UV-B辐射对两种高山植物抗氧化酶影响及叶绿素荧光的响应

NWIPB OpenIR

	UV-B辐射对两种高山植物抗氧化酶影响及叶绿素荧光的响应
其他题名	The influence of antioxidant enzyme and the response of chlorophyll fluorescence in two alpine species
	李和平
学位类型	硕士
导师	师生波
	2008-06-04
学位授予单位	中国科学院西北高原生物研究所
学位授予地点	西北高原生物研究所
关键词	Uv-b辐射高山植物抗氧化酶叶绿素荧光适应性
摘要	全球变化中平流层中臭氧的损耗所导致的达地球表面UV-B辐射的明显增加已经是一个引起各国政府和科学家密切关注的重要方面。美国NASA卫星总臭氧图谱(TOMS)的观测表明，青藏高原上空已出现了大面积臭氧极低值区域，更多研究也表明青藏高原是永久UV高值区之一。本研究以青藏高原高寒草甸主要伴随物种麻花艽和美丽风毛菊为实验材料，在中国科学院海北高寒草甸生态系统定位站进行了两种UV-B辐射的实验，模拟臭氧衰竭5%的长期UV-B增强辐射和降低自然辐射的短期UV-B滤过实验。此两种实验方法相互补充，相互验证，同时探讨了麻花艽和美丽风毛菊在高海拔高辐射地区对UV-B辐射的生理生态响应。 (1)两种实验中，高UV-B辐射强度并未引起麻花艽光合色素的明显变化，紫外吸收物质含量有所下降；抗氧化酶SOD，POD，CAT活性都有下降趋势；Fv/Fm ，Fv′/Fm′ ，PSII升高。美丽风毛菊在高UV-B处理下光合色素有所升高，紫外吸收物质含量均未有明显的变化；SOD活性有所升高；UV-B处理一定时间后Fv/Fm，Fv′/Fm′，PSII均有升高。说明两高山植物在长期UV-B辐射和短期UV-B滤过实验下光合色素，紫外吸收物质含量以及抗氧化性酶和叶绿素荧光参数的变化趋势具有一致性。实验验证了两种实验设计的可行性，实验方法的可靠性。 (2)长期UV-B增强辐射和短期UV-B滤过实验的结果都表明，麻花艽和美丽风毛菊已经适应了强UV-B辐射的环境，一定范围内人为的改变它们所接受的UV-B辐射强度对它们不会造成很大程度上的影响。 (3)本实验和以前的结果都表明，麻花艽和美丽风毛菊对UV-B辐射强度改变的适应方式不尽相同，具体表现为美丽风毛菊能积极抵御强UV-B辐射，而麻花艽则消极忍耐。UV-B辐射下，麻花艽叶片的光合色素没有变化，抗氧化酶的活性有所降低，但反映光系统II光化学效率的3个参数都有所升高，说明尽管UV-B辐射具有潜在的伤害效应，但并没有对光系统II构成威胁；美丽风毛菊在UV-B处理后能提高光合色素含量、增加体内抗氧化酶的活性来积极抵御UV-B辐射的影响，因此反映光系统II光化学效率的3个参数都较高。
其他摘要	Ozone exhausting in the stratosphere could result in enhancement of UV-B intensity at the earth’s surface, which have already been aroused attention to the government and scientists.The data from TOMS of NASA indicated that there was large-scale depression of ozone column in the Qinghai-tibet Plateau. Qinghai-tibet Plateau is one of the permanent high-value UV radiaction district in the world. As material in this study, Gentiana straminea Maxim and Saussurea superba Anthony are the main complemental species in alpine Kobresia meadow. The influence of antioxidant enzyme activity and the response of chlorophyll fluorescence parameters in these two alpine plants were the mainly studied problem in this study. The experiment included two parts, the long-term enhanced and short-term filtered UV-B treatment. Field experiments were conducted in alpine meadow at the Haibei Alpine Meadow Ecosystem Reserch Station. The main result from this study as follow: (1) The results from long-term enhanced UV-B radiation were consisted with the results from short-term filtered UV-B radiation. The change trends of contents of photopigment and UV-B absorbing compounds, antioxidant enzyme activity and chlorophyll fluorescence parameters were similar in long-term enhanced and short-term filtered UV-B radiation experiments in both alpine plants of G. straminea and S. superba. (2) The G. straminea and S. superba have already adapted to the stronger UV-B radiation environment. There were no significant influences in two alpine species under artificial UV-B environment. (3) There are differents styles to adapt the stronger UV-B radiation environment in two alpine plants. There was no threatening to PSII under enhanced UV-B intensity in G. straminea. The contents of photopigment and activity of antioxidant enzyme were inproved in S. superba, which were used to resist the damage from enhanced UV-B intensity.
页数	54
语种	中文
文献类型	学位论文
条目标识符	http://210.75.249.4/handle/363003/3196
专题	中国科学院西北高原生物研究所
推荐引用方式 GB/T 7714	李和平. UV-B辐射对两种高山植物抗氧化酶影响及叶绿素荧光的响应[D]. 西北高原生物研究所. 中国科学院西北高原生物研究所,2008.

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