重金属胁迫下中肋骨条藻的生理响应及多胺的调节作用研究

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题名	重金属胁迫下中肋骨条藻的生理响应及多胺的调节作用研究
作者	栾红艳1
学位类别	硕士
答辩日期	2015-05-19
授予单位	中国科学院研究生院
授予地点	北京
导师	赵卫红
关键词	Cd2+胁迫 Cu2+胁迫中肋骨条藻生理响应多胺调节作用
学位专业	环境科学
中文摘要	本文分别研究了Cd²⁺和Cu²⁺胁迫下中肋骨条藻（Skeletonema costatum）的生长和细胞内多胺(PAs)的生理响应以及藻细胞内丙二醛(MDA)含量变化以及超氧化物歧化酶(SOD)、二胺氧化酶(DAO)、多胺氧化酶(PAO)活性的变化。另外进一步研究了在这两种重金属胁迫下分别添加外源游离态腐胺(Put)、亚精胺(Spd)和精胺(Spm)的培养实验，探究外源多胺对中肋骨条藻抵抗重金属胁迫的调节作用。 Cd²⁺胁迫下中肋骨条藻的生长受到抑制，随着Cd²⁺浓度的增大，中肋骨条藻细胞的相对增长率降低。藻细胞内丙二醛含量略有升高，超氧化物歧化酶活性显著降低（P<0.001），二胺氧化酶和多胺氧化酶活性分别呈升高趋势。随着Cd²⁺胁迫作用的增强，藻细胞内游离态腐胺、亚精胺、精胺含量先降低后升高；结合态腐胺、亚精胺和精胺含量先升高后降低；束缚态腐胺、亚精胺和精胺的含量及腐胺总量和精胺总量有升高的趋势。表明Cd²⁺胁迫会导致中肋骨条藻细胞产生氧化损害，同时细胞内二胺氧化酶和多胺氧化酶活性的增强以及游离态腐胺、束缚态亚精胺和精胺、腐胺总量和精胺总量的升高可能会增强藻细胞抵抗Cd²⁺胁迫的能力。 Cd²⁺胁迫下中肋骨条藻细胞的相对增长率降低（P<0.05），同时添加亚精胺、精胺后，藻细胞的相对增长率比Cd²⁺胁迫下升高，表明Cd²⁺胁迫能够抑制中肋骨条藻的生长，而添加外源亚精胺、精胺能够缓解Cd²⁺胁迫对中肋骨条藻生长的抑制作用。Cd²⁺胁迫下中肋骨条藻细胞内丙二醛的含量比正常培养的中肋骨条藻细胞内含量升高，对藻细胞的生长产生了一定程度的氧化损害，添加外源游离态亚精胺、精胺后，藻细胞内丙二醛含量比Cd²⁺胁迫组降低，且超氧化物歧化酶的活性比Cd²⁺胁迫组升高，可能是添加的外源亚精胺和精胺通过清除活性氧自由基等反应对Cd²⁺胁迫的氧化损害起到了一定的缓解作用。添加外源亚精胺、精胺后，中肋骨条藻细胞内束缚态腐胺、束缚态亚精胺和束缚态精胺含量都比Cd²⁺胁迫组含量升高，其中束缚态腐胺含量比Cd²⁺胁迫下分别增加了4倍和14.5倍（P<0.01）。由此可见，添加的外源多胺主要通过提高束缚态腐胺、亚精胺和精胺的含量来增强藻细胞对Cd²⁺胁迫的抵抗力。 Cu²⁺胁迫下中肋骨条藻细胞的相对增长率降低，藻细胞内丙二醛含量略有升高，超氧化物歧化酶、二胺氧化酶和多胺氧化酶的活性分别增强，束缚态腐胺和结合态精胺的含量随Cu²⁺浓度的增大而升高。表明Cu²⁺胁迫能够抑制中肋骨条藻的生长，并引起细胞的氧化损害。细胞内超氧化物歧化酶、二胺氧化酶和多胺氧化酶活性的增强以及束缚态腐胺和结合态精胺含量的升高有利于提高藻细胞对于Cu²⁺胁迫的耐受能力。 Cu²⁺胁迫下，中肋骨条藻细胞的相对增长率比正常培养下的藻细胞密度降低，添加外源腐胺，亚精胺，精胺培养的藻细胞的相对增长率有所提高。Cu²⁺胁迫下，中肋骨条藻细胞内丙二醛含量较对照组升高，而同时添加外源腐胺、亚精胺、精胺培养的藻细胞内丙二醛含量比Cu²⁺胁迫下的含量低，且添加外源腐胺、亚精胺、精胺的培养组藻细胞内超氧化物歧化酶活性有升高趋势。表明外源多胺能阻止Cu²⁺胁迫引起的脂质过氧化。添加外源亚精胺、精胺的处理组藻细胞内二胺氧化酶和多胺氧化酶的活性也比Cu²⁺处理组高。对于多胺而言，Cu²⁺胁迫下，藻细胞内结合态腐胺、亚精胺、精胺含量降低，而添加外源多胺的培养组的藻细胞内结合态腐胺、亚精胺、精胺含量有升高趋势。表明结合态多胺可能在中肋骨条藻抵抗Cu²⁺胁迫中起了重要作用。
英文摘要	This thesis studied the growth of Skeletonema costatum under Cd²⁺ stress and Cu²⁺ stress and the changes of MDA and polyamines contents.The activity of SOD, DAO, PAO extracted from Skeletonema costatum were also determined. In order to explore the physiological role of polyamines under heavy metal stress, all the physiological indexes were measured after adding free Put, Spd, Spm under Cd²⁺ stress and Cu²⁺ stress respectively. All the results are as follows: Cd²⁺ stress inhibited the growth of Skeletonema costatum, and the greater the concentration was, the stronger the inhibition would be. With the enhancement of Cd²⁺ stress, MDA content in the Skeletonema costatum cell increased slightly, SOD activity reduced significantly(P<0.001) and DAO, PAO activity enhanced respectively. As the effect of Cd²⁺ stress strengthen, the contents of free putrescine (Put), spermidine (Spd) and spermine (Spm) decreased firstly and increased subsequently; conjugated Put, Spd and Spm contents increased at first and then decreased. However, bound Put, Spm and Spd as well as total Put and total Spm kept increasing. It suggested that Cd²⁺ stress caused oxidation damage to Skeletonema costatum cells. Meanwhile, the enhancement of DAO and PAO activity as well as