摘要
为探索酸化土壤与镉对大豆萌发种子抗氧化保护酶的复合影响,采用种子常规萌发试验的方法,模拟pH=5.93和pH=2.5的酸化土壤,并用0.182mg·L^(-1)和20mg·L^(-1)的Cd^(2+)处理大豆种子,测定不同酸化土壤及镉浓度胁迫对大豆萌发种子过氧化物酶(POD)、过氧化氢酶(CAT)、丙二醛(MDA)和质膜透性的影响。结果表明,轻度酸化土壤(pH=5.93)或低质量浓度镉(0.182mg·L^(-1))可激活POD与CAT活性,降低MDA含量及质膜透性,且与胁时相关;复合处理上述效应更显著,但随胁时延长4指标变幅加大,膜系统恢复时间推后。重度酸化土壤(pH=2.5)与高质量浓度镉(20mg·L^(-1))胁迫下的POD与CAT活性随胁时延长而降低,MDA含量及质膜透性则随胁时延长而升高;低-高、高-高复合处理时,4指标随胁时延长变幅更大,7d时偏离CK更显著,且CAT、MDA和质膜透性峰值推后。由此可见,酸化土壤与镉复合污染可加剧对种子萌发的伤害,二者存在协同作用。
The purpose of our research is to explore the multifaceted effects of acidified soil and cadmium on the antioxidative protective enzymes during the seed germination of soybean. In doing our experiments, we have simulated two kinds of acidified soil with pH = 5.93 and pH=2.5, and the neutral solution （pH=7.0） as control. Thetwo concentrations of Cd2＋ were 0.182 and 20mg·L^-1
. First of all, we have disinfected the soybean seeds for 8 minutes by using HgCl2 pretreated with corresponding solution for 24 hours. Then, we placed the pretreated soybean seeds into culture dishes with filter sheets, letting them germinate in a cultivated container keeping at the constant temperature of 25℃ , in which each group to be treated involved three dishes with 100 seeds in each, respectively. The seeds were placed and submerged in the corresponding solution at a depth of about two-thirds of the seeds. In the germinating process, the seeds were let to be exposed to the corresponding solution that was replaced everyday, for 7 d until the germination was completed. And then the POD, CAT, MDA, as well as membrane permeability were tested and measured under the different degrees of stress everyday. The resuits show that POD and CAT activity had been increased, with the MDA content and membrane permeability decreased under the mild acidified soil （pH = 5.93） or Cd2＋ （0.182 mg·L^-1） stress, and the four indexes related to the stress time respectively. The same phenomena have also been found in the process of seed germination. But the four indexes were found changed dramatically and more time needed to get recovered. As the stress time progresses, the severe acidified soil （ pH = 2.5 ） and Cd2 ＋（ 20 mg·L^-1 ） stress were found inhibiting POD and CAT activity, whereas MDA content membrane permeability kept increasing. When simulated acidified soil and Cd2＋ were jointly used, the four indexes began to fluctuate severely and seriously deviated from the control on the 7th day. Therefore, it can be concluded that the multifaceted effects of acidified soil and cadmium can aggravate the damage on the soybean seed germination for the effects among them were synergistic in nature.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2010年第4期5-8,共4页
Journal of Safety and Environment
基金
高等学校教育教学改革项目(3-26-77)
关键词
环境学
大豆萌发种子
酸化土壤
镉
抗氧化保护酶
复合影响
environmentalology
soybean seed germination
acidified soil
cadmium
antioxidative protective enzymes
complex effects
