小球藻(Chlorella...紫外辐射的光合生理特性研究_杨雨玲.pdf

生态毒理学报Asian Journal of Ecotoxicology第 17 卷 第 6 期 2022 年 12 月Vol.17,No.6 Dec.2022 基金项目:安徽省重点研究与开发计划项目(202004i07020004);国家自然科学青年基金项目(31600317);安徽省高校自然科学研究重点项目(KJ2021A1038);安徽省教育厅高校优秀青年人才支持计划一般项目(gxyq2021212);安徽省教育厅自然科学一般项目(KJHS2018B08);大学生创新创业项目(201910375011,S201910375018);黄山学院新安江流域生态环境保护研究中心(kypt202102)第一作者:杨雨玲(1986),女,硕士研究生,研究方向为藻类生理生态学,E-mail: *通信作者(Corresponding author),E-mail:DOI:10.7524/AJE.1673-5897.20211207001杨雨玲,章鹏,李亚鹤,等.小球藻(Chlorella vulgaris)耐受短期模拟酸雨及紫外辐射的光合生理特性研究J.生态毒理学报,2022,17(6):315-324Yang Y L,Zhang P,Li Y H,et al.Study on photosynthetic physiological characters ofChlorella vulgarisunder stress of short-term simulated acid rainand UV radiation J.Asian Journal of Ecotoxicology,2022,17(6):315-324(in Chinese)小球藻(Chlorella vulgaris)耐受短期模拟酸雨及紫外辐射的光合生理特性研究杨雨玲1,2,3,章鹏3,4,李亚鹤1,蔡飞2,3,毕淑峰2,3,李伟2,3,*1.宁波大学海洋学院,宁波 3152112.黄山学院生命与环境科学学院,黄山 2450413.黄山学院新安江流域生态环境保护研究中心,黄山 2450414.黄山市屯溪区林业局,黄山 245041收稿日期:2021-12-07 录用日期:2022-02-21摘要:为了解新安江流域优势藻类对短期模拟酸雨及紫外辐射的光合生理响应,选取流域分离的一株绿藻门小球藻(Chlorellavulgaris)为对象,通过模拟酸雨引起的水体 pH 值降低(5.65 和 4.50),研究了短期(24 h)酸胁迫下该种在低光(60 mol m-2 s-1)与高光(150 mol m-2 s-1)培养时生长及光合活性的响应,并探讨了上述条件下该种对短期紫外辐射(UVR)的敏感性。结果表明,相较于对照组(pH 值 7.10),仅较低的 pH 值(4.50)显著抑制了小球藻生长并改变了其细胞形态(高光下细胞粒径显著降低)。高光培养而非低 pH 胁迫显著降低藻体光合色素含量(叶绿素a、叶绿素b);光保护色素(类胡萝卜素、三苯甲咪唑类氨基酸(MAAs)整体上未受光强或 pH 值影响。高光培养的藻体有效光化学效率(Yield)在低 pH 值下显著降低,而低光处理下各 pH值处理间无显著差别。低光下培养的藻,经阳光模拟器下辐射处理后(可见光(P):87.5 W m-2、紫外线 A(UVA):33.5 W m-2、紫外线 B(UVB):1.91 W m-2),Yield 在低 pH 值(5.65、4.50)下整体低于高光处理组,且 UVR 对 Yield、最大相对电子传递速率(rETRmax)、光能利用效率()的抑制率在低 pH 值、低光下更为显著。研究结果表明,藻细胞经历的光环境(高、低光强)可显著影响其对水体酸化与 UVR 耦合效应响应。关键词:模拟酸雨;紫外辐射;小球藻;光合生理文章编号:1673-5897(2022)6-315-10 中图分类号:X171.5 文献标识码:AStudy on Photosynthetic Physiological Characters of Chlorella vulgaris un-der Stress of Short-term Simulated Acid Rain and UV RadiationYang Yuling1,2,3,Zhang Peng3,4,Li Yahe1,Cai Fei2,3,Bi Shufeng2,3,Li Wei2,3,*1.School of Marine Sciences,Ningbo University,Ningbo 315211,China2.College of Life and Environmental Sciences,Huangshan University,Huangshan 245041,China3.Eco-Environmental Conservation Research Centre of Xinanjiang River Basin,Huangshan University,Huangshan 245041,China4.Forestry Bureau of Tunxi District,Huangshan City,Huangshan 245041,ChinaReceived 7 December 2021 accepted 21 February 2022316 生态毒理学报第 17 卷Abstract:To learn the photosynthetic physiological response of dominant algae in Xinanjiang River basin toshort-term simulated acid rain(pH 5.65 and 4.50)and ultraviolet radiation(UVR),a strain ofChlorella