30 1 2009 1 ENVIRONMENTAL SCIENCE Vol 30,No 1 Jan,2009, 3, (, 300071) :, ( ) 2S2 ( GST) ( GPx),, [ Pb(NO 3 ) 2 ] (HgCl 2 ) 96h EC 50 01678 9 mgπl 01140 1 mgπl, AI 01009, 12 h, 70 %, ; GST,, 13104 % ; GPx, 38177 % GST GPx : ; ; ; ; ; GST; GPx :X173 :A :025023301(2009) 0120248206 Individual and Joint Stress of Lead and Mercury on Glutathione2Related Enzymes of Scenedesmus quadrica uda LI Yan, ZHU Lin, LIU Shuo Growth, Glutathione and (Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University,Tianjin 300071,China) Abstract :To understand the toxicity mechanisms of mixed heavy metals on aquatic plant,indicators of algea growth rate,content of reduced glutathione ( ),activities of glutathione S2transferase ( GST) and glutathione peroxidase ( GPx) of green algae, Scenedesmus quadricauda were measured to analyze the individual and joint toxic effects of lead and mercury The results show that the 96h EC 50 of algae growth inhibition by lead [ Pb(NO 3 ) 2 ] and mercury (HgCl 2 ) are 01678 9 mgπl and 01140 1 mgπl respectively After 12 h individual and joint lead and mercury exposure,the content of in alga cells is decreased to about 70 % of the level of the control,and keeps a steady level with the increase of the exposure concentration The GST activities are increased to a peak in lower concentration groups and then decrease with the increase of the exposure concentration Indeed,the higher concentration of lead and mercury combined2poisoning can inhibit the activities of GST significantly, with 13104 % inhibitory rate The activity of GPx is almost suppressed continuously with the increase of the exposure concentration,and the lowest activity is only 38177 % of the control The toxic action of the mixture of Pb and Hg on growth inhibition, content,activities of GST and activities of GPx for Scenedesmus quadricauda are addition Key words : Scenedesmus quadricauda ; lead ; mercury ; joint toxicity ; ; GST; GPx,, ( ) ( GPx) 2S2 ( GST), ( GR), [1,2 ] ROS, GPx (ROS), GST,, (LPX),, ROS, :2008201217 ; :2008203224 : (973) (2004CB418504) : (1977 ),,,,E2mail :hjxyliyan @mail nankai edu cn 3,E2mail :zhulin @nankai edu cn [3 ]
1 : 249 I [4 ] A = A C - A T 100 (1) A C,, I A ; A C ; A T, [5,6 ], (1), 96 h EC 50,,,, 0 ( ), 012 015 018 111 114 mgπl Pb (NO 3 ) 2 0 ( [7,8 ] [9,10 ], ) 0106 0112 0118 0124 0130 mgπl HgCl 2, [11 ],, 3 (2), 96 h EC 50, 015 EC 50 ( ) + 015 EC 50 ( ) = 1 1 0 ( ) 0132 0156 1100 1180 3120 111 (TU ), Pb (NO 3 ) 2 HgCl 2 ( Scenedesmus quadricauda) 1 3, 96 h EC [ Pb (NO 3 ) 50 2 ] (AI) [13 ] Pb (NO (HgCl 2 ), 1 gπl Pb (NO 3 ) 3 ) 2 HgCl 2 2 5 gπl, : HgCl 2 OECD201 [12 ] M = (2) i = 1 EC 50 i 112 11211 M 1,AI = 1-110 (3) M M > 1,AI = M ( - 1) + 110 (4) 250 ml,, M ; c i EC 50 i 100 ml, 1 10 4 ΠmL ; EC 50 i i EC 50 ;AI, 25 1, 3 000 lx, L D = 12 h 12 h, 6 h 1,, 3 11212 [12 OECD201 ], 96 h 24 h 1, XB2K225, Olympus (TU ),, (1) 11213 ( I A ), 72 h,, 96 h EC 50 1 96 h EC 50 n 1 Pb( NO 3 ) 2 HgCl 2 Πmg Table 1 Concentration of Pb(NO 3 ) 2 and HgCl 2 in joint c i treatment groupπmg L - 1 TU Pb(NO 3 ) 2 HgCl 2 0100 0100 01000 0132 0111 01022 0156 0119 01039 1100 0134 01070 1180 0161 01126 3120 1109 01224 L - 1
