本文選題：禾谷鐮刀菌 + metacaspase��； 參考：《山東農(nóng)業(yè)大學(xué)》2017年碩士論文

【摘要】：禾谷鐮刀菌(Fusarium graminearum)是導(dǎo)致小麥赤霉病(Fusarium head blight,FHB)的主要致病真菌,也可侵染大麥(Hordeum vulgare)和其他禾谷類(lèi)作物。小麥赤霉病不僅導(dǎo)致產(chǎn)量的損失,而且會(huì)產(chǎn)生一些真菌毒素,如脫氧雪腐鐮刀菌烯醇(Deoxynivallenol,DON)。DON毒素是該病原物主要的真菌毒素,DON對(duì)人畜健康和安全造成巨大危害,并且是病原菌侵染植物過(guò)程中的重要毒力因子。病害控制主要是選擇抗病品種和殺真菌劑,但效果不佳。凋亡作為重要的生理學(xué)過(guò)程之一,是細(xì)胞程序性死亡的常見(jiàn)形式。半胱天冬氨酸酶(metacaspase)是一種半胱氨酸依賴(lài)的蛋白酶,是原核生物和真菌中參與凋亡過(guò)程的重要因子。目前,Metacaspase在植物病原真菌中尚沒(méi)有相關(guān)研究和報(bào)道。通過(guò)NCBI(National Center for Biotechnology Information)搜索和BLAST比對(duì),在禾谷鐮刀菌數(shù)據(jù)庫(kù)中發(fā)現(xiàn)2個(gè)metacaspase基因,分別命名為FgMCA1和FgMCA2。系統(tǒng)發(fā)育樹(shù)和序列比對(duì)分析發(fā)現(xiàn):2個(gè)FgMCA同時(shí)包含metacaspase特征性結(jié)構(gòu)域:P20和P10,2個(gè)FgMCA蛋白都屬于第一類(lèi)metacaspase。通過(guò)Split-marker PCR方法獲得FgMCA基因敲除突變體(?mca1和?mca2)。基因敲除后發(fā)現(xiàn):相對(duì)于野生型,2個(gè)敲除突變體?mca1和?mca2生長(zhǎng)速度和分生孢子產(chǎn)量均有所下降。小麥穗和玉米須接種實(shí)驗(yàn)發(fā)現(xiàn),2個(gè)突變體的致病性顯著下降;與野生型相比,DON毒素產(chǎn)量和TRI基因表達(dá)水平也顯著降低。在含有過(guò)氧化氫的CM培養(yǎng)基上,FgMCA的2個(gè)敲除突變體提高了對(duì)H2O2的抗性。在H2O2誘導(dǎo)的條件下,2個(gè)突變體的凋亡率均下降。對(duì)FgMCAs蛋白的亞細(xì)胞定位研究發(fā)現(xiàn),2個(gè)蛋白都定位于細(xì)胞質(zhì)中。綜上所述,F.graminearum基因組中含有2個(gè)FgMCA基因,遺傳分析發(fā)現(xiàn)它們參與調(diào)控菌絲生長(zhǎng)、分生孢子形成、致病性和DON產(chǎn)量,敲除突變體提高了對(duì)H2O2的抗性水平,降低了H2O2脅迫下的細(xì)胞凋亡率。
[Abstract]:Fusarium graminearum (Fusarium graminearum) is the leading cause of wheat scab (Fusarium head, blight, FHB) the main pathogenic fungi, can also infect barley (Hordeum vulgare) and other cereal crops. Wheat scab not only lead to loss of output, but also can produce some fungal toxins, such as deoxynivalenol (Deoxynivallenol DON).DON toxin is one of the main pathogens of DON mycotoxin, causing great harm to human and animal health and safety, and is an important virulence factor of pathogen infection in plants. Disease control is mainly the selection of resistant varieties and fungicides, but the effect is poor. Apoptosis as an important physiological process is one of the common forms of. Programmed cell death. Caspase dependent (metacaspase) is a cysteine protease, is an important factor in the apoptosis process in prokaryotes and fungi. At present, Me Tacaspase in plant pathogenic fungi. There is no relevant reports by NCBI (National Center for Biotechnology Information BLAST) search and comparison, 2 metacaspase genes found in Fusarium graminearum database, named FgMCA1 and FgMCA2. phylogenetic tree system and sequence alignment analysis showed that: 2 FgMCA also contains the metacaspase characteristic domains P20 and P10,2 FgMCA proteins belong to the first class of metacaspase. through the Split-marker PCR method to obtain the FgMCA gene knockout mutant (? Mca1? Mca2). Gene knockout found: compared to wild-type, 2 knockout mutants? Mca1 and? Growth rate and spore yield decreased mca2 and wheat. Corn inoculation experiment showed that the pathogenicity of 2 mutants decreased significantly; compared with the wild type, the expression of DON and yield of TRI toxin gene were also reduced significantly. In the presence of peroxide Hydrogen on CM medium, FgMCA 2 knockout mutants enhanced resistance to H2O2. After H2O2 induction, the apoptosis of 2 mutants decreased. To study the subcellular localization of FgMCAs protein found that 2 proteins were localized in the cytoplasm. In summary, F.graminearum genome contains 2 FgMCA gene, genetic analysis showed that they are involved in the regulation of mycelial growth, conidia formation and pathogenicity and DON yield, knockout mutant improves the level of resistance to H2O2, decreasing the apoptosis rate under H2O2 stress.

【學(xué)位授予單位】：山東農(nóng)業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：S435.121.45

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 張洪濱;柳金偉;劉秉江;劉冰;梁元存;;山東省小麥赤霉病菌種群組成及其致病力分化[J];植物保護(hù)學(xué)報(bào);2013年01期

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本文編號(hào)：1739535