本文選題：苧麻 + 鎘��； 參考：《湖南大學(xué)》2015年碩士論文

【摘要】：本研究采用素有“中國草”之稱的中國特有的以紡織為主要用途的作物——苧麻作為實驗選材,重金屬鎘(Cd)為目標污染物,研究外源鈣(Ca)和亞精胺(Spd)對鎘脅迫下苧麻幼苗生長、光合作用、抗氧化作用及Cd吸收轉(zhuǎn)運的影響,探索外源物質(zhì)對苧麻修復(fù)鎘污染影響的作用機理。實驗結(jié)果表明:5 mg/L Cd處理下,苧麻根莖葉中Cd濃度分別為309.67 mg/kg、117.08 mg/kg、87.72 mg/kg,這表明苧麻對Cd有一定程度的富集能力,可用于重金屬Cd污染的植物修復(fù)。但Cd處理下苧麻生物量、可溶性蛋白、葉綠素含量等都顯著降低,而脯氨酸、過氧化氫、丙二醛含量大幅增加,抗氧化物酶(SOD、CAT、POD、APX)活性及抗氧化物質(zhì)(GSH、維生素E)水平等均發(fā)生變化,說明Cd脅迫通過影響植物生長發(fā)育、光合作用、生理代謝、氧化程度等對苧麻產(chǎn)生了毒害作用。外源Ca對苧麻重金屬Cd吸收及轉(zhuǎn)運的影響很大:所有濃度的Ca處理都增加了Cd從苧麻根部到地上部分的轉(zhuǎn)運能力。特別是低濃度Ca(1 mmol/L)處理,其在提高Cd的轉(zhuǎn)運系數(shù)(TF1)的同時還大幅增加了苧麻莖和葉對重金屬Cd的吸收,使得苧麻地上部分積累的重金屬Cd濃度超過100 mg/kg DW。不同濃度外源Ca對Cd脅迫下植物生理指標的影響存在差異:中濃度Ca(5 mmol/L)處理增加了苧麻生物量、可溶性蛋白濃度、植物體內(nèi)葉綠素含量,降低了重金屬Cd的積累和脯氨酸水平,該濃度Ca處理通過調(diào)節(jié)上述生理指標起到了緩解Cd毒害的作用;而低濃度Ca(1 mmol/L)處理則通過增加重金屬Cd的積累及脯氨酸水平,降低苧麻地上部分及地下部分生物量和可溶性蛋白質(zhì)含量加劇了Cd的毒害作用;高濃度Ca(10 mmol/L)處理則通過降低可溶性蛋白的含量,表現(xiàn)出一定程度的毒害作用。Spd與Ca的聯(lián)用效果因Ca濃度不同產(chǎn)生不同的結(jié)果:與1 mmol/L Ca+Cd處理相比,Spd可顯著增加苧麻根莖葉的生物量。在植物抗氧化脅迫方面,Spd的添加可通過降低MDA及H2O2濃度,調(diào)節(jié)抗氧化物酶SOD、CAT、POD、AP X等的活性,提高抗氧化物質(zhì)GSH、維生素E的水平等緩解由1 mmol/L Ca+Cd處理對苧麻造成的氧化脅迫作用。但5 mmol/L Ca+Cd處理下Spd的緩解作用則不明顯。綜上所述,Cd脅迫嚴重影響了苧麻的生長及生理代謝,5 mmol/L Ca處理可緩解Cd的毒害作用;外源1 mmol/L Ca處理可增加苧麻對Cd的吸收及轉(zhuǎn)運但會加劇Cd的毒害作用;Spd與1 mmol/L Ca聯(lián)用,則可在增加苧麻對重金屬吸收及轉(zhuǎn)運水平的基礎(chǔ)上緩解Cd對植物產(chǎn)生的毒害作用。
[Abstract]:In this study, the growth of Ramie seedlings under cadmium stress was studied by using Chinese unique crop-Ramie, which is known as "Chinese grass" and heavy metal cadmium and cadmium (CD) as the target pollutant, to study the effects of exogenous Ca) and spermidine (Spd) on the growth of Ramie seedlings under cadmium stress. The effects of photosynthesis, antioxidation and CD absorption and transport on the effects of exogenous substances on the remediation of cadmium pollution in Ramie were explored. The results showed that the CD concentrations in Ramie roots and leaves were 309.67 mg / kg, 117.08 mg / kg, 87.72 mg / kg, respectively, which indicated that Ramie had a certain degree of CD enrichment ability and could be used for the phytoremediation of heavy metal CD pollution. However, the biomass, soluble protein and chlorophyll content of Ramie decreased significantly under CD treatment, while the contents of proline, hydrogen peroxide and malondialdehyde increased significantly, and the activities of antioxidant enzyme SODCAT PODX (APX) and the level of antioxidant substances (GSH, vitamin E) were all changed. CD stress had toxic effects on Ramie by affecting plant growth and development, photosynthesis, physiological metabolism and degree of oxidation. The effect of exogenous Ca on the absorption and transport of heavy metal CD