250 30 = 1 ( TU) 2,, 12 h, 11212 TU, (1) 4 200 rπmin 2 1) ΠTU Table 2 Concentration of Pb(NO 3 ) 2 and HgCl 2 ΠTU Pb(NO 3 ) 2 010 (0 0) 013 (0 203 7) 014 (0 271 6) 016 (0 407 3) 017 (0 475 2) 019 (0 611 0) HgCl 2 010 (0 0) 012 (0 028 0) 014 (0 056 0) 015 (0 070 0) 016 (0 084 0) 018 (0 112 0) Pb(NO 3 ) 2 + HgCl 2 010 (0 0 + 0 0) 1) Πmg L - 1 011 (0 033 6 + 0 006 9) 013 (0 100 9 + 0 020 8) 015 (0 168 2 + 0 034 7) 017 (0 235 5 + 0 048 6) 019 (0 302 8 + 0 062 5) 10 min, 2 3, (ANOVA) LSD,, p 0105 1 4 012 molπl (ph 714), 2 min 4,3 500 2 rπmin 10 min, 211 GPx GST (1) ( I A ), (2) GPx GST 525 2 (22 ) (DTNB) [14 ], GPx Hafemen [15 ],GST Habig [16 ] 96 h EC 50, 3, 96 h EC 50 01678 9 01140 1 mgπl, (3) Bradford [17 ] 4 5 HgCl 2 Pb (NO 3 ) 2, (BSA), 96 h EC 50, gπml, M = 01991 01 11214 AI = 01009 3 212 (Means SD), SPSS 1310 GST GPx 3 96 h EC 50 Table 3 96 h EC 50 of single and joint effects of Pb(NO 3 ) 2 and HgCl 2 on Scenedesmus quadricauda n r 96 h EC 50 95 % Pb(NO 3 ) 2 I A = 53146 c + 13168 3 01996 0 01678 9 mgπl 01597 3 01760 5 HgCl 2 I A = 232158 c + 17142 3 01992 2 01140 1 mgπl 01120 3 01159 9 Pb(NO 3 ) 2 + HgCl 2 I A = - 5177 c 2 + 43171 c + 8194 3 01997 4 01991 0 TU 01884 8 11097 2 21211 ( 80108 % 10149 %) ( 68114 % 12 h, 7147 %), ( p 1, 0105) HgCl 2, 016 TU,,, ( p 0105) 42191 % 6180 %(018 TU, p 0105), 80108 % 10149 % (012 TU, p 0105) 016 TU(63106 % 0192 %, p 0105), 014, 016 017 019 TU
1 : 251 ( p 0105) (68178 % 4167 %,013 TU, p 0105),, (66147 % 1137 %) (75127 % 6138 %),013 019 TU ( p 0105) 2 GST Fig 2 Toxic effects of single and joint Pb(NO 3 ) 2 and HgCl 2 on GST of Scendesmus quadricauda 1 Fig 1 Toxic effects of single and joint Pb(NO 3 ) 2 and HgCl 2 on of Scenedesmus quadricauda 10100 %(019 TU, p 0105) 58133 % 9168 % (018 21212 GST TU, p 0105) 38177 % 8193 % ( 017 TU, p 0105) GST 2,,GST HgCl 2, 014 TU 119125 % 2180 %( p 0105), 85155 % 10172 % (018 TU, p 0105), GST,, ( p 0105) GST 016 TU, 129154 % 3168 % ( p 0105),, GST ( 99177 % 10170 %, 019 TU, p 0105), GST, 011 TU, GPx ( p 0105), GPx 45123 % 3 GPx Fig 3 Toxic effects of single and joint Pb(NO 3 ) 2 and HgCl 2 on GPx of Scenedesmus quadricauda 113187 % 7167 %( p 0105) GST 3, 017 019 TU,,GST 86196 % 3128 %( p, GST 0105) GST mrna [19 21213 GPx ] ROS GPx, GST mrna, 3, GST GST GST
252 30 (48 h),,, (30 d), [20 ],,, GST,, ROS 12 h,,,, GST,,, GST,,, 1975, GST Hutchinson [25 ], GST,,,, AI = 0,, (addition) ; AI < 0, GST,, (antagonism) ; AI > 0,,, (synergism),,, Fern ndez [26 ],,, M 018 112,,, M, = 01991 0,AI = 01009 01,,,,ROS GST, GPx GST GPx,,, GPx GST,, GST, ;, GST GPx, GPx GST, ROS, GPx, GPx,,, GPx, GST GPx, [21,22 ], GPx, [23 ], GPx, GST GPx Okamoto [24 ],
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