镉对集胞藻光合活性的影响
Effects of Cadmium on Photosynthetic Activity of Synechocystis PCC 6803
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摘要: 镉是环境中的主要重金属污染物，研究镉胁迫下蓝藻光合活性的变化，有助于深入认识镉的细胞毒性以及蓝藻细胞对镉胁迫的响应特性，可为评价镉的生态环境风险提供科学依据。为探索镉对淡水蓝藻的毒性效应，选择集胞藻PCC 6803作为受试生物，以0、0.05、0.25、0.50和1.00 mg·L-1 Cd2+处理24 h后，测定其光合色素含量、光合活性以及活性氧(ROS)、超氧化物歧化酶(SOD)的变化。结果表明，0.05 mg·L-1 Cd2+处理下细胞的光合活性与对照组无显著差异；高于0.25 mg·L-1的Cd2+处理，细胞叶绿素a含量下降，PSⅡ反应中心受损，活性氧积累并激活抗氧化酶活性。Cd2+浓度高于0.50 mg·L-1，最大光化学效率(Fv/Fm)显著下降，PSⅡ线性电子传递链受阻；Q-A动力学曲线的快相和中相时长明显增加，QA-到QB电子传递受到抑制，PSⅡ受体侧受损，QB空位点对PQ的结合速率减慢。结果表明，集胞藻能耐受低于0.05 mg·L-1 Cd2+胁迫并表现出毒性兴奋效应；高浓度Cd2+通过干扰PSⅡ导致生长抑制作用，影响线性电子传递链中QA-和QB，主要毒性作用位点(受体蛋白)尚不清楚。Abstract: Cadmium is the main heavy metal pollutant in the current environment. Studying the changes of cyanobacterial photosynthetic activity under cadmium stress is helpful to deeply understand the cytotoxicity of cadmium and the response characteristics of cyanobacterial cells to cadmium stress. In order to provide basis for evaluating the ecological and environmental risks of cadmium, toxic effects of cadmium to freshwater cyanobacteria was studied, selecting Synechocystis PCC 6803 as the test organism. After treatment with 0, 0.05, 0.25, 0.50 and 1.00 mg·L-1 Cd2+ for 24 h, the content of photosynthetic pigments, photosynthetic activity, reactive oxygen species (ROS) content and superoxide dismutase (SOD) activities were determined. The results showed that there was no significant difference in photosynthetic activity between the low-dose 0.05 mg·L-1 Cd2+ treatment and the control group. Under treatment with 0.25 mg·L-1 Cd2+, chlorophyll a content decreased, the PSⅡ reaction center was damaged, ROS content was accumulated, the antioxidant enzyme was activated and growth was inhibited. The maximum photochemical efficiency (Fv/Fm) decreased significantly at Cd2+ concentrations above 0.50 mg·L-1, and the linear electron transport chain of PSⅡ was blocked. The fast and middle phases of the Q-A reoxidation kinetics curve became significantly longer, inhibiting electron transfer between QA- and QB, impairing the receptor side of PSⅡ, and slowing down the binding rate between the vacancy site of QB and PQ. The results showed that Synechocystis PCC 6803 could tolerate less than 0.05 mg·L-1 Cd2+ stress and Cd2+ exhibited stimulant effects; high concentrations of Cd2+ cause growth inhibition by interfering with PSⅡ, affecting QA- and QB in the linear electron transport chain, and the main toxic sites of action of cadmium (receptor proteins) are not known.
