果实表达PGIPs的基因克隆及功能研究进展

多聚半乳糖醛酸酶(PGs)是病原真菌早期侵染植物的一个重要致病因子。多聚半乳糖醛酸酶抑制蛋白(PGIPs)作为植物防御蛋白,能特异性抑制真菌分泌的多聚半乳糖醛酸酶,并通过延长寡聚半乳糖醛酸(OGs)的稳定期激活植物防御反应。综述PGIPs在植物细胞中的定位,PGIPs与PGs之间的作用方式,PGIPs基因的分离与克隆,以及PGIPs对果实感病的影响,并对PGIPs的研究前景进行展望。     

多聚半乳糖醛酸酶抑制蛋白的结构、功能以及应用研究进展

真菌病害严重影响植物的生长发育。为了自我保护,植物进化出了许多抵御病原真菌入侵的策略,例如防御相关蛋白的产生。多聚半乳糖醛酸酶抑制蛋白（polygalacturonase-inhibiting proteins,PGIPs）是近年来研究较多的一种植物防御蛋白,它能与真菌分泌的多聚半乳糖醛酸酶（polygalacturonases,PGs）特异性结合,降低PGs水解植物细胞壁的活性并在植物体内累积能激活多种防御反应的长链寡聚半乳糖醛酸（oligogalacturonides,OGs）,从而达到抑制真菌侵染的目的。主要介绍了PGIPs的结构、功能及其抗菌机理,并综述了PGIPs在国内外转基因抗病育种中的应用研究进展。     

PGIP在植物抗病方面的研究进展

至今为止,已在20多种植物体内发现了多聚半乳糖醛酸酶抑制蛋白(PGIP)。这类蛋白质主要集中于细胞壁和内膜系统,但在不同生长时间、不同品种及不同器官中其含量是不一样的,研究表明这种差异与植物的抗性强弱有着密切关系。PGIP是病原真菌分泌的endo_PG的抑制剂,因此能延缓病原真菌对植物细胞壁的降解。来自菜豆和小麦的实验证据表明病原真菌侵染植株能诱导pgip基因高水平转录、表达,但pgip基因家族对这种诱导信号应答的分子机制待于进一步研究。     

PGIP在植物抗病方面的研究进展

至今为止,已在２０多种植物体内发现了多聚半乳糖醛酸酶抑制蛋白（ＰＧＩＰ）。这类蛋白质主要集中于细胞壁和内膜系统,但在不同生长时间、不同品种及不同器官中其含量是不一样的,研究表明这种差异与植物的抗性强弱有着密切关系。ＰＧＩＰ是病原真菌分泌的ｅｎｄｏ－ＰＧ的抑制剂,因此能延缓病原真菌对植物细胞壁的降解。来自菜豆和小平的实验证明表明病原真菌侵染植株能诱导ｐｇｉｐ基因高水平转录、表达,但ｐｇｉｐ基因家族对     

通过苜蓿愈伤组织生产植物病害防御蛋白

真菌病原体借助于能降解细胞壁多糖的多聚半乳糖醛酸酶(PG)而侵袭植物。为了抵御病原体的侵害,一些植物组织含有能抑制细胞壁降解生物的PG活性的蛋白(PGIP)。有关PGIP的研究很少,因为,可从植物组织中纯化出来的这种物质有限。     

果实多聚半乳糖醛酸酶分子生物学研究进展

多聚半乳糖醛酸酶（PG酶）是一种在植物细胞壁降解中起重要的作用的酶。作者介绍了PG酶在果实成熟软化中的作用。概述了PG酶基因及其表达调控,评述了乙烯对PG酶合成的影响。     

向日葵花盘水提物对硫色镰刀菌及其细胞壁降解酶活性抑制特性

通过抑菌及细胞壁降解酶活性试验,研究向日葵花盘(sunflower disc,SFD)水提物对引起马铃薯干腐病主要病原菌——硫色镰刀菌(Fusarium sulphureum)生长及其侵染不同马铃薯品种时分泌的多聚半乳糖醛酸酶(polygalacturonase,PG)、果胶甲基半乳糖醛酸酶(polymethyl-ga...     

