【摘要】：由于多環(huán)芳烴在環(huán)境中的高殘留、可在植物體內(nèi)積累并能通過食物鏈進(jìn)入人體,因此研究者對多環(huán)芳烴在土壤-植物系統(tǒng)中的遷移過程給予了很大的關(guān)注。植物吸收運(yùn)輸多環(huán)芳烴的過程與機(jī)制研究對于農(nóng)產(chǎn)品的安全生產(chǎn)和污染土壤的植物修復(fù)至關(guān)重要,然而迄今尚未見有關(guān)于多環(huán)芳烴在植物根系內(nèi)的短距離運(yùn)輸和由根部向地上部的長距離運(yùn)輸過程的報(bào)道。為此,本文通過水培實(shí)驗(yàn),對植物根系質(zhì)外體溶液的提取方法進(jìn)行了探索,對植物根系質(zhì)外體和共質(zhì)體多環(huán)芳烴吸收特征差異進(jìn)行了分析,同時(shí)研究了植物根系吸收多環(huán)芳烴后莖部傷流液成分的變化,最后探討了植物根系質(zhì)外體和共質(zhì)體多環(huán)芳烴吸收運(yùn)移的影響因素。論文主要結(jié)論如下:植物根系質(zhì)外體溶液的提取方法研究結(jié)果表明,小麥根系質(zhì)外體菲提取量隨真空度、真空時(shí)間、離心力與離心時(shí)間的增加而增大;在一定范圍內(nèi),小麥根系質(zhì)外體內(nèi)六磷酸葡萄糖脫氫酶的活性隨各因素的增加而升高。依據(jù)質(zhì)外體溶液受原生質(zhì)污染程度小于1%且盡量提取完全的原則下,真空滲透離心提取法的最佳真空度為70 kPa,最佳真空時(shí)間為10 min,最佳離心速率為3068 r·min-1,最佳離心時(shí)間為15 min。在一定的時(shí)間范圍內(nèi),不同溫度處理小麥根系質(zhì)外體和共質(zhì)體菲吸收量隨提取時(shí)間的延長而增加,隨營養(yǎng)液中菲的濃度的增大而增加。在不同溫度處理中,35℃處理小麥根系質(zhì)外體和共質(zhì)體菲吸收量最大。在相同溫度條件下,小麥根系質(zhì)外體與共質(zhì)體對菲的吸收存在顯著性差異,共質(zhì)體對菲的吸收量高于質(zhì)外體部分。由小麥根系質(zhì)外體和共質(zhì)體菲吸收的動(dòng)力學(xué)和熱力學(xué)可知,溫度越高,反應(yīng)速率常數(shù)越大,小麥根系質(zhì)外體和共質(zhì)體菲吸收的活化能都為正值,且共質(zhì)體活化能小于質(zhì)外體,因此共質(zhì)體菲吸收易于質(zhì)外體。傷流液組分分析表明,玉米傷流液中菲高于小麥傷流液,且存在顯著性差異CP0.05)。菲處理降低了玉米和小麥植株的傷流液強(qiáng)度,玉米和小麥菲處理后傷流液中有機(jī)物質(zhì)可溶性蛋白含量明顯升高(P0.05),玉米甲酸增加顯著,小麥甲酸增加不顯著,但銨態(tài)氮、鉀、有效磷及pH顯著下降(P0.05)。由此推測,多環(huán)芳烴在植物體內(nèi)的長距離運(yùn)輸與可溶性蛋白關(guān)系密切,并且對植物營養(yǎng)物質(zhì)的運(yùn)輸有抑制作用。植物根系質(zhì)外體和共質(zhì)體多環(huán)芳烴吸收的影響因素研究表明,黑暗與根系地上部剪切處理能夠降低小麥根系質(zhì)外體的菲吸收。25℃處理小麥根系共質(zhì)體的菲吸收顯著高于4 ℃處理,抑制劑2,4-DNP和釩酸鈉抑制了小麥根系共質(zhì)體的菲吸收。
[Abstract]:Due to the high residue of PAHs in the environment, PAHs can accumulate in plants and enter the human body through the food chain. Therefore, researchers have paid great attention to the migration of PAHs in soil-plant systems. Studies on the processes and mechanisms of plant uptake and transport of polycyclic aromatic hydrocarbons (PAHs) are essential for the safe production of agricultural products and the phytoremediation of contaminated soils. However, there are no reports on the short distance transport of PAHs in plant roots and the long distance transport from root to ground. In this paper, the extraction method of extracellular solution from plant root system was explored by hydroponic experiment, and the differences of the absorption characteristics of polycyclic aromatic hydrocarbons (PAHs) between the plant root system and the plant root system were analyzed. At the same time, the changes of the components of the stem effluents after the plant roots absorbed polycyclic aromatic hydrocarbons (PAHs) were studied. Finally, the factors affecting the absorption and migration of PAHs in the plant roots were discussed. The main conclusions of this paper are as follows: the results of extraction method of plant root exophyte showed that the amount of phenanthrene extracted from wheat root system increased with the increase of vacuum, vacuum time, centrifugal force and centrifugal time, and within a certain range, the extraction amount of phenanthrene from wheat root system increased with the increase of vacuum, vacuum time, centrifugal force and centrifugal time. The activity of glucose-hexaphosphate dehydrogenase in wheat roots increased with the increase of various factors. According to the principle that the degree of protoplast contamination is less than 1% and the extraction is as complete as possible, the optimum vacuum degree is 70 kPa, the optimum vacuum time is 10 min, the optimal centrifugation rate is 3068 r min-1, the optimum centrifugal time is 15 min.. In a certain time range, the phenanthrene absorption of wheat root and synplast increased with the increase of extraction time and the concentration of phenanthrene in the nutrient solution. The phenanthrene absorption of wheat root at 35 鈩，

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