三七对重金属镉的富集效应及其生理机制研究

发布时间：2018-05-14 04:26

本文选题：镉富集 + 三七　；参考：《昆明理工大学》2017年硕士论文

【摘要】：三七[Panax notoginseng(Burk.)F.H.Chen]为五加科人参属多年生草本植物,常以其干燥块根入药,近年来其茎叶作为新资源食品被开发利用,其传统药效有止血、活血、散瘀、定痛、降压、降脂、降血糖等。云南省是三七的道地产区,中国市场中95%的三七来自云南。同时,云南也是矿产大省,其丰富的矿产资源造成了土壤中重金属含量较高,尤其是作为镉出产全国第一的地区,其土壤中的镉背景值应被重视。近年来,食品镉污染问题频发,药材镉安全也成为中药材市场关注的重点。如何在高镉背景值下种植三七,三七对镉是否存在富集效应,镉是否影响三七生长发育及药材质量,三七对镉的吸收与贮存途径如何,均需要研究来阐明。因此,本文以三七为研究对象,通过土培,水培等实验,以期探明三七对镉富集的生理响应及其吸收镉的生理机制。本文的主要研究成果如下:1.以二年生三七为实验材料,通过土培实验研究了不同浓度镉处理(0、5、10、30、60 mg·kg~(-1))对三七生长发育及皂苷积累的影响,同时用Tessier A连续提取法对三七种植土壤中的镉进行了分类。结果表明,三七种植土壤中五种土壤镉形态的大小顺序为:碳酸盐结合态残留态铁锰氧化物结合态有机物结合态可交换态,通过潜在生态危害指数评价法得出土壤中镉含量的生态环境危害风险低。5 mg·kg~(-1)镉处理可显著促进三七生长,10～60 mg·kg~(-1)镉处理下的三七各农艺性状显著低于空白处理组;5 mg·kg~(-1)镉处理可增加三七对N、P、K的吸收积累,高浓度镉则抑制其累积;三七各部位镉含量分别与镉处理时间和浓度呈正相关,各部位镉含量大小顺序为:须根剪口主根叶茎花;各部位镉富集系数随处理时间延长而增大,但随处理浓度的升高而下降;镉处理使三七中五种主要皂苷成分:R1,Rg1,Re,Rb1,Rd及其总和均低于空白组。综上所述,低浓度镉处理可刺激三七生长,高浓度镉则对三七生长产生抑制,镉胁迫会降低三七主要药效成分皂苷的积累,说明镉会影响三七药材质量,应减少种植背景中的镉含量,以保证三七药材的安全与质量。2.以二年生三七为试验材料,在水培条件下研究了镉胁迫(0、2.5、5、10μmol·L~(-1))对三七抗氧化酶系统和光合参数的影响及三七对镉的吸收分配规律。结果表明:2.5μmol·L~(-1)镉处理可诱导SOD、POD、APX等酶活性的升高,10 μmol·L~(-1)镉处理则对SOD、POD、APX和CAT均产生抑制作用;镉处理对三七各部位CAT活性均具有抑制作用;三七净光合速率、蒸腾速率、气孔导度均随镉处理浓度的升高而降低,胞间CO2浓度则呈先下降后上升的趋势;三七各器官镉含量表现为须根剪口主根叶片茎;叶、茎、剪口、须根、主根镉富集系数均随镉处理浓度的升高而降低;各器官中镉含量与迁移系数均随镉处理浓度的升高而上升。综上所述,镉胁迫可对三七抗氧化酶系统和光合系统产生影响,三七对镉具有富集作用,应合理选择三七种植基地以减少对镉的吸收,合理选取三七入药部位,以降低镉摄入风险。3.以二年生三七为试验材料,通过水培试验研究了三七对镉的吸收方式、运输动力、时间吸收动力学及浓度动力学特征。结果表明:抑制代谢与抑制蒸腾均能减少三七对镉的吸收与转运,说明三七对镉的吸收与转运兼备主动与被动;试验初期的0～2小时为三七快速吸收镉的时期,2小时后三七对镉的吸收速率逐渐下降,24小时后趋于平缓;三七对镉的吸收随镉处理浓度升高而增加,本试验中的20 μml·L~(-1)处理浓度并非三七吸收镉的阈值。4.以二年生三七为材料,研究了水培条件下外源一氧化氮(NO)供体硝普钠(SNP)和清除剂2-4-羧苯基四甲基咪唑烷~(-1)-氧-3-氧化物(L-NAME)处理对镉胁迫下三七的生理及镉积累特性的影响。结果表明:50 μmol·L~(-1) SNP处理可降低镉胁迫下(10 μmol·L~(-1))三七中超氧阴离子O~2·、产生速率及丙二醛含量;提高三七各部位(叶、茎、剪口、根)的SOD、POD及CAT活性;促进镉胁迫下三七叶片光合效率及叶绿素含量的上升。但高浓度SNP处理(100μmol·L~(-1))对上述指标具有负调控作用。SNP处理能促进三七各部位镉含量和富集系数的升高,且随处理浓度的升高而增强,但SNP对镉转移系数无显著影响。L-NAME处理显著提升镉胁迫下三七中超氧阴离子02·-产生速率及丙二醛含量;降低各部位的抗氧化酶活性;同时也减少了镉在各部位的累积;上述作用效应随L-NAME处理浓度的升高而增强。综上所述,NO信号参与调控镉胁迫下三七抗氧化酶系统、光合系统及对镉的吸收贮存。
[Abstract]:37 [Panax notoginseng (Burk.) F.H.Chen] is a perennial herb of Radix Acanthopanax. It is often used as a perennial herb of Radix Acanthopanax. In recent years, its stem and leaf have been developed and utilized as a new resource food. Its traditional efficacy has hemostatic, blood circulation, stasis, pain, blood pressure, blood fat, blood sugar and so on. Yunnan is a 37 real estate area, and 95% of the Chinese market is three. Seven is from Yunnan. At the same time, Yunnan is also a major mineral province. Its rich mineral resources have caused high heavy metal content in the soil, especially as the first area of cadmium production nationwide. The background value of cadmium in the soil should be paid attention to. In recent years, the problem of cadmium pollution in food is frequent and the safety of medicinal materials and cadmium has become the focus of the Chinese medicinal materials market. Under high cadmium background, it is necessary to study whether cadmium has a enrichment effect