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Key words:
- Cd2+ /
- Synechocystis PCC 6803 /
- photosynthetic activity /
- antioxidant enzyme activity /
- toxic effects
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Wagner G. Accumulation of cadmium in crop plants and its consequences to human health[J]. Advances in Agronomy, 1993, 51:173-212 Tukaj Z, Baścik-Remisiewicz A, Skowroński T, et al. Cadmium effect on the growth, photosynthesis, ultrastructure and phytochelatin content of green microalga Scenedesmus armatus:A study at low and elevated CO2 concentration[J]. Environmental and Experimental Botany, 2007, 60(3):291-299 Xia X, Wu S J, Zhou Z J, et al. Microbial Cd(Ⅱ) and Cr(Ⅵ) resistance mechanisms and application in bioremediation[J]. Journal of Hazardous Materials, 2021, 401:123685 Ammendola S, Cerasi M, Battistoni A. Deregulation of transition metals homeostasis is a key feature of cadmium toxicity in Salmonella[J]. BioMetals, 2014, 27(4):703-714 Rani A, Kumar A, Lal A, et al. Cellular mechanisms of cadmium-induced toxicity:A review[J]. International Journal of Environmental Health Research, 2014, 24(4):378-399 Aimola P, Carmignani M, Volpe A R, et al. Cadmium induces p53-dependent apoptosis in human prostate epithelial cells[J]. PLoS One, 2012, 7(3):e33647 Srivastava A, Biswas S, Yadav S, et al. Acute cadmium toxicity and post-stress recovery:Insights into coordinated and integrated response/recovery strategies of Anabaena sp. PCC 7120[J]. Journal of Hazardous Materials, 2021, 411:124822 Blasi B, Peca L, Vass I, et al. Characterization of stress responses of heavy metal and metalloid inducible promoters in synechocystis PCC6803[J]. Journal of Microbiology and Biotechnology, 2012, 22(2):166-169 Luo Z X, Wang Z H, Liu A F, et al. New insights into toxic effects of arsenate on four Microcystis species under different phosphorus regimes[J]. Environmental Science and Pollution Research International, 2020, 27(35):44460-44469 Zhou W B, Juneau P, Qiu B S. Growth and photosynthetic responses of the bloom-forming cyanobacterium Microcystis aeruginosa to elevated levels of cadmium[J]. Chemosphere, 2006, 65(10):1738-1746 Wang Y, Wang J C, Zhang H H, et al. A intermediate concentration of atmospheric nitrogen dioxide enhances PSⅡ activity and inhibits PSⅠ activity in expanded leaves of tobacco seedlings[J]. Ecotoxicology and Environmental Safety, 2021, 209:111844 Yu Z, Hao R, Zhang L, et al. Effects of TiO2, SiO2, Ag and CdTe/CdS quantum dots nanoparticles on toxicity of cadmium towards Chlamydomonas reinhardtii[J]. Ecotoxicology and Environmental Safety, 2018, 156:75-86 Faller P, Kienzler K, Krieger-Liszkay A. Mechanism of Cd2+ toxicity:Cd2+ inhibits photoactivation of photosystem Ⅱ by competitive binding to the essential Ca2+ site[J]. Biochimica et Biophysica Acta (BBA)-Bioenergetics, 2005, 1706(1-2):158-164 Liu M Q, Yanai J, Jiang R F, et al. Does cadmium play a physiological role in the hyperaccumulator Thlaspi caerulescens?[J]. Chemosphere, 2008, 71(7):1276-1283 Poole J H, Tyack P L, Stoeger-Horwath A S, et al. Animal behaviour:Elephants are capable of vocal learning[J]. Nature, 2005, 434(7032):455-456 Glatz A Vass I, Los D A, et al. The Synechocystis model of stress:From molecular chaperones to membranes[J]. Plant Physiology and Biochemistry, 1999, 37(1):1-12 Igiri B E, Okoduwa S I R, Idoko G O, et al. Toxicity and bioremediation of heavy metals contaminated ecosystem from tannery wastewater:A review[J]. Journal of Toxicology, 2018, 2018:2568038 Deng L P. Sorption and desorption of lead (Ⅱ) from wastewater by green algae Cladophora fascicularis[J]. Journal of Hazardous Materials, 2007, 143(1-2):220-225 Ao D, Lei Z, Dzakpasu M, et al. Role of divalent metals Cu2+ and Zn2+ in Microcystis aeruginosa proliferation and production of toxic microcystins[J]. Toxicon:Official Journal of the International Society on Toxinology, 2019, 170:51-59 Shivaji S, Dronamaraju S V L. Scenedesnus rotundus isolated from the petroleum effluent employs alternate mechanisms of tolerance to elevated levels of cadmium and zinc[J]. Scientific Reports, 2019, 9:8485 Newby R Jr, Lee L