the increment of free Put, bound Spd and Spm, total Put and total Spm would strengthen the resistance ability of Skeletonema costatum against Cd²⁺ stress. Under Cd²⁺ stress, the relative growth rate of Skeletonema costatum declined(P<0.05), while adding Spd, Spm to the culture medium containing excess Cd²⁺, the relative growth rate of algae increased. It suggests that Cd²⁺ stress inhibit the growth of Skeletonema costatum, while exogenous application of Spd, Spm can mediate the inhibition to the growth of algae cells. The content of MDA in Skeletonema costatum cell increased under the Cd²⁺ stress comparing with the control group, leading to a certain degree of oxidation injury. In the contrary, in the groups of adding Spd, Spm , the contents of MDA decreased compared with the Cd²⁺ stress group, and the activity of SOD enhanced, possibly because exogenous Spd, Spm mediated the oxidation injury through scavenge the reactive oxide species. After applying Spd, Spm, the contents of bound Put, Spd, Spm increased in contrast with Cd²⁺ stress, and the contents of bound Put increased by 4 folds and 14.5 folds respectively than the group of Cd²⁺ stress(P<0.01). This shows exogenous polyamines enhance the resistibility to Cd²⁺ stress by bound Put, Spd, Spm. In the condition of Cu²⁺ stress, the relative growth rate of Skeletonema costatum declined, the content of MDA in the algae cells increased slightly; and the activity of SOD, DAO, PAO extracted from Skeletonema costatum enhanced respectively; the contents of bound Put and conjugated Spm increased as the rise of Cu²⁺ concentration. It indicates that Cu²⁺stress can inhibit the growth of Skeletonema costatum, and cause oxidation injury to algae cell. The enhancement of SOD, DAO, PAO activity and the increment of bound Put and conjugated Spm contents can strengthen the tolerance of Skeletonema costatum to Cu²⁺ stress. Cu²⁺ stress reduced the relative growth rate of Skeletonema costatum compared with the control group; while the application of exogenous Put, Spd, Spm can alleviate the growth inhibition. The content of MDA in algae cells increased under Cu²⁺ stress, however, adding Put, Spd, Spm lowered the content of MDA, and elevated the activity of SOD. These results indicate that polyamines can prevent Cu-induced lipid peroxidation. In addition, the activities of DAO, PAO in the groups of adding Spd, Spm groups enhanced compared with the Cu²⁺ stress. For polyamines, under Cu²⁺ stress, the contents of conjugated Put, Spd, Spm decreased, while adding Put, Spd or Spm to the culture medium, the contents of conjugated Put, Spd, Spm showed rising trends. It demonstrated that conjugated polyamines play a significant role for Skeletonema costatum in resisting Cu²⁺ stress.
语种	中文
学科主题	海洋环境化学
内容类型	学位论文
源URL	[http://ir.qdio.ac.cn/handle/337002/22744]
专题	海洋研究所_海洋生态与环境科学重点实验室
作者单位	1.中国科学院海洋研究所 2.中国科学院大学
推荐引用方式 GB/T 7714	栾红艳. 重金属胁迫下中肋骨条藻的生理响应及多胺的调节作用研究[D]. 北京. 中国科学院研究生院. 2015.