The responses of Spirulina maxima (blue-green alga) and Chlorella minutissima (green alga) to short-term (6 h) UV-B treatment and long-term (1-80 d) UV-B treatment were investigated using Chlorophyll (Chl) fluorescence, UV spectrophotometer and improved Fridovich method. After short-term treatment (6 h) under different UV-B intensity (0-2.0 w·m-2), FV/FM of the two species were both substantially inhibited, and that of S. maxima were inhibited more than that of C. minutissima. However, the secretion of UV-B absorbing substances and SOD activity in two species after short-time treatment were not related to UV-B. Under long-term treatment (1-80 d) with the same UV-B intensity (0.9 or 1.8 w·m-2), FV/FM of S. maxima were decreased firstly followed by remarkable increasing, while that of C. minutissima were decreased gradually. Within the treatment time, the secretion of UV-B absorbing substances and SOD activity increased gradually in S. maxima, while there are no changes in C. minutissima.
[3] Allen J F. 1992. Protein phosphorylation in regulation of photosynthesis[J]. Biochim Biophysica Acta, 1098:275-335
[4] Campbell D, Eriksson M J, Oqust G, et al. 1998. The cyanobacterium Synechococcus resists UV-B by exchanging photosystem Ⅱ reaction-center D1 proteins[J]. Proc Nat Acad Sci USA, 95:364-369
[5] Canini A, et al. 1992. Superoxide free-living and wild Anabaena and Nostoc (Mostocales, cyonophyta)[J]. Phycologia, 31:223-238
[6] Dunlap W C, Williams, D McB, Chalkert, B E, et al. 1995. UV-absorbing compounds in natural assemblages of Antarctic phytoplankton. Antarct[J]. J. U. S, 30:323-326
[7] Fridovich I. 1975. Superoxide dismutase[J]. Anal Biochem, 44:147-153
[8] Furgal J A. 1997. Ultraviolet radiation and photosynthesis by Georgian Bay phytoplankton of varying nutrient and photoadaptive[J]. Can J Fish Aquat Sci, 54:1659-1667
[9] Govindjee. 1995. Sixty-three years since Kautsky: chlorephyll a fluorescence[J]. Aust J Plant Physiol, 22:131-160
[10] Helbling E W, Villafane V, Ferrario M, et al. 1992. Impact of natural ultraviolet radiation on rates of photosynthesis and on specific marine phytoplankton species[J]. Mar Ecol Prog Ser, 80:89-100
[11] Lao K, Glazer A N. 1996. Ultraviolet-B photodestruction of a light-harvesting compkex[J]. Proc. Natl. Acad. Sci. USA, 93: 5258-5263
[12] Neale P J, Banaszak A T, Jarriel C R. 1998. Ultravioletsunscreens in Gymnodinium sanguineum (dinophyceae): mycosporine-like amino acids protect against inhibition of photosynthesis[J]. J Phycol, 34:928-938
[13] Rall C. 1998. Algal responses to enchanced ultraviolet B radiation[J]. Proc India Nat Sci Acad B: Biol Sci, 64:125-137
[14] van Donk E, Hessen D O. 1996. Loss of flagellain Green alga Chlamydomonas reinhardtii due to in situ UV-exposure[J]. Sci Mar, 60:107-112
[15] Xiong F.1997. Strategies of ultraviolet-B protection in microscopic algae[J]. Physiol Plant, 10:378-38