Endo-PG诱导培养小麦细胞PGIP产生的研究

内切多聚半乳糖醛酸酶（endo-polygalacturonase,endo-PG）是待异水解细胞壁成分多聚半乳糖醛酸的酶,水解产生的10～13个糖基的寡聚半乳糖醛酸片段是活性诱导因子,激活植物自身防御系统．我们已研究发现单子叶植物小麦中存在多聚半乳糖醛酸酶抑制蛋白（polygalacturonaseinhibitingprotein,PGIP）,并已将其分离纯化,对其性质作了初步研究[1,2]文献报导[3]PGIP是在未分化的细胞中合成的．本文报导在悬浮培养的小麦细胞中加入Endo-PG观察其PGIP的生成,比较赤霉病的高抗品种与低抗品种中PGIP的合成情况,探讨PGIP与植物防御作…     

参与植物天然免疫的LRR型蛋白

植物含有多种富含亮氨酸重复序列(LRRs)结构的蛋白质,它们在植物天然免疫中发挥着重要作用。参与植物防御反应的LRR型蛋白家族包括:类受体蛋白激酶、抗病基因编码蛋白质、多聚半乳糖醛酸酶抑制蛋白和伸展蛋白家族。最近,人们发现植物免疫系统包含:病原相关分子模式(PAMP)激发的免疫性(PTI),即类受体蛋白激酶识别病原菌PAMPs,启动植物防卫反应;病原菌效应子激发的免疫性(ETI),即抗病基因编码蛋白质识别效应子,启动植物防卫反应。除此之外,细胞壁是植物细胞的天然保护屏障。多聚半乳糖醛酸酶抑制蛋白和伸展蛋白通过维护细胞壁,抵御病原菌入侵。我们综述了植物中LRRs蛋白的结构特征与不同种类的LRR蛋白介导免疫反应的分子机制,讨论了LRR型蛋白在植物免疫过程中的意义及存在的问题,指出搜寻配体和下游信号分子将是LRR型蛋白研究热点。     

小麦内切多聚半乳糖醛酸酶抑制蛋白的分离纯化研究

小麦内切多聚半乳糖醛酸酶抑制蛋白的分离纯化研究郑远旗,杨宗剑,李建吾,周立,吴文莲（四川大学生物系,成都６１００６４）余露（中国科学院成都生物研究所,成都６１００４１）关键词内切多聚半乳糖醛酸酶抑制蛋白;内切多聚半乳糖醛酸酶;纯化;小麦内切多聚半乳糖...     

Fungal pathogenesis: gene clusters unveiled as secrets within the Ustilago maydis code

The genome sequence of a second plant pathogenic fungus is now available, revealing unique gene clusters encoding secretory proteins that are induced during infection and regulate pathogenesis. Gene clusters play important roles in pathogenic fungi, yet their evolution and maintenance remain a mystery.     

Sexual reproduction and dimorphism in the pathogenic basidiomycetes

Many fungi in the Basidiomycota have a dimorphic life cycle, where a monokaryotic yeast form alternates with a dikaryotic hyphal form. Most of the dimorphic basidiomycetes are pathogenic on plants, animals or other fungi. In these species, infection of a host appears to be closely linked to both dimorphism and the process of sexual reproduction. Sex in fungi is governed by a specialized region of the genome known as the mating type locus that confers cell-type identity and regulates progression through the sexual cycle. Here we investigate sexual reproduction and lifestyle in emerging human pathogenic yeasts and plant pathogenic smuts of the Basidiomycota and examine the relationship among sex, dimorphism and pathogenesis.     

Mutualistic interactions on a knife-edge between saprotrophy and pathogenesis

Saprophytic, ectomycorrhizal (ECM) and pathogenic fungi play a key role in carbon and nutrient cycling in forest ecosystems. Whereas more than 50 genomes of saprotrophic and pathogenic fungi have been published, only two genomes of ECM fungi, Laccaria bicolor and Tuber melanosporum, have been released. Comparative analysis of the genomes of biotrophic species highlighted convergent evolution. Mutualistic and pathogenic biotrophic fungi share expansion of genome size through transposon proliferation and common strategies to avoid plant detection. Differences mainly rely on nutritional strategies. Such analyses also pinpointed how blurred the molecular boundaries are between saprotrophism, symbiosis and pathogenesis. Sequencing of additional ECM species, as well as soil saprotrophic fungi, will facilitate the identification of conserved traits for ECM symbiosis and those leading to the transition from white-rotting and brown-rotting to the ECM lifestyle.     

