铅胁迫对木榄幼苗抗氧化酶的影响

Effects of lead stress on antioxidant enzymes in Bruguiera gymnorrhiza seedlings

用含不同浓度Pb(NO3)2(0～40mmol.L-1)的Hoagland营养液处理沙培中的木榄(Bruguiera gymnorrhiza)幼苗,2个月后测定幼苗过氧化物酶(POD)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性并对其同工酶进行电泳分析。结果表明,1～10mmol.L-1Pb促进幼苗根和叶中抗氧化酶活性,但在20～40mmol·L-1Pb高浓度下,酶活性下降。电泳结果显示,Pb主要影响阴离子型POD同工酶活性。20～40mmol·L-1Pb强烈抑制根中所有CAT同工酶的活性;30～40mmol·L-1Pb诱导出1条新的Cu/Zn-SOD同工酶LS-3和3条新的CAT同工酶RC-3、LC-2和LC-3。

Bruguiera gymnorrhiza seedlings in sandy culture were treated with Hoagland nutrient solution containing 0-40 mmol · L^-1 of Pb（ NO3 ） 2- After treated for two months, the activities of peroxidase （POD）, superoxide dismutase （SOD）, and catalase （CAT） were determined, and their isoenzymes were analyzed by electrophoresis. The results showed that the activities of antioxidant enzymes in B. gymnorrhiza seedlings roots and leaves increased under 1-10 mmol ·L^-1 Pb but decreased under 20-40 mmol · L^-1 Pb. Lead mainly affected the activities of anion type POD isoenzymes. 20- 40 mmol ·L^-1 Pb strongly inhibited the activities of all CAT isoenzymes in roots, while 30-40 mmol· L^-1pb induced one additional Cu/Zn-SOD isoenzyme LS-3 and three additional CAT isoenzymes RC-3, LC-2, and LC-3.