摘要
通过沙基培养方法研究不同浓度锌（Zn）对汞（Hg）胁迫下小麦幼苗叶绿素相对含量（SPAD）、丙二醛（MDA）与脯氨酸的积累及抗氧化酶活性等的影响.结果表明：单独Hg（10 mg L-1）胁迫下,小麦幼苗叶绿素含量降低,超氧化物歧化酶（SOD）与过氧化氢酶（CAT）活性受到抑制,MDA与脯氨酸含量升高.加入10 mg L-1Zn后,叶绿素含量比Hg单独胁迫升高了5.6%,MDA含量降低了32.4%,表明该浓度Zn在一定程度上缓解了Hg对小麦幼苗的毒害;Zn浓度高于10 mg L-1的处理中,叶绿素含量逐渐降低,MDA则呈升高趋势,表明随Zn浓度升高,Zn对Hg毒害的缓解作用逐渐降低.低浓度Zn（10~20 mg L-1）提高了Hg胁迫下小麦幼苗SOD与CAT活性,其活性随Zn浓度升高逐渐增加,20mg L-1Zn处理下,两种酶活性比Hg单独胁迫分别升高了103.3%与71.0%,高浓度Zn（50~100 mg L-1）处理下,两种酶活性则呈下降趋势,表明Zn对Hg胁迫下两种酶活性的促进作用逐渐减弱.在试验设置的Zn浓度范围内,脯氨酸含量均低于Hg单独胁迫,并且低于对照,说明外加Zn抑制了脯氨酸的生成.综上所述,10~20 mg L-1的Zn可以在一定程度上缓解10 mg L-1Hg对小麦幼苗造成的毒害.
A sand culture experiment was conducted to investigate the effects of zinc（Zn） with different concentration（10~100 mg L-1） on the chlorophyll relative content（SPAD）,the accumulation of malondialdehyde（MDA） and proline,and the antioxidant enzyme activities of wheat seedlings under mercury（Hg） stress（10 mg L-1）.The results showed that,under the Hg（10 mg L-1） stress treatment alone,the SPAD of wheat seedlings decreased,and both superoxide dismutas（SOD） and catalase（CAT） activities were inhibited,whereas MDA and proline content were increased.When treated together with 10 mg L-1Zn,SPAD increased by 5.6%,MDA levels decreased by 32.4%,indicating that the concentration of Zn to some extent alleviated the toxicity of Hg in wheat seedlings.However,when Zn concentration was higher than 10 mg L-1 SPAD gradually decreased and MDA content significantly increased,suggesting that with the increasing of Zn concentration,Zn alleviation of the toxicity of Hg decreased.Lower concentration of Zn（10~20 mg L-1） promoted the activity of SOD and CAT,which gradually increased with the increasing of Zn concentration.At 20 mg L-1 of Zn,the activities of the two enzymes were increased by 103.3% and 71.0% respectively compared with the Hg treatment alone.Under the higher concentration of Zn（50~100 mg L-1） treatment,the activities of the two enzymes showed downward trends.Within the test concentration,the proline content was lower than that of Hg treatment alone,and less than that of the control,indicating that additional Zn inhibited the formation of proline.In summary,10~20 mg L-1 of Zn eased the wheat seedling poisoning which was caused by Hg at 10 mg L-1 to a certain extent.
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2012年第2期212-217,共6页
Chinese Journal of Applied and Environmental Biology
基金
国家环保公益行业科研专项(No.200809047)资助~~
关键词
锌
汞胁迫
小麦
生理特性
抗氧化酶
Zn
Hg stress
wheat
physiological characteristics
antioxidant enzyme
