Marabottini R, Schraml C, Paolacci A R, Sorgona A, Raschi A, Rennenberg H, Badiani M
Dipartimento di Agrobiologia e Agrochimica, Universita' di Viterbo, Italy.
Environ Pollut. 2001;115(3):413-23. doi: 10.1016/s0269-7491(01)00231-7.
Foliar antioxidants were measured in adult individuals of holm oak (Quercus ilex L.) and white oak (Q. pubescens Willd.) growing in the field either within the vicinity of natural CO2 springs or at a nearby control site under ambient CO2, which had been previously exposed to either daily irrigation or no irrigation. In oak trees permanently exposed to elevated CO2 the activities of antioxidant enzymes tended to be lower and the ascorbate pool was larger and more in reduced form, suggesting an attenuation of the oxidative risk in the CO2-enriched trees. In the enriched individuals of both species. the imposition of water shortage significantly increased the size of the glutathione pool and the total superoxide dismutase activity in a species-specific manner. Moreover, water-stressed trees exposed to elevated CO2 tended to have higher catalase and ascorbate peroxidase activities than water-stressed control trees. Such changes may reflect the need for an enhanced compensatory effort when trees acclimated to elevated CO2 are exposed to oxidative stress-promoting environmental factors, such as water shortage.
在野外生长的成年圣栎（Quercus ilex L.）和柔毛栎（Q. pubescens Willd.）个体中测量了叶片抗氧化剂，这些橡树要么生长在天然二氧化碳泉附近，要么生长在附近环境二氧化碳浓度下的对照地点，且之前分别接受每日灌溉或不灌溉处理。在长期暴露于高浓度二氧化碳的橡树中，抗氧化酶的活性往往较低，抗坏血酸库更大且更多呈还原形式，这表明在二氧化碳浓度升高的树木中氧化风险有所降低。在这两个物种暴露于高浓度二氧化碳的个体中，缺水显著增加了谷胱甘肽库的大小和总超氧化物歧化酶活性，且具有物种特异性。此外，暴露于高浓度二氧化碳的水分胁迫树木往往比水分胁迫的对照树木具有更高的过氧化氢酶和抗坏血酸过氧化物酶活性。当适应高浓度二氧化碳的树木暴露于促进氧化应激的环境因素（如缺水）时，这些变化可能反映了增强补偿作用的必要性。
