本文選題：光照 + 煙草�。� 參考：《東北林業(yè)大學》2016年博士論文

【摘要】：煙草野火病是由煙草野火病菌(Pseudomonas syringae pv. tabaci, Pst)引起的流行性細菌病害,對煙葉產量和品質均有顯著負影響。近年來,野火病菌侵染及植物防御機制成為相關研究的熱點問題。植物的光合作用和呼吸作用是植物物質和能量的來源,在植物抗病響應過程中具有重要作用,因此是許多病原微生物的主要攻擊目標。然而野火病菌對煙草葉片光合和呼吸作用的影響及其機理尚不清楚。本研究在光照(200μmol m-2s-1)或黑暗條件下,人工注射野火病菌懸液(106)對煙草葉片接種,通過葉綠素熒光快速誘導動力學曲線分析、膜蛋白Western blot分析等方法,探討野火病菌侵染后對煙草葉片光系統(tǒng)Ⅱ (Photosystem Ⅱ, PSII)和光系統(tǒng)I(Photosystem Ⅰ, PSI)產生的影響,闡明光照條件下野火病菌對煙草葉片光合機構產生較輕傷害的機理。同時為了排除葉綠體和菌本身呼吸的影響,采用沒有功能性葉綠體的煙草BY-2懸浮細胞系和含有野火粗毒素的野火病菌代謝產物(Pst ext)來探討野火病菌對煙草呼吸途徑的影響。研究野火病菌對煙草光系統(tǒng)和呼吸電子傳遞鏈的影響不僅有助于闡明煙草-野火病菌相互作用的機制,還可以從生理角度加深人們對野火病害的理解,為煙草抗性育種和基因改良提供理論依據(jù)。實驗結果顯示：(1)野火病菌侵染3d后,葉片內葉綠素含量顯著下降,葉片注射區(qū)域出現(xiàn)萎黃病變,呈現(xiàn)野火病特征,在黑暗條件下病變更嚴重；(2)野火病菌侵染3d后,K點和J點的相對可變熒光Wk和VJ逐漸增大,葉片最大光化學效率(Fv/Fm)和單位面積有活性反應中心的數(shù)目(RC/CSm)均顯著下降,放氧復合體(Oxygen evolving complex, OEC)的核心組分PsaO、PSII反應中心核心蛋白D1以及PSI核心組分PsaA均發(fā)生明顯的降解,PSI活性顯著下降,在黑暗條件下變化幅度更大；(3)野火病菌侵染3d后,煙草葉片內病原菌數(shù)量顯著增加,黑暗下葉片內野火病菌的數(shù)目是光照下的17倍,煙草葉片H2O2含量明顯升高,光照條件下升高比例更大;(4)在黑暗條件下,侵染之前用H2O2預處理,3d后煙草葉片萎黃病變減輕,葉片內病原菌數(shù)目降低；在光照條件下,侵染之前用甲基紫精(Methyl viologen, MV)預處理,3d后煙草葉片萎黃病變減輕,葉片內病原菌數(shù)目降低；侵染之前用敵草隆(3-(3,4-dichloropheny1)-1,1-dimethylurea, DCMU)預處理,3d后煙草葉片萎黃病變加重,同時葉片內病原菌數(shù)目增加；(5)野火病菌代謝物處理后,煙草BY-2細胞內出現(xiàn)非光合電子傳遞鏈介導的活性氧(Reactive oxygen species, ROS)積累、細胞總呼吸降低、交替氧化酶呼吸途徑(Alternative respiration pathtway, AOX)在總呼吸中所占比例增加,胞內ATP含量降低。綜上所述,本研究結果表明野火病菌侵染后,在光照和黑暗條件下光合電子傳遞鏈QA到QB電子傳遞受到限制,OEC受到傷害,煙草葉片PSII供體側、受體側、反應中心的數(shù)目和活性均受到傷害,煙草葉片PSI和PSII發(fā)生光抑制或光抑制類似的傷害,且在黑暗條件下對光系統(tǒng)的傷害更為嚴重；煙草葉片的萎黃病變癥狀以及葉片內部野火病菌的數(shù)目均與H202積累負相關,光可以通過H202的積累來抑制野火病菌侵染后煙草葉片內病原菌的數(shù)目,這可能是光照條件下野火病菌導致煙草光系統(tǒng)出現(xiàn)較輕傷害的原因之一。
[Abstract]:Tobacco wildfire is a popular bacterial disease caused by Pseudomonas syringae pv. tabaci (Pst) and has a significant negative effect on the yield and quality of tobacco leaves. In recent years, the infection of wildfire pathogen and plant defense mechanism have become a hot issue in the related research. Plant photosynthesis and respiration are plant material and energy. The source, which plays an important role in the process of plant disease resistance and response, is the main target for many pathogenic microorganisms. However, the effect and mechanism of wildfire pathogen on Photosynthesis and respiration of tobacco leaves are not clear. In this study, under the light (200 mu m-2s-1) or dark strips, the artificial injection of wildfire pathogen suspension (106) to tobacco The effects of wild fire pathogen on the production of light system II (Photosystem II, PSII) and I (Photosystem I, PSI) of tobacco leaves after the infection of wildfire pathogens were investigated by the method of chlorophyll fluorescence rapid induction kinetic curve analysis and membrane protein Western blot analysis. The photosynthetic mechanism of tobacco leaves under light conditions was elucidated. At the same time, in order to eliminate the effects of the chloroplast and the respiration of the bacteria itself, the effect of wildfire pathogen on the respiration pathway of tobacco was explored by using the BY-2 suspension cell line without functional chloroplasts and the metabolite of wildfire pathogen containing wildfire crude toxin (Pst ext). The effect of the transfer chain not only helps to elucidate the mechanism of the interaction between tobacco and wildfire pathogens, but also can deepen people's understanding of Wildfire Disease from the physiological