本文選題：富氫水　切入點：紫花苜蓿　出處：《南京農(nóng)業(yè)大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：汞(Hg)是環(huán)境中有毒重金屬污染的主要來源之一,對植物細胞有很強的毒害作用。高等植物很容易積累汞,汞積累能夠誘導(dǎo)活性氧的爆發(fā),造成植物氧化脅迫傷害。最近研究表明氫氣(H2)是一種新的生物調(diào)節(jié)分子,參與植物的一系列生理活動。然而,我們還不清楚氫氣是否能夠調(diào)節(jié)植物對汞毒害的適應(yīng)能力。本文用富氫水(HRW)預(yù)處理研究了其對汞誘導(dǎo)的紫花苜蓿幼苗根部氧化傷害的緩解作用,闡述了氫氣在緩解汞毒害中的生理作用和相關(guān)的分子機理。研究結(jié)果表明:1.氯化汞(HgCl2)處理紫花苜蓿幼苗能誘導(dǎo)植物強烈的氧化傷害。不同濃度的HgCl2(1、10、100和500μM)處理,紫花苜蓿幼苗根部中TBARS含量呈現(xiàn)濃度依賴性;10 μMHgCl2處理與對照組相比TBARS含量增加了 91.6%,可以作為最適脅迫濃度;進一步研究發(fā)現(xiàn),不同濃度的HRW(1、10、50和100%)預(yù)處理能降低汞誘導(dǎo)的TBARS,其中,10%HRW預(yù)處理TBARS降低最顯著,可以作為后續(xù)研究最適的濃度。2.10%HRW預(yù)處理能夠緩解汞毒害引起的一些癥狀,包括改善幼苗的生長、緩解幼苗根部的生長抑制和提高幼苗的干重和鮮重。進一步研究發(fā)現(xiàn),10%HRW預(yù)處理后,紫花苜蓿幼苗根部汞的積累明顯下降。組織學(xué)染色的結(jié)果表明,與對照相比,汞處理誘導(dǎo)大量ROS的產(chǎn)生,10%HRW預(yù)處理能夠緩解汞誘導(dǎo)的氧化傷害。3.汞誘導(dǎo)的超氧化物歧化酶(SOD)活性以及其同工酶活性的增加能夠顯著的被10%HRW逆轉(zhuǎn)。進一步的研究表明,10%HRW能夠在酶水平和轉(zhuǎn)錄水平上提高兩種過氧化氫清除酶一愈創(chuàng)木酚過氧化物酶(POD)和抗壞血酸過氧化物酶(APX)的活性和轉(zhuǎn)錄本。同時,還原型與氧化型谷胱甘肽(GSH)比值、同源型谷胱甘肽(hGSH)含量、抗壞血酸(AsA)含量以及相關(guān)基因表達也呈現(xiàn)顯著增加的趨勢,上述與HRW緩解紫花苜蓿幼苗根部氧化性損傷的結(jié)果是一致的�？傊�,上述研究結(jié)果表明,HRW能緩解汞脅迫引起毒害,上述效應(yīng)可能與緩解紫花苜蓿幼苗根部生長的抑制以及汞的積累,延緩氧化脅迫和重建氧化還原穩(wěn)態(tài)等有關(guān)。
[Abstract]:HG) is one of the main sources of toxic heavy metal pollution in the environment, and has a strong toxic effect on plant cells. Higher plants can easily accumulate mercury, mercury accumulation can induce the outbreak of reactive oxygen species. Recent studies have shown that H _ 2H _ 2) is a new biological regulatory molecule involved in a series of physiological activities in plants. It is not clear whether hydrogen can regulate the adaptability of plants to mercury toxicity. In this paper, the effects of hydrogen on oxidative damage induced by mercury in alfalfa seedlings were studied by hydrogen rich water (HRW) pretreatment. The physiological function and molecular mechanism of hydrogen in mitigating mercury toxicity were described. The results showed that the treatment of HgCl2) could induce strong oxidative damage in alfalfa seedlings. Different concentrations of HgCl2HgCl2 (100 渭 M and 500 渭 M) could induce oxidative damage in alfalfa seedlings. The concentration of TBARS in the roots of alfalfa seedlings showed a concentration dependence of 10 渭 MHgCl2. Compared with the control group, the content of TBARS increased by 91.6 渭 MHgCl2, which could be regarded as the optimal stress concentration. Pretreatment with different concentrations of HRW can reduce the mercury induced TBA, and the TBARS of 10 HRW pretreatment is the most significant, which can be used as the best concentration in the follow-up study to alleviate some symptoms caused by mercury toxicity, including improving seedling growth. It was found that the accumulation of mercury in the roots of alfalfa seedlings decreased significantly after pretreatment with 10 HRW. The results of histological staining showed that the results of histological staining showed that the content of mercury in the roots of alfalfa seedlings was significantly lower than that of the control. Mercury treatment induced a large number of ROS production. The pretreatment of 10 HRW alleviated the oxidative injury induced by mercury. The increase of mercury-induced superoxide dismutase (SOD) activity and its isozyme activity could be significantly reversed by 10HRW. The further study shows that the increase of mercury-induced superoxide dismutase (SOD) activity can be reversed by 10HRW. The HRW can increase the activity and transcripts of two hydrogen peroxide scavenger enzymes, guaiacol peroxidase (POD) and ascorbic acid peroxidase (APX), at both the enzyme level and the transcriptional level. The ratio of reductive to oxidized glutathione (GSH), homologous glutathione hGSH, ascorbic acid ascorbic acid (ascorbic acid) and related gene expression also increased significantly. These results are consistent with the results of HRW in alleviating oxidative damage in alfalfa seedlings. These effects may be related to alleviating the inhibition of root growth and accumulation of mercury, delaying oxidative stress and reconstructing redox homeostasis of alfalfa seedlings.
【學(xué)位授予單位】：南京農(nóng)業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：X171.5;S541.9

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1 方鵬;富氫水（HRW）對汞誘導(dǎo)的紫花苜蓿幼苗根部氧化傷害的緩解作用[D];南京農(nóng)業(yè)大學(xué);2015年

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本文編號：1559264