Brunschön-Harti S, Fangmeier A, Jäger H J
Institute for Plant Ecology, University of Giessen, Heinrich-Buff-Ring 38, D-35392 Giessen, Germany.
Environ Pollut. 1995;90(1):95-103. doi: 10.1016/0269-7491(94)00084-q.
To study the biochemical mechanism of EDU protection against ozone injury, peroxidase, ascorbate-dependent peroxidase, and catalase activities, and the contents of ascorbic acid, dehydroascorbic acid, malondialdehyde and soluble protein were measured in Phaseolus vulgaris L. cv. Lit exposed to ozone and ethylenediurea (EDU) in open-top chambers. Plants not treated with EDU showed foliar bronzing due to ozone, while EDU-treated plants were not affected. EDU application modified the reaction of biochemical parameters to ozone. Soluble protein content was elevated by EDU. Peroxidase activity increased with ozone exposure in untreated plants only, while ascorbate-dependent peroxidase activity was lower in EDU treated plants. Catalase activity decreased in EDU-untreated plants. The ratio of ascorbic acid to dehydroascorbic acid was significantly increased in EDU treated plants. These results suggest that EDU might induce ascorbic acid synthesis and therefore provide the plant with a very potent antioxidant. Or the content of hydrogen peroxide was reduced due to other unknown processes and caused a delay in foliar senescence, regardless of whether these processes were ozone-induced or due to natural aging processes.
为研究乙二脲（EDU）对臭氧伤害的保护作用的生化机制，在开顶式气室中，对暴露于臭氧和乙二脲（EDU）环境下的普通菜豆品种利特（Phaseolus vulgaris L. cv. Lit）测定了过氧化物酶、抗坏血酸依赖性过氧化物酶和过氧化氢酶的活性，以及抗坏血酸、脱氢抗坏血酸、丙二醛和可溶性蛋白的含量。未用EDU处理的植株因臭氧作用出现叶片发黄现象，而用EDU处理的植株未受影响。EDU的施用改变了生化参数对臭氧的反应。EDU提高了可溶性蛋白含量。仅在未处理的植株中，过氧化物酶活性随臭氧暴露而增加，而在EDU处理的植株中，抗坏血酸依赖性过氧化物酶活性较低。在未用EDU处理的植株中过氧化氢酶活性降低。在EDU处理的植株中，抗坏血酸与脱氢抗坏血酸的比值显著增加。这些结果表明，EDU可能诱导抗坏血酸的合成，从而为植物提供一种非常有效的抗氧化剂。或者，由于其他未知过程，过氧化氢含量降低，导致叶片衰老延迟，无论这些过程是由臭氧诱导还是自然衰老过程引起的。
