UV-B辐射对雨生红球藻光合特性和虾青素含量的影响及其响应  

UV-B EFFECTS ON THE PHOTOSYNTHETIC FEATURES AND ASTAXANTHIN ACCUMULATION OF HAEMATOCOCCUS PLUVIALIS AND ITS RESPONSES

作　　者：肖媛[1,2] 王高鸿[1] 刘永定[1] 

机构地区：[1]中国科学院水生生物研究所,武汉430072 [2]中国科学院研究生院,北京100049

出　　处：《水生生物学报》2010年第6期1077-1082,共6页Acta Hydrobiologica Sinica

基　　金：载人航天项目/国家自然科学基金(30970688)资助

摘　　要：实验研究了不同强度的UV-B(280—320 nm)辐射对雨生红球藻(Haematococcus pluvialis)的光合活性、生物量、色素含量、活性氧(ROS)含量和抗氧化酶活性等的影响,以探讨利用UV-B辐射诱导虾青素生物合成增强的可能性。结果发现,经UV-B辐射处理后,雨生红球藻的光合活性降低、生物量增长被抑制。UV-B辐射对叶绿素影响不大,但会改变细胞的类胡萝卜素和虾青素含量:0.1和0.3 W/m2强度的UV-B辐射使细胞中的这两种色素含量升高,0.5 W/m2组的色素含量短暂升高后恢复到对照水平。中低强度的UV-B可以促进雨生红球藻单细胞虾青素含量的增加,但由于其对细胞生长的抑制作用,并不能使虾青素大量积累。随辐射时间延长,细胞内ROS含量未明显增加,但抗氧化酶(过氧化氢酶和超氧化物歧化酶)活性下降,雨生红球藻可能主要依靠虾青素来淬灭ROS。以上结果表明,UV-B辐射对雨生红球藻的主要生理生化过程有抑制作用,UV-B辐射既可以诱导虾青素的合成又会消耗一部分虾青素,对虾青素含量的影响与其强度有关,而利用虾青素来清除细胞内的ROS可能是雨生红球藻抵御这种不利环境条件的最重要的途径。The effects of UV-B（280nm—320nm） on the dry weight,PSⅡ activity（Fv/Fm）,pigment contents,reactive oxygen species（ROS） accumulation and antioxidant system activities of Haematococcus pluvialis were investigated,which were preliminarily seeking to the feasibility of enhancing the astaxanthin biosyntheses by UV-B irradiation.It was found that UV-B significantly inhibited photosynthetic activity and the increase of biomass of H.pluvialis.UV-B also changed the contents of cellular pigments.Its effects on carotenoid and astaxanthin were stronger than on chlorophyll.UV-B increased the cellular carotenoid and astaxanthin concentrations significantly after 12h-irradiance,whereas the cellular chlorophyll concentrations were indifferent.Then the cellular pigment contents of cells under 0.1 and 0.3 W/m2 UV-B irradiance kept increasing.Simultaneously,the pigment concentrations of 0.5 W/m2 UV-B began to decrease and they were indifferent with control at 24h.A negative correlation was found between the cellular pigment contents and UV-B intensities after a certain time of UV-B treatment.Although 0.1 and 0.3 W/m2 UV-B could induce the astaxanthin accumulation in H.pluvialis cells,the total amounts of astaxanthin were lower than control due to the inhibition of growth.The antioxidant enzymes（CAT and SOD） of H.pluvialis were sensitive to UV-B and they declined as exposure time extended.However,ROS contents did not rise under UV-B.Astaxanthin was a kind of antioxidant and the ROS content was correlated negatively with astaxanthin.It was possible that H.pluvialis eliminated ROS not by increased antioxidant enzyme activity but by astaxanthin under enhanced UV-B condition.In conclusion,UV-B could affect a series of metabolism activities of H.pluvialis and its effects on astaxanthin production depended on the intensity of UV-B.H.pluvialis used astaxanthin to eliminate the harmful ROS and this might be the most important UV-protective strategy which protects the cells from damage of ROS.

关 键 词：雨生红球藻 UV-B 虾青素 ROS 

分 类 号：Q142[生物学—生态学]