in Ramie was very great: all the Ca treatments increased the transport ability of CD from Ramie roots to aboveground parts. Especially, the low concentration of Ca(1 mmol / L increased CD transport coefficient (TF1) and significantly increased the uptake of heavy metal CD in Ramie stems and leaves, which led to the accumulation of CD in Ramie aerial parts over 100 mg/kg DW. The effects of exogenous Ca at different concentrations on plant physiological indexes under CD stress were different: middle concentration of Ca(5 mmol / L increased Ramie biomass, soluble protein concentration, chlorophyll content, CD accumulation and proline level. This concentration of Ca could alleviate CD toxicity by regulating the physiological indexes mentioned above, while the low concentration of Ca(1 mmol / L could increase the accumulation of heavy metal CD and proline level. The reduction of biomass and soluble protein content in aboveground and underground parts of Ramie increased the toxicity of CD, while the high concentration of Ca(10 mmol / L decreased the content of soluble protein. Compared with 1 mmol/L Ca CD treatment, SPD could significantly increase the biomass of Ramie rhizomes and leaves. In the aspect of plant antioxidant stress, the addition of SPD could reduce the concentration of MDA and H2O2, regulate the activity of antioxidant enzyme SODCATCATPODX, and increase the level of antioxidants GSH and vitamin E to alleviate the oxidative stress caused by 1 mmol/L Ca CD treatment on Ramie. However, the response of Spd to 5 mmol/L Ca CD treatment was not obvious. In conclusion, CD stress seriously affected the growth and physiological metabolism of Ramie treated with 5 mmol/L Ca, and exogenous 1 mmol/L Ca treatment could increase the CD uptake and transport of Ramie, but increase the toxic effect of CD in combination of SPD and 1 mmol/L Ca. On the basis of increasing the heavy metal uptake and transport level of Ramie, the toxic effect of CD on plants was alleviated.
【學(xué)位授予單位】：湖南大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：X503.231

【參考文獻】

相關(guān)期刊論文 前10條

1 王艷娜;;土壤重金屬污染現(xiàn)狀與防治方法[J];價值工程;2014年35期

2 王春林;劉云國;曾光明;胡新將;尹怡誠;胡熙;周璐;王亞琴;李華英;;外源硒對苧麻的鎘脅迫毒性的緩解機制(英文)[J];Transactions of Nonferrous Metals Society of China;2014年12期

3 Huaying Li;Yunguo Liu;Guangming Zeng;Lu Zhou;Xin Wang;Yaqin Wang;Chunlin Wang;Xinjiang Hu;Weihua Xu;;Enhanced efficiency of cadmium removal by Boehmeria nivea(L.) Gaud. in the presence of exogenous citric and oxalic acids[J];Journal of Environmental Sciences;2014年12期

4 蒲晨新;余淵;孫大江;;土壤重金屬污染現(xiàn)狀與植物修復(fù)研究[J];四川環(huán)境;2014年05期

5 凌楓;;土壤重金屬污染現(xiàn)狀及治理[J];科技致富向?qū)?2014年29期

6 田宇哲;王瑩;王銳;關(guān)e，

本文編號：1974614