growth, inhibits photosynthesis and induces oxidative damage. In addition, the predicted increase in CO2 could boost plant growth under both optimal and heavy metal stress conditions. The aim of the present study was to investigate the effect of W on growth, photosynthetic parameters, oxidative stress and redox status in rye plants under ambient and elevated (eCO2) levels. To this end, rye plants were grown under the following conditions: ambient CO2 (aCO2, 420 ppm), elevated CO2 (eCO2, 720 ppm), W stress (350 mg kg-1 soil) and W+eCO2. W stress induced significant (p < 0.05) decreases in growth and photosynthesis, increases in oxidative damages (lipid peroxidation) and the antioxidant defense system, i.e., ascorbate (ASC), reduced glutathione (GSH), GSH reductase (GR), peroxidase (POX), catalase (CAT), superoxide dismutase (SOD), ASC peroxide (APX) and dehydroascorbate reductase (DHAR). On the other hand, eCO2 decreased W uptake and improved photosynthesis, which sequentially improved plant growth. The obtained results showed that eCO2 can decrease the phytotoxicity risks of W in rye plants. This positive impact of eCO2 on reducing the negative effects of soil W was related to their ability to enhance plant photosynthesis, which in turn provided energy and a carbon source for scavenging the reactive oxygen species (ROS) accumulation caused by soil W stress.
摘要：
重金属污染是主要的农艺挑战之一。钨（W）暴露导致其在植物中的积累，这反过来又降低了植物的生长，抑制光合作用并诱导氧化损伤。此外,在最佳和重金属胁迫条件下，预测的CO2增加可以促进植物生长。本研究的目的是研究W对生长的影响，光合参数，在环境和升高的（eCO2）水平下，黑麦植物的氧化应激和氧化还原状态。为此,黑麦植物在以下条件下生长：环境CO2（aCO2，420ppm），CO2升高（eCO2，720ppm），W胁迫(350mgkg-1土壤)和W+eCO2。W胁迫显著(p<0.05)降低生长和光合作用,氧化损伤（脂质过氧化）和抗氧化防御系统的增加，即，抗坏血酸（ASC），还原型谷胱甘肽（GSH），GSH还原酶(GR),过氧化物酶(POX),过氧化氢酶(CAT),超氧化物歧化酶（SOD），ASC过氧化物(APX)和脱氢抗坏血酸还原酶(DHAR)。另一方面,eCO2降低了W的吸收，改善了光合作用，依次改善了植物生长。结果表明，eCO2可以降低黑麦植物中W的植物毒性风险。eCO2对减少土壤W的负面影响的积极影响与其增强植物光合作用的能力有关，反过来又提供了能量和碳源，以清除土壤W胁迫引起的活性氧（ROS）积累。
