發(fā)布時間：2018-04-23 02:22

  本文選題：鉻 + 基因型差異　； 參考：《浙江大學》2015年博士論文

【摘要】：土壤重金屬污染是對人類健康構(gòu)成威脅的一個重要環(huán)境因素。煙草作為重要的經(jīng)濟作物,在葉片中能夠積累一定量的重金屬,危害人類健康。六大有毒的重金屬中,鉻(Cr)排第二位,主要通過人類活動被釋放到環(huán)境中。六價態(tài)鉻有毒且易誘變致癌,因此迫切需要闡明植物耐鉻機制,培育高耐鉻性但鉻低積累的煙草品種。本研究以耐鉻性不同煙草基因型為材料,旨在探討鉻脅迫對煙草生長與生理特性的影響及基因型差異,分離鑒定耐鉻相關(guān)的miRNAs和蛋白質(zhì)。主要研究結(jié)果如下： 1.鉻脅迫對煙草生長、礦質(zhì)元素含量、超微結(jié)構(gòu)和光合特性的影響及基因型差異 以兩個耐鉻性不同的煙草基因型貴煙1號(耐鉻基因型)和云煙2號(鉻敏感基因型)為材料,溫室水培鉻脅迫試驗,研究鉻脅迫對煙草植株生長、超微結(jié)構(gòu)、礦質(zhì)元素含量和光合特性的影響。結(jié)果表明,100μM鉻脅迫顯著抑制煙草植株的生長,降低株高、根長和生物量,其中鉻敏感基因型云煙2號比耐鉻基因型貴煙1號受抑制更嚴重。鉻脅迫降低葉片葉綠素含量、凈光合速率(Pn)和光系統(tǒng)Ⅱ的最大光化學效率(Fv/Fm)；同時,顯著減少根和葉片中的Zn含量以及根中的Fe和Mn含量,但提高葉片中的Fe含量。透射電子顯微鏡觀察結(jié)果表明貴煙1號比云煙2號受鉻脅迫的影響較小,貴煙1號葉片表現(xiàn)相對較好的光合器官組成結(jié)構(gòu)。 2.煙草根系中鉻脅迫響應niRNA和目標基因的全基因組鑒定 為了在整體水平上系統(tǒng)地分析鉻響應miRNA及其目標基因,以兩個耐鉻性不同的煙草基因型貴煙1號和云煙2號為材料,溫室水培鉻脅迫試驗,以無鉻基本培養(yǎng)液為對照,建立根系四個niRNA文庫：貴煙1號-鉻處理、貴煙1號-對照、云煙2號-鉻處理和云煙2號-對照。利用高通量測序技術(shù),鑒定得到53個保守的和29個新的miRNA家族。對41個保守的鉻響應miRNA家族進行比較基因組分析,結(jié)果表明11個miRNA家族在貴煙1號中上調(diào)但在云煙2號中不變,17個miRNA家族只在鉻脅迫下的云煙2號中上調(diào)。只有一個nmiRNA家族miR6149,在云煙2號中下調(diào)但在貴煙1號中不變。29個新的niRNA家族中,鉻脅迫下有14個在兩個基因型中差異表達。通過高通量降解組測序同源性搜索,對41個保守的和14個新的鉻響應miRNA家族的目標基因進行預測。COG功能類別分析結(jié)果表明一些預測的miRNA目標轉(zhuǎn)錄體對生物和非生物脅迫有響應。另外,通過RT-PCR驗證了部分鉻響應miRNA的表達模式。試驗結(jié)果為理解miRNA在鉻耐性中的功能提供了有價值的信息和框架。 3.鉻脅迫對煙草葉片蛋白表達譜的影響及基因型差異 利用比較蛋白質(zhì)組學技術(shù),探討了鉻脅迫對貴煙1號和云煙2號葉片蛋白質(zhì)表達譜的影響及基因型差異,與對照相比,100μM鉻脅迫下貴煙1號共有86/74個蛋白上調(diào)/下調(diào),云煙2號共有107/77個蛋白上調(diào)/下調(diào)。鑒定到12個耐鉻相關(guān)蛋白,100μM鉻脅迫下這些蛋白在貴煙1號中顯著表達但在云煙2號中下調(diào)或不變,或者在貴煙1號中不變但在云煙2號中下調(diào),上述耐性相關(guān)蛋白包括線粒體肽酶、脫水蛋白、超氧化物歧化酶、腺嘌呤轉(zhuǎn)磷酸核糖基酶和線粒體蘋果酸脫氫酶等；蛋白功能分類分別屬于脅迫響應、能量代謝、RNA結(jié)合和代謝相關(guān)蛋白。
[Abstract]:The heavy metal pollution in soil is an important environmental factor which threatens human health . As an important economic crop , it can accumulate a certain amount of heavy metals and harm human health . In six poisonous heavy metals , chromium ( Cr ) is released into the environment .

1 . Effects of chromium stress on tobacco growth , mineral element content , ultrastructure and photosynthetic characteristics and genotype difference

The effects of chromium stress on growth , ultrastructure , mineral element content and photosynthetic characteristics of tobacco plants were studied . The results showed that chromium stress inhibited the growth of tobacco plants , reduced plant height , root length and biomass .
At the same time , the content of Zn in roots and leaves and the content of Fe and Mn in roots were significantly reduced , but the content of Fe in the leaves was increased . The results of transmission electron microscopy showed that the effect of No . 1 was smaller than that of Yunyan No . 2 , and the leaves of Guido No . 1 showed relatively good composition structure of photosynthetic organs .

2 . Complete genome identification of the response of chromium stress response to niRNA and target gene in tobacco root system

In order to systematically analyze the chromium response miRNA and its target gene at the whole level , we identified four conservative and 29 new miRNA families by using high - throughput sequencing technology . The results showed that 11 miRNA families were up - regulated in Guiyan No . 1 , but there were 14 new miRNA families in Yunyan No . 1 .

3 . Effect of chromium stress on protein expression profile and genotype difference of tobacco leaf protein

The effects of chromium stress on the protein expression profile of No . 1 and Yunyan No . 2 leaves were investigated by comparative proteomic techniques . Compared with the control group , there were 86 / 74 proteins up - regulated / down - regulated under 100 渭M chromium stress , and there were 107 / 77 proteins up - regulated / down - regulated in Yunyan No . 2 .
Protein functional classification belongs to stress response , energy metabolism , RNA binding and metabolism - related proteins , respectively .

【學位授予單位】：浙江大學
【學位級別】：博士
【學位授予年份】：2015
【分類號】：S572

【參考文獻】

相關(guān)期刊論文 前2條

1 George P.COBB1,Todd A.ANDERSON;Identification and characterization of new plant microRNAs using EST analysis[J];Cell Research;2005年05期

2 ;Effects of Chronic Stress of Cadmium and Lead on Anatomical Structure of Tobacco Roots[J];Agricultural Sciences in China;2011年12期

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本文編號：1790023