La^(3+)对Cd^(2+)胁迫萝卜幼苗的防护效应

Protective Effect of La^(3+) on Radish Seedlings under Cd^(2+) Stress

[目的]为重金属污染植物的生态防御提供参考。[方法]用不同浓度CdCl2(0、1×10-4、5×10-4、1×10-3、5×10-3mol/L)处理萝卜幼苗,各处理整株喷洒等量La(NO3)3溶液(以喷洒等量蒸馏水为对照),研究镧对铬胁迫下萝卜幼苗的防护效应。[结果]镉胁迫下,萝卜幼苗的株高、主根长、根系活力、叶绿素含量和硝酸还原酶活性均有所下降,质膜透性、脯氨酸含量、过氧化氢酶(CAT)及过氧化物酶(POD)活性均显著升高;喷洒一定剂量(15 mg/L)La(NO3)3后,萝卜幼苗的根系活力、叶绿素含量、硝酸还原酶活性均有所升高,质膜透性、脯氨酸含量均有所降低。[结论]适当剂量的稀土元素镧可减轻重金属元素铬对萝卜幼苗的伤害。

[ Objective ] The study was to provide the reference for ecological defense of plants polluted by heavy metals. [ Method ] The radish seedlings were treated by CdCl： with different concn. （0、1×10^-4、5×10^-4、1×10^-3、5×10^-3mol/L）, and the whole plant in each treatment was treated by foliage spray of La（ NO3 ）3 with the same amount（ with the treatment spraying the same amount of distilled water as CK）, the protective effect of La3＋ on radish seedlings under Cd2＋ stress was studied. [ Result ] Under Cd2＋ stress,the plant height,main root length,root activity, chlorophyll content and nitrate reductase activity of radish seedlings were all decreased somewhat, and their membrane permeability, proline content and activities of catalase （CAT） and peroxidase （POD） were all increased somewhat. After spraying of La（ NO3 ）3 with a certain dose （ 15 mg/L） ,the root activity, chlorophyll content and nitrate reductase activity of radish seedlings were all increased somewhat, and their membrane permeability, proline content were all decreased somewhat. [ Conclusion ] Rare earth element La with proper dose could reduce the damage of heavy metal Cd on radish seedlings.