point of view, and provide theoretical basis for tobacco resistance breeding and gene improvement. The experimental results show: (1) after the infection of 3D, the content of chlorophyll in leaves is significantly decreased and the injection area of leaves is injected. The region appeared yellow disease and showed the characteristics of wildfire, and the disease changed seriously under the dark condition. (2) after the infection of 3D, the relative variable fluorescence Wk and VJ of K point and J point increased gradually, and the maximum photochemical efficiency (Fv/Fm) and the number of active reaction centers (RC/CSm) in the unit area decreased significantly, and the oxygen complex (Oxygen evolving compl). The core components of ex, OEC, PsaO, the core protein D1 of the PSII reaction center and the PSI core component PsaA were degraded obviously, the activity of PSI decreased significantly, and the change amplitude was greater in the dark conditions. (3) the number of pathogens in tobacco leaves increased significantly, and the number of wildfire pathogens in the dark leaves was 17 times that of light under the darkness. The content of H2O2 in tobacco leaves increased significantly and increased significantly under light conditions. (4) under the dark conditions, H2O2 pretreatment was used before the infection. After 3D, the yellowish disease of tobacco leaves was reduced and the number of pathogenic bacteria in the leaves decreased. Under the light conditions, pre treatment was pretreated with methyl violet (Methyl viologen, MV), and the degeneration of tobacco leaves was reduced after 3D. The number of pathogenic bacteria in the leaves was reduced, and pretreated with diuron (3- (3,4-dichloropheny1) -1,1-dimethylurea, DCMU) before the infection, after 3D, the leaf yellow disease of tobacco leaves increased, and the number of pathogenic bacteria in the leaves increased. (5) after the metabolite of wildfire pathogen, the non photosynthetic electron transfer chain mediated reactive oxygen species (Reac) appeared in the BY-2 cells of the wild fire pathogen (Reac). Tive oxygen species, ROS) accumulated, total cell respiration decreased, and the proportion of alternate oxidase respiration pathway (Alternative respiration pathtway, AOX) increased in total respiration and decreased intracellular ATP content. In summary, the results of this study showed that after the infection of wildfire bacteria, the electron transfer chain of the photosynthetic electron transfer chain was carried out in light and dark conditions, and QA to QB electron transfer. Restricted, OEC was injured, the PSII donor side of tobacco leaves, the receptor side, the number and activity of the reaction center were injured, the tobacco leaves PSI and PSII had photoinhibition or photoinhibition similar damage, and the damage to the light system was more severe in the dark conditions; the yellow disease symptoms of tobacco leaves and the internal wildfire pathogens in leaf blades. The number of H202 accumulation was negatively correlated with the accumulation of H202, which could inhibit the number of pathogenic bacteria in tobacco leaves after the infection of wildfire pathogen, which may be one of the reasons for light damage caused by wildfire pathogen in light conditions.
【學位授予單位】：東北林業(yè)大學
【學位級別】：博士
【學位授予年份】：2016
【分類號】：S435.72

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