稻瘟病菌MoPEX33、MoPEX23和MoPEX24基因功能分析

发布时间：2018-03-11 09:29

本文选题：稻瘟病菌　切入点：过氧化物酶体　出处：《浙江师范大学》2016年硕士论文　论文类型：学位论文

【摘要】：稻瘟病菌Magnaporthe oryzae)是子囊菌亚门丝状真菌,可引起水稻重要病害——稻瘟病。同时,稻瘟病菌还是植物病原真菌研究模式生物,其致病机理研究是植物病理学的重要组成部分。过氧化物酶体是稻瘟病菌细胞中的重要细胞器,参与细胞中脂肪酸β-氧化、磷脂合成以及活性氧代谢等重要机制。过氧化物酶体的的合成,分化,遗传至少需要32个蛋白,我们称这些蛋白为peroxins,编码这些蛋白的基因称为PEX基因。过氧化物酶体对接复合体是由Pex13p、 Pex14p和Pex17p三个蛋白组成的。稻瘟病菌中有Pex13p、Pex14p,但是却没有Pex17p的同源蛋白,而是存在1个类似于Pex14p与Pex17p蛋白的Mopex33p,它具有与Pex14p高度同源的保守N末端,同时C端存在一段类似于酵母Pex17p的螺旋区域。研究显示,过氧化物酶体不仅在不同物种和不同组织中有显著差异,而且可以根据环境刺激改变过氧化物酶体数量和蛋白。目前发现,与过氧化物酶体增殖相关基因有PEX1l家族,PEX23家族。在稻瘟病菌中,含有PEX23家族的同源蛋白,分别为Mopex23p和Mopex24p。为了了解稻瘟病菌中MoPEX33、MoPEX23和MoPEX24三个基因的生物学功能及其作用机制,本文对MoPEX33、MoPEX23和MoPEX24展开了研究,结果发现突变体△mopex33-4中过氧化物酶体基质蛋白部分PTS1基质蛋白不能正确定位；致病性分析结果显示△mopex33-4的致病性显著减弱,但仍有一定的致病性,致病侵染结果也显示其侵染进程减慢：△mopex33-4的生长速率轻微减弱,气生菌丝减少,产孢量下降,孢子萌发、附着胞形成延迟,附着胞内甘油膨压降低,对脂肪酸代谢能力下降,细胞壁完整性降低,活性氧耐受能力降低,因此我们认为MoPEX33基因是过氧化物酶体基质蛋白的正常运输所必需且对稻瘟菌的致病性具有一定的影响；而MoPEX23和MoPEX24的缺失对稻瘟病菌无显著影响,推测丝状真菌稻瘟病菌过氧化物酶体增殖模式与酵母不同。
[Abstract]:Rice blast fungus Magnaporthe oryzae is a filamentous fungus of ascomycetes, which can cause rice blast. Peroxisome is an important organelle in rice blast fungus cells, which is involved in 尾 -oxidation of fatty acids. Phospholipid synthesis and reactive oxygen metabolism are important mechanisms. The synthesis, differentiation and heredity of peroxisome require at least 32 proteins. We call these proteins peroxins.The genes that encode these proteins are called PEX genes. The peroxisome docking complex is made up of three proteins, Pex13, Pex14, and Pex17p. Instead, there is a Mopex33psimilar to Pex14p and Pex17p protein, which has a conserved N terminal with high homology with Pex14p, and a helical region similar to yeast Pex17p. Peroxisome not only varies significantly in different species and tissues, but also changes the number and protein of peroxisome in response to environmental stimuli. The genes related to peroxisome proliferation include the PEX1l family, the pex 23 family, and the homologous proteins of the PEX23 family, Mopex23p and Mopex24p. in order to understand the biological function and the mechanism of the three genes, MoPEX33, MoPEX23 and MoPEX24, in rice blast fungus. In this paper, we studied MoPEX33, MoPEX23 and MoPEX24, and found that some PTS1 matrix proteins of peroxisome matrix protein in mutant mopex33-4 could not be located correctly, and pathogenicity analysis showed that the pathogenicity of mopex33-4 was significantly weakened, but it still had some pathogenicity. The result of pathogenic infection also showed that the infection process was slowed down: the growth rate of mopex33-4 decreased slightly, the hyphal production decreased, the spore germination, the formation of attachment cell delayed, the pressure of glycerol in attachment cell decreased, and the metabolic ability of fatty acid decreased. The integrity of cell wall was decreased, and the ability of reactive oxygen species tolerance was decreased. Therefore, we believe that MoPEX33 gene is necessary for the normal transport of peroxisome matrix proteins and has a certain effect on the pathogenicity of rice blast fungus. However, the absence of MoPEX23 and MoPEX24 had no significant effect on rice blast fungus, suggesting that the peroxisome proliferation pattern of filamentous fungi was different from that of yeast.
【学位授予单位】：浙江师范大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S435.111.41

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