基于拟南芥的氧化石墨烯毒性效应与转运研究

发布时间：2018-03-07 00:34

本文选题：拟南芥　切入点：氧化石墨烯　出处：《南京农业大学》2015年硕士论文　论文类型：学位论文

【摘要】：纳米技术包括制造和使用不同的工程纳米材料,如金属纳米材料,量子点,和碳纳米材料等。随着纳米材料在工业和医学领域的大规模生产和使用,使得人们更加关心其对健康和环境的影响。氧化石墨烯(graphene oxide,GO)是石墨烯家族中重要的一员,由于其独特的性能和2维结构,在工业和医学领域有着巨大的应用潜质。体内和体外实验数据都表明GO对生物有害。随着纳米材料的不断生产和应用,植物可能从环境中吸收工程纳米材料,进一步通过导管运输到各个组织中。同时,一系列证据表明,长时间或高浓度的GO暴露能够对生物体产生不利的影响,导致GO在细胞或生物体中沉淀。相对而言,对于环境相关剂量GO的生物学效应所知甚少。因此,本论文致力于利用拟南芥植物为载体研究体系,分析环境相关剂量GO对于植物发育及生理的影响。考虑到工程纳米材料释放到环境中的浓度范围在ng/L或mg/L,选择GO暴露浓度为ug/L来评价GO的生物学效应。首先分析了在正常生理条件下环境相关剂量GO对拟南芥植物的影响。在正常生理条件下,经10-1000 ug/L GO处理后,对拟南芥种子萌发和发育没有影响,对子叶和根的生长没有明显的作用,拟南芥的开花进程没有改变,发育过程也没有受到影响。拟南芥中各种抗氧化酶如SOD和CAT活性没有改变,MDA含量没有明显变化。经分析浓度的GO暴露后,拟南芥仍然能够维持正常的生理状态。同时,分析了与发育相关的基因的表达模式,发现拟南芥中与种子萌发、光形态建成、根发育、营养生长到生殖生长转迁相关基因的表达模式都没有明显的变化。也就是说,经分析浓度GO暴露后拟南芥的发育没有发生潜在变化。电镜分析GO在拟南芥细胞中的转运,在叶肉细胞和筛管组织中没有发现GO聚集,在茎薄壁细胞的细胞质中、根的筛管组织中只发现少量的GO。但在根毛和根的薄壁组织的细胞质中发现大量的GO聚集。这一结果说明,GO很容易被拟南芥根毛吸收,沉积在根的薄壁细胞中,但是很难从根转移到茎和叶中。其次,分析了胁迫生理条件下环境相关剂量GO对拟南芥植物的影响。本实验选用了两种广泛研究并经常发生的胁迫(干旱胁迫和盐胁迫)来研究和GO共同暴露的影响。PEG6000的浓度选择20%,NaCl的浓度选择200 mmol/L。选择PEG6000(20%)和NaCl(200 mmol/L)是因为,这些浓度对拟南芥能够产生适度不利的影响,这有助于我们观察GO和PEG6000或NaCl共同处理产生的可能更加严重的不利影响。与正常生理条件不同的是,在胁迫条件下GO能够诱导拟南芥产生更加严重的不利影响。在本研究实验条件下,PEG6000(20%)或 NaCl(200 mmol/L)和 1000 μg/L GO 共同处理比PEG6000(20%)或NaCl(200 mmol/L)单独处理对拟南芥幼苗的形态、鲜重、根长、根冠比产生更加严重的不利影响,导致H202含量和产生的ROS水平增加更加严重,导致更加严重的SOD含量和CAT含量下降。同时发现与发育相关的分子基础被改变了,PEG6000(20%)或 NaCl(200 mmol/L)和 1000 μg/L GO 共同处理后,与PEG6000(20%)或NaCl(200 mmol/L)单独处理相比,与根发育相关基因、与非生物胁迫相关基因的表达模式都发生严重的变化。细胞水平分析发现,与GO单独处理相比,PEG6000(20%)或 NaCl(200 mmol/L)和 1000 μg/L GO 共同处理拟南芥后,GO更加严重分布积累在拟南芥的根、叶和气孔中。我们因此提出,在胁迫条件下,G0能够诱导氧化应激和膜离子渗漏,从而导致GO被从根运输到叶中。我们的结果将有助于理解在不同环境条件下G0的毒性及转运。
[Abstract]:Nanotechnology including manufacturing and engineering use of different nano materials, such as metal nanoparticles, quantum dots, and carbon nano materials with nano materials in industrial and medical fields of mass production and use, make people more concerned about its impact on health and the environment. Shi Moxi (graphene oxide, GO oxidation) is one of the most important family member of graphene, due to its unique properties and 2 dimensional structure, has great application potential in industrial and medical fields. In vivo and in vitro data indicate that GO is harmful to organism. With the continuous production and application of nano materials, nano materials engineering plant may be absorbed from the environment, further through the catheter to transport all tissues. At the same time, a series of evidence, can have an adverse effect on the organisms long time or high concentrations of GO exposure, resulting in GO precipitation in cells or organisms. For the The biological effects of environmental dose of GO are poorly understood. Therefore, this thesis aims at using Arabidopsis thaliana plants as carrier research system, analysis of the impact of environmental dose GO for the development and physiology of plants. Considering the release of engineered nanomaterials to a range of concentrations in the environment of ng/ L or mg/L GO, the biological effects of exposure to ug/L to evaluate the concentration of GO. The first analyzes the impact of environment related dose of GO of Arabidopsis plants under normal physiological conditions. Under normal physiological conditions, by 10-1000 ug/L after GO treatment on Seed Germination of Arabidopsis development and has no impact on the growth of Ye Hegen, there was no