on cadmium, whether cadmium has a enrichment effect on cadmium, whether cadmium affects 37 growth and quality of medicinal materials, and how the absorption and storage of cadmium is 37. Therefore, this paper uses 37 as the research object, through soil culture and hydroponics, in order to explore the physiological response of 37 cadmium enrichment. The main research results in this paper are as follows: 1. the effects of different concentrations of cadmium treatment (0,5,10,30,60 mg. Kg~ (-1)) on the growth and the accumulation of saponins were studied by soil culture experiment, and the cadmium in 37 cultivated soils was divided by Tessier A continuous extraction. The results showed that the order of cadmium morphology in the five soils of 37 cultivated soils was the exchangeable state of the combined state of Fe Mn oxide bound organic compounds in the carbonate bound state, and the ecological environment of cadmium content in the soil through the potential ecological hazard index evaluation method was harmful to the risk of low.5 mg. Kg~ (-1) cadmium treatment, which could significantly promote 37. Growth, 10~60 mg. Kg~ (-1) cadmium treatment of 37 agronomic characters significantly lower than the blank treatment group, 5 mg. Kg~ (-1) cadmium treatment can increase 37 pairs of N, P, K absorption accumulation, high concentration of cadmium inhibits the accumulation of cadmium, the cadmium content of 37 parts is positively correlated with the time and concentration of cadmium treatment, the order of cadmium content in each part is the shear mouth of fibrous root The cadmium enrichment coefficient of the main root leaves increased with the treatment time, but decreased with the increase of treatment concentration. The cadmium treatment made the five main saponins in 37: R1, Rg1, Re, Rb1, and Rd were lower than those in the blank group. In conclusion, low concentration cadmium treatment could stimulate 37 growth and high concentration of cadmium inhibited the growth of 37. Cadmium stress can reduce the accumulation of 37 main effective component saponins, indicating that cadmium affects the quality of 37 medicinal materials and should reduce the content of cadmium in the planting background, in order to ensure the safety and quality of the 37 medicinal materials.2. with the biennial 37 as the experimental material. Under the hydroponic condition, the cadmium stress (0,2.5,5,10 Mu mol. L~ (-1)) and the 37 antioxidant enzyme system are studied. The effect of photosynthetic parameters and the absorption and distribution of 37 cadmium showed that 2.5 mol. L~ (-1) cadmium treatment could induce the increase of SOD, POD, APX and other enzyme activities, and 10 u mol. L~ (-1) cadmium treatment had inhibitory effect on SOD, POD, APX, and SOD; 37 net photosynthetic rate, transpiration rate The rate of stomatal conductance decreased with the increase of cadmium concentration, and the concentration of intercellular CO2 decreased first and then increased. 