%0 Journal Article
%T Responses of PSII photochemistry efficiency and photosynthetic pigments of Saussurea superba to short-term UV-B-supplementation<br>高山植物美丽风毛菊PSII光化学效率和光合色素对短期增补UV-B辐射的响应
%A SHI Sheng-Bo
%A SHANG Yan-Xia
%A SHI Rui
%A ZHANG Bo
%A <br>师生波
%A 尚艳霞
%A 师瑞
%A 张波
%J 植物生态学报
%D 2012
%I Editorial Office of Chinese Journal of Plant Ecology
%X Aims Native alpine plants that have grown and evolved on the Qinghai-Tibetan Plateau of China for a long time have developed a strong adaptation capacity for harsh environmental factors,such as low temperature,low air pressure,strong sunlight and solar UV-B radiation.The objective of this study was to determine the response of PSII photochemistry efficiency to short-term enhanced solar UV-B intensity in alpine plants.We examined whether UV-B-absorbing compounds were sufficiently efficient to protect the photosynthetic apparatus from UV-B photo-inactivation or photo-damage and evaluated the influence of UV-B radiation on photosynthetic pigments.Methods Field experiments were conducted during the 2008 and 2009 growing seasons in alpine Kobresia humilis meadow near Haibei Alpine Meadow Ecosystem Research Station(37°29’-37°45’ N,101°12’-101°33’ E;alt.3 200 m) using the native alpine plant Saussurea superba.Short-term UV-B-supplementation studies were performed over 5 days using UV-B-313 fluorescence lamps,which were filtered with a cellulose diacetate film to get increased UV-B treatment and a Mylar film as a control.Pulse-modulated in-vivo chlorophyll fluorescence was used to obtain rapid information of UV-B on photosynthetic processes.The 3-min dark-adapted maximum quantum efficiency of PSII photochemistry,F(v)/F(m),and PSII photochemistry efficiency were measured under natural sunlight.The contents of photosynthetic pigments and UV-B-absorbing compounds were analyzed based on leaf area unit.Important findings Although there was no significant difference,F(v)/F(m) showed a decreasing trend after short-term exposure to enhanced UV-B radiation in all measurements throughout the growing season.The reduction of the actual photochemical quantum efficiency and photochemical quenching as well as the increase of non-photochemical quenching in UV-B supplemented treatment,when compared to the control,indicated therewas a decrease in PSII photochemistry efficiency and an increase in non-photochemical quenching.These phenomena indicated photo-inactivation or photo-damage of photosynthesis occurred in the PSII reaction center.The photosynthetic pigments showed a small decrease in the UV-B supplemented treatment,which may be related to the enhancement of photo-oxidation,a reduction of pigment synthesis and small variation of leaf thickness.The UV-B-absorbing compounds were not influenced by short-term enhancement of UV-B radiation when analyzed based on leaf area unit.This demonstrated that higher contents of UV-B-absorbing compounds in the epidermal layer of alpine plant S.superba were efficient for defense against UV-B radiation and stabilized for further enhancement of UV-B radiation
%K alpine plant
%K photosynthetic pigment
%K PSII photochemistry efficiency
%K Qinghai-Tibetan Plateau
%K Saussurea superba
%K UV-B-absorbing compounds
%K UV-B radiation<br>高山植物
%K 光合色素
%K PSII光化学效率
%K 青藏高原
%K 美丽风毛菊
%K UV-B吸收物质
%K UV-B辐射
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=90BA3D13E7F3BC869AC96FB3DA594E3FE34FBF7B8BC0E591&jid=2F2173CCFF292BF447DC2681EA33BBAE&aid=2599340825A268B687770A25794CBE8C&yid=99E9153A83D4CB11&vid=933658645952ED9F&iid=94C357A881DFC066&sid=5335AD3CFE6E14EA&eid=389DA78D878702A9&journal_id=1005-264X&journal_name=植物生态学报&referenced_num=0&reference_num=0