组学技术在核盘菌研究中的应用

核盘菌Sclerotinia sclerotiorum是一种典型的死体营养型植物病原真菌,全球分布且寄主范围广泛,严重危害多种植物,对农业生产造成严重损失。核盘菌研究主要集中在真菌生物学及病理学等方面。近年来,随着高通量分析技术的不断改进,多种组学技术为系统生物学研究提供了平台。文中主要综述利用多种组学研究方法在植物病原真菌核盘菌研究中的应用及研究进展,探讨开展植物病原物及病害发展的系统性研究思路,以期为核盘菌的分子生物学及致病机理等研究提供参考,同时也为其他植物病原物及病害系统研究提供理论依据。     

病原菌与自然植物种群Ⅲ.病原菌与寄主植物的共进化及媒体传布的菌病的种群模型

在自然植物种群中,病原菌与寄主植物不仅在个体发育的水平上相互作用,而且在系统发育的水平上相互作用。这后一种相互作用的结果就是病原菌与寄主植物的共进化。本文论述了病原菌与寄主植物共进化的主要方面病原菌的致病力和寄主植物种群的遗传结构。鉴于传媒方式在进化上具有重要意义,本文还简单介绍了媒体传布的菌病的种群模型     

Regulation of low-molecular weight organic acid production in fungi

Organic acids produced by fungi have been proposed to have many roles in wood-decay processes, lignocellulose degradation or plant pathogenesis involving saprotrophic or pathogenic fungi, as well as in nutrient acquisition and metal detoxification involving mycorrhizal or rhizosphere-inhabiting fungi. In comparison with other fungi, a considerable body of work has been devoted to the comprehension of biosynthesis pathways in fungi involved in industrial production of organic acids, and also in those involved in wood-decay processes and pathogenicity. In this review we therefore focus on information available from these different types of low-molecular weight organic acid (LMWOA) producing fungi in order to better understand the environmental cues involved in regulating production of LMWOAs.     

荧光蛋白报告基因在植物寄生真菌研究中的应用

综述菌根真菌、植物内生菌和植物病原真菌等植物寄生真菌转荧光蛋白基因研究现状.介绍转化载体的构建、转化方法及特基因的检测方法,以及转荧光蛋白基因技术在植物寄生真菌侵染过程研究中的应用,指出真菌转荧光蛋白基因存在的问题和展望.     

Comparative genome analysis of filamentous fungi reveals gene family expansions associated with fungal pathogenesis

Fungi and oomycetes are the causal agents of many of the most serious diseases of plants. Here we report a detailed comparative analysis of the genome sequences of thirty-six species of fungi and oomycetes, including seven plant pathogenic species, that aims to explore the common genetic features associated with plant disease-causing species. The predicted translational products of each genome have been clustered into groups of potential orthologues using Markov Chain Clustering and the data integrated into the e-Fungi object-oriented data warehouse (http://www.e-fungi.org.uk/). Analysis of the species distribution of members of these clusters has identified proteins that are specific to filamentous fungal species and a group of proteins found only in plant pathogens. By comparing the gene inventories of filamentous, ascomycetous phytopathogenic and free-living species of fungi, we have identified a set of gene families that appear to have expanded during the evolution of phytopathogens and may therefore serve important roles in plant disease. We have also characterised the predicted set of secreted proteins encoded by each genome and identified a set of protein families which are significantly over-represented in the secretomes of plant pathogenic fungi, including putative effector proteins that might perturb host cell biology during plant infection. The results demonstrate the potential of comparative genome analysis for exploring the evolution of eukaryotic microbial pathogenesis.     

木本曼陀罗内生真菌抗菌活性的筛选研究

从木本曼陀罗植物内生真菌中筛选高效抗菌活性的菌株。选择与人类和植物相关的36株病原微生物,分别对分离自木本曼陀罗(Datura arborea L.)植物的内生真菌77株进行了发酵代谢产物的抗菌活性筛选研究。结果显示:对细菌病原菌、皮肤致病真菌、植物致病真菌有抑制作用的内生真菌分别有24,9,17株,其中5株内生真菌对10种以上的供试病原菌有明显的抑制作用,活性最好的1株对20种病原菌有较强抑制活性,最大抑菌圈直径达48mm。这说明木本曼陀罗植物内生真菌抗菌能力较强,抗菌谱较广。     

A Network Approach to Predict Pathogenic Genes for Fusarium graminearum

Fusarium graminearum is the pathogenic agent of Fusarium head blight (FHB), which is a destructive disease on wheat and barley, thereby causing huge economic loss and health problems to human by contaminating foods. Identifying pathogenic genes