vulgarisiso-lated from the river basin was selected as the object.The response of growth and photosynthetic activity of thisspecies to short-term(24 h)acid stress were studied under low light(60 mol m-2 s-1)and high light(150 mol m-2 s-1),and the sensitivity of photosystem to short-term ultraviolet radiation(UVR)treatment under the a-bove conditions was discussed.The results showed that only the low pH value(4.50)significantly inhibited thegrowth and changed the cell morphology(the cell size decreased significantly under high light)ofC.vulgarisincomparison with the control group(pH 7.10).High light culture instead of low pH stress significantly reduced thephotosynthetic pigment content(Chla,Chlb)ofC.vulgaris.The photoprotective pigments of carotenoids and my-cosporine-like amino acids(MAAs)were generally not affected by light intensity or pH value.The effective quan-tum yield(Yield)cultured in high light decreased significantly at low pH value,but there was no significant differ-ence among different pH values under low light treatment.The algae cultured in low light,after being irradiated bysolar simulator with high photosynthetically active radiation(photosynthetically active radiation,P:87.5 Wm-2)and UVR(ultraviolet A,UVA:33.5 W m-2,ultraviolet B,UVB:1.91 W m-2),Yield were lower than that of highlight treatment group at low pH(5.65,4.50),and the inhibition rate of UVR on Yield,maximum relative electrontransfer rate(rETRmax)and light using efficiency()was more significant at low pH and low light.The resultsshowed that the light environment(high and low light intensity)experienced by algae cells can significantly affectthe coupling effect of water acidification and UVR.Keywords:simulated acid rain;UV radiation;Chlorella vulgaris;photosynthetic physiology 浮游植物作为内陆水域生态系统中初级生产力的重要组成,是构成食物网的基础,在生物地球化学循环中扮演重要角色。环境因子如何影响、调节浮游植物的光合生理、初级生产、种群结构及丰度是生态学研究的重要内容。因空间位置(经、纬度)、水体类型(湖泊、河流)、局域环境条件的不同,影响浮游植物光合生理、群落结构的主要环境因子在不同流域存在一定差异。黄山市是世界文明的生态旅游城市,同时也是我国受酸雨影响较大的城市之一(可参见历年的中国生态环境状况公报)。酸雨引起的水体酸化是影响新安江流域浮游植物的重要胁迫因子。水体酸化可影响浮游植物色素含量1-2、增加耐酸性基因表达3、影响光合生理过程、抑制生长,进而影响群落结构组成4-5。前期的研究表明,新安江流域浮游植物多样性及丰度在短期酸胁迫下整体呈降低趋势,且不同门类浮游植物的敏感性不同6,这可能与种间/株系间差异性有关7。淡水水体因溶解有机质含量、水体 pH 值等因素的影响,水体透光率存在较大差异,从而使到达水体的光质及光强发生改变。对浮游植物光合作用及初级生产过程来说,阳光光谱中可见光(P,400 700nm)与紫外光(UVR,包括 320 400 nm 紫外线 A(UVA)和 280 320 nm 紫外线 B(UVB)是最为重要的部分。作为水质全年总体较优(类或类以上占比较高)的水系(浊度较低)8-9,长期酸雨背景下将进一步提高水体透明度,从而增加可见光(P)及紫外辐射(UVR)在水中的强度与透射深度。UVR 可单独或与高光强耦合降低浮游植物的光合速率10,抑制营养盐吸收11-12,诱导细胞 DNA、RNA 突变以及活性氧自由基的产生13-14,导致生产力的降低12。针对新安江流域(屯溪段)浮游植物群落结构与环境因子的研究也表