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温度通常被认为是植物生长和生产的重要限制因子,全球变暖严重影响生态系统,但全球变暖对亚热带杉木(Cunninghamia lanceolata)叶片膜脂过氧化及保护酶活性的影响并不甚清楚。该研究在野外利用电缆对土壤增温,设置对照和增温2种处理,每个处理5个重复。通过测定渗透调节物质、内在水分利用效率、保护酶活性及丙二醛等指标,探究增温对杉木生理生化特征的影响。研究表明:1)增温提高渗透调节能力,但对杉木叶片膜脂过氧化作用不明显;2)增温显著提高杉木的水分利用效率和固碳效益,即降低了固碳耗水成本;3)增温降低超氧化物歧化酶活性和过氧化物酶活性,却显著提高过氧化氢酶活性和抗坏血酸过氧化酶活性。由此可见,杉木主要通过提高保护酶(特别是过氧化氢酶和抗坏血酸过氧化酶)活性以减轻高温胁迫伤害,这有助于维持杉木细胞代谢稳定。因此,该区域在未来全球变化背景下的温度升高效应值得长期而深入的探讨。
Temperature is generally considered to be an important limiting factor for plant growth and production. Global warming severely affects ecosystems, but the effects of global warming on membrane lipid peroxidation and protective enzyme activity in leaves of Cunninghamia lanceolata are not well understood. In this study, the soil was warmed by electric cables in the field. Two treatments were set up for comparison and temperature increase, with five replicates per treatment. The effects of increasing temperature on the physiological and biochemical characteristics of Chinese fir were investigated by measuring osmotic adjustment material, intrinsic water use efficiency, protective enzyme activity and malondialdehyde (MDA). The results showed that: 1) warming increased the ability of osmotic adjustment, but had no obvious effect on membrane lipid peroxidation of Chinese fir leaf; 2) warming significantly increased the water use efficiency and carbon sequestration benefits of Chinese fir, which reduced the cost of carbon sequestration; 3 ) Warming decreased superoxide dismutase activity and peroxidase activity, but significantly increased catalase activity and ascorbate peroxidase activity. Thus, Cunninghamia lanceolata mainly helps to maintain the metabolic stability of Cunninghamia lanceolata cells by increasing the activity of protective enzymes (especially catalase and ascorbate peroxidase) to reduce the damage caused by high temperature stress. Therefore, the temperature rise effect of the region in the context of future global changes merits a long-term and in-depth discussion.