significant effect of Arabidopsis flowering process, has not changed, too no developmental process is influenced by various antioxidant enzymes in Arabidopsis. Such as SOD and CAT activity did not change, the content of MDA did not change significantly. By analyzing the concentration of GO after exposure, Arabidopsis Still can maintain the normal physiological state. At the same time, analysis of the expression pattern and development related gene, found in Arabidopsis and photomorphogenesis, seed germination, root development, expression pattern of vegetative growth to reproductive growth transition related genes have no obvious change. That is to say, through the analysis of the concentration of GO after exposure of Arabidopsis thaliana the development of potential changes. Electron microscopy analysis of GO transporter in Arabidopsis cells, no accumulation of GO found in the mesophyll cells and tissues in the screen, thin stem cell cytoplasm, the root of the sieve tissue showed that only a small amount of GO. but in the parenchyma of the root hair and root in the cytoplasm of the GO found that a large number of aggregation this result suggests that GO is easy to be absorbed in the deposition of Arabidopsis root hairs, parenchyma cells of root, but it is difficult to transfer from root to stem and leaf. Secondly, analyzes the stress under physiological conditions of environment related agent Effect of GO on Arabidopsis plants. This study selected two widely studied and frequently occurring stress (drought stress and salt stress) to study the effect of the concentration of.PEG6000 and GO CO exposure to 20% NaCl, the concentration of 200 mmol/L. PEG6000 (20%) and NaCl (200 mmol/L) is because the concentration of can produce the effect of moderate adverse to Arabidopsis, which helps us to observe GO and PEG6000 or NaCl common adverse effects from the treatment may be more severe. Unlike the normal physiological conditions, under stress conditions can be induced by GO in Arabidopsis thaliana. The more serious adverse effects in the experimental conditions, PEG6000 (20%) or NaCl (200 mmol/L) and 1000 g/L GO treatment than PEG6000 (20%) or NaCl (200 mmol/L) alone treatment on Arabidopsis seedling morphology, fresh weight, root length, root and shoot more serious adverse effects than, guide Due to the content of H202 and the levels of ROS produced more serious, leading to decreased SOD content and CAT content is more serious. At the same time that the molecular basis and development related changes, PEG6000 (20%) or NaCl (200 mmol/L) and 1000 g/L GO treated with PEG6000 (20%) or NaCl (200 mmol/L compared with the single treatment), gene expression pattern and root development, abiotic stress related genes have undergone serious changes. Cell level analysis showed that treatment with GO alone compared to PEG6000 (20%) or NaCl (200 mmol/L) and 1000 g/L GO treatment of Arabidopsis, GO accumulation in the distribution of more serious Arabidopsis root, leaf and stomata. We therefore propose, in stress conditions, G0 can induce oxidative stress and membrane ion leakage, resulting in GO from the root to leaf transport. Our results will be helpful to understand the different environmental conditions and the toxicity of G0 Transport.

【学位授予单位】：南京农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ127.11;X171.5

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