37 the cadmium content in each organ was shown as the stem of the main root of the fibrous root shear. The cadmium enrichment coefficient of the leaves, stems, shears, fibrous roots and main roots decreased with the increase of cadmium concentration, and the cadmium content and migration coefficient in each organ were all along with cadmium. In summary, cadmium stress can affect the 37 antioxidant enzyme system and photosynthetic system. 37 cadmium has a enrichment effect. 37 planting bases should be selected to reduce the absorption of cadmium, and 37 drug sites should be selected to reduce the risk of cadmium uptake by.3. with a biennial 37 as experimental material and through water. 37 pairs of cadmium absorption, transport dynamics, time absorption kinetics and concentration kinetics were studied. The results showed that inhibition of metabolism and inhibition of transpiration could reduce the absorption and transport of cadmium by 37, indicating that 37 cadmium absorption and transport were both active and passive; 0~2 hours at the early stage of the experiment were 37 fast absorption of cadmium. During the period, the absorption rate of cadmium decreased gradually after 2 hours, and then slowed down after 24 hours, and the absorption of cadmium increased with the increase of cadmium concentration. The concentration of 20 mu ml. L~ (-1) in this experiment was not 37 of the threshold.4. of cadmium absorption by 37 year 37 as the material. The nitrate (NO) donor nitrate (NO) donor was studied under hydroponic condition. The effects of sodium (SNP) and scavenger 2-4- carboxybenzyl four methyl imidazonyl ~ (-1) - oxygen -3- oxide (L-NAME) on the physiological and cadmium accumulation of 37 under cadmium stress. The results showed that 50 u mol. L~ (-1) SNP treatment could reduce the superoxide anion, production rate and malondialdehyde content under Cadmium stress (10 mu mol. L~ (-1)) 37; increase 37 The activity of SOD, POD and CAT in the parts (leaves, stems, scissors, roots), promoted the increase of photosynthetic efficiency and chlorophyll content of 37 leaves under cadmium stress. But high concentration SNP treatment (100 mu mol. L~ (-1)) had negative regulation on the above indexes,.SNP treatment could promote the increase of cadmium content and enrichment coefficient of 37 parts, and increased with the increase of treatment concentration. However, SNP had no significant effect on the transfer coefficient of cadmium..L-NAME treatment significantly enhanced the 02. - production rate of superoxide anion and the content of malondialdehyde in 37 of cadmium stress, reduced the activity of antioxidant enzymes in various parts, and reduced the accumulation of cadmium in each part; the effect effect was enhanced with the increase of the concentration of L-NAME treatment. In summary, NO signal reference And regulation of 37 antioxidant enzyme systems, photosynthetic system and cadmium uptake and storage under cadmium stress.

【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X173;S567.236

【参考文献】