Chin J Plan Ecolo ›› 2011, Vol. 35 ›› Issue (2): 176-186.doi: 10.3724/SP.J.1258.2011.00176

• Research Articles • Previous Articles     Next Articles

Effects of UV-B exclusion on photosynthetic physiology in alpine plant Saussurea superba

SHI Sheng-Bo1,2*, SHANG Yan-Xia2, ZHU Peng-Jin2, ZHANG De-Gang1   

  1. 1College of Pratacultural Science, Key Laboratory of Grassland Ecosystem (GAU) in Ministry of Education, Sino-U.S. Centers for Grazingland Ecosystem Sustainability, Gansu Agricultural University, Lanzhou 730070, China;

    2Key Laboratory of Adaptation and Evolution of Plateau Biology, Northwest PlateauInstitute of Biology, Chinese Academy of Sciences, Xining 810001, China
  • Received:2010-07-05 Revised:2010-09-20 Online:2011-01-21 Published:2011-02-01
  • Contact: SHI Sheng-Bo E-mail:sbshi@nwipb.ac.cn

Abstract:

Aims In the Qinghai-Tibet area, high levels of UV-B radiation reach the earth’s surface as part of strong solar radiation. It is therefore important to examine the response and adaptation of native alpine plants to strong UV-B radiation. Our objective was to determine the physiological response of the photosynthetic apparatus to current ambient UV-B intensity. Methods UV-B-exclusion experiments were conducted on a field site with UV-B-excluding and UV-B-transmitting filters. The two filters transmitted similar levels of photosynthetically active radiation, and there were no differences in air temperature and relative humidity under these metal-frame suspended plastic filters. The experiments were performed in alpine Kobresia humilis meadow with the native alpine species Saussurea superba. Pulse-modulated in vivo chlorophyll fluorescence was mainly used to obtain rapid information on UV-B effects on photosynthetic processes. The trials lasted 15 or 16 days during the growing season of July and August in 2008 and 2009. We measured the 3-min dark-adapted quantum efficiency of PSII photochemistry (F(v)/F(m)), PSII photochemistry efficiency and photosynthetic gas exchange parameters under natural sunlight. The contents of photosynthetic pigments and UV-B-absorbing compounds were analyzed in terms of both leaf area and leaf fresh weight units. Important findings Net photosynthetic rate, significantly increased after removal of UV-B components from natural sunlight. Although there was no significant difference, the F(v)/F(m) was increased in low UV-B treatment compared with the ambient UV-B control. Both the coefficient of photochemical quenching and actual photochemical efficiency of PSII in the light were higher in low UV-B treatment compared to ambient UV-B during the 16 days of continuous measurement during clear days. Variation of PSII maximum efficiency in the light and nonphotochemical quenching further confirmed that the decrease in PSII photochemistry efficiency and increase in nonphotochemical quenching were the results of a strong solar UV-B component in natural sunlight. There was only a slight increase in photosynthetic pigments based both on leaf area and fresh weight after removing UV-B radiation, and these phenomena indicated that strong solar UV-B radiation could photo-oxidize photosynthetic pigments and further accelerate the maturity and senescence of plant cells. UV-B-absorbing compounds were not altered after removal of UV-B radiation, which suggested that high levels of UV-B-absorbing compounds in the epidermal cell layer could protect photosynthetic function from UV-B.

No related articles found!
Viewed
Full text


Abstract

Cited

  Shared   
  Discussed   
[1] Chunhua Zhang Xuanchun Piao Meilan Lian Shouming Wang. Application of Bioreactors in Rapid Propagation of Gypsophila paniculata[J]. Chin Bull Bot, 2007, 24(04): 526 -531 .
[2] Xu Xing-yang;Hong Shu-rong and Wu Li-lian. Induction of plantlets from leaf explants of Emmenoptery henayi in Vitro[J]. Chin Bull Bot, 1983, 1(01): 40 -42 .
[3] Ying Wang Yan Zhou Shumin Gao Rui Liang Yan Liu Li Li Xinde Chen. In vitro Regeneration of Achnatherum splendens (Trin.) Nevski[J]. Chin Bull Bot, 2007, 24(05): 636 -641 .
[4] Wang Ya-fu Liu Zhi-xue Xu qing. The Studies of DNA Me and Non-embryonic Cell Line of Onobrychis Vici Aefolia[J]. Chin Bull Bot, 1991, 8(增刊): 37 -39 .
[5] Wang Le-yuan. A Discussion on the Definitions of Diacytic Type[J]. Chin Bull Bot, 1995, 12(04): 55 -56 .
[6] Ying Liu, Baozhang Chen,Jing Chen,Guang Xu . Applicability of Evapotranspiration Simulation Models for Forest Ecosystems in Qianyanzhou[J]. Chin Bull Bot, 2016, 51(2): 226 -234 .
[7] Meng Fan-jing and Gao Mei-xu. Studies on the Cell Physiological Changes of Root Hairs During Differentiation[J]. Chin Bull Bot, 1985, 3(04): 31 -33 .
[8] Fang Wei Peng Shao-lin He Dao-quan. Population Dynamics of Successional Process of Secondary Forest in Baiyunshan of Guangzhou[J]. Chin Bull Bot, 1995, 12(专辑2): 55 -62 .
[9] Weicai Yang;Dongqiao Shi. Research Advances in Plant Female Gametogenesis[J]. Chin Bull Bot, 2007, 24(03): 302 -310 .
[10] ZHA Li-Hang SU Zhi-GuoZHANG Guo-ZhengOUYANG Fan. Application and Research on Ephedra Resource[J]. Chin Bull Bot, 2002, 19(04): 396 -405 .