H, Perez J L, et al. Characterization of zinc stress response in Cyanobacterium synechococcus sp. IU 625[J]. Aquatic Toxicology, 2017, 186:159-170 Tóth T, Zsiros O, Kis M, et al. Cadmium exerts its toxic effects on photosynthesis via a cascade mechanism in the cyanobacterium, Synechocystis PCC 6803[J]. Plant, Cell & Environment, 2012, 35(12):2075-2086 Lichtenthaler H K. Chlorophylls and carotenoids:Pigments of photosynthetic biomembranes[J]. Methods in Enzymology, 1987, 148:350-382 Pan X L, Zhang D Y, Chen X, et al. Effects of levofloxacin hydrochloride on photosystem Ⅱ activity and heterogeneity of Synechocystis sp.[J]. Chemosphere, 2009, 77(3):413-418 Maxwell K, Johnson G N. Chlorophyll fluorescence-A practical guide[J]. Journal of Experimental Botany, 2000, 51(345):659-668 Wang S Z, Zhang D, Pan X. Effects of arsenic on growth and photosystem Ⅱ (PSⅡ) activity of Microcystis aeruginosa[J]. Ecotoxicology and Environmental Safety, 2012, 84:104-111 Beauchemin R, Gauthier A, Harnois J, et al. Spermine and spermidine inhibition of photosystem Ⅱ:Disassembly of the oxygen evolving complex and consequent perturbation in electron donation from TyrZ to P680+ and the quinone acceptors Q-A to QB[J]. Biochimica et Biophysica Acta (BBA)-Bioenergetics, 2007, 1767(7):905-912 Wodala B, Deák Z, Vass I, et al. In vivo target sites of nitric oxide in photosynthetic electron transport as studied by chlorophyll fluorescence in pea leaves[J]. Plant Physiology, 2008, 146(4):1920-1927 Kaftan D, Meszaros T, Whitmarsh J, et al. Characterization of photosystem Ⅱ activity and heterogeneity during the cell cycle of the green alga Scenedesmus quadricauda[J]. Plant Physiology, 1999, 120(2):433-442 Pan X L, Deng C N, Zhang D Y, et al. Toxic effects of amoxicillin on the photosystem Ⅱ of Synechocystis sp. characterized by a variety of in vivo chlorophyll fluorescence tests[J]. Aquatic Toxicology, 2008, 89(4):207-213 杨雨嘉, 支崇远, 李培林, 等. 重金属Cd2+和Cu2+对一种曲壳藻生长情况及其抗氧化酶活性的影响[J]. 生态科学, 2015, 34(6):75-80 Yang Y J, Zhi C Y, Li P L, et al. Effects of heavy metal Cd2+ and Cu2+ on growth and antioxidant enzymes of Achnanthes kryophila[J]. Ecological Science, 2015, 34(6):75-80(in Chinese)
Latifi A, Ruiz M, Zhang C C. Oxidative stress in cyanobacteria[J]. FEMS Microbiology Reviews, 2009, 33(2):258-278 Rutherford A W, Krieger-Liszkay A. Herbicide-induced oxidative stress in photosystem Ⅱ[J]. Trends in Biochemical Sciences, 2001, 26(11):648-653 Ezraty B, Gennaris A, Barras F, et al. Oxidative stress, protein damage and repair in bacteria[J]. Nature Reviews Microbiology, 2017, 15(7):385-396 Govindje E. Sixty-three years since Kautsky:Chlorophyll a fluorescence[J]. Functional Plant Biology, 1995, 22(2):131-160 Zhang X, Chen H, Wang H, et al. Time-course effects of Tris(1,3-dichloro-2-propyl) phosphate (TDCPP) on Chlorella pyrenoidosa:Growth inhibition and adaptability mechanisms[J]. Journal of Hazardous Materials, 2021, 402:123784 T[AKu。]mová E, Sofrová D. Response of intact cyanobacterial cells and their photosynthetic apparatus to Cd2+ ion treatment[J]. Photosynthetica, 2002, 40(1):103-108 苏甜, 李义刚, 欧瑞康, 等. 镉离子对羊角月牙藻光合作用及其抗氧化酶的毒性影响[J]. 生态科学, 2014, 33(2):301-306 Su T, Li Y G, Ou R K, et al. Toxic effects of Cd2+ on the photosynthesis and antioxidase activity of Selenastrum capricornutum[J]. Ecological Science, 2014, 33(2):301-306(in Chinese)
邱昌恩, 况琪军, 毕永红, 等. Cd2+对绿球藻生长及生理特性的影响研究[J]. 水生生物学报, 2007, 31(1):142-145 Qiu C G, Kuang Q J, Bi Y H, et al. The effects of Cd2+ on the growth and physiological characteristics of chlorococcum sp.[J]. Acta Hydrobiologica Sinica, 2007, 31(1):142-145(in Chinese)
聂利华, 杨东娟, 刘亚群, 等. 一株虾池来源的螺旋拟柱孢藻藻株的分离鉴定及重金属离子Cu2+、Cd2+和Pb2+对其生长的影响[J]. 微生物学报, 2019, 59(7):1307-1317 Nie L H, Yang D J, Liu Y Q, et al. Isolation, identification and effect of heavy metals on the growth of Cylindrospermopsis raciborskii helix from shrimp ponds[J]. Acta Microbiologica Sinica, 2019, 59(7):1307-1317(in Chinese)
Xu C X, Sun T, Li S B, et al. Adaptive laboratory evolution of cadmium tolerance in Synechocystis sp. PCC 6803[J]. Biotechnology for Biofuels, 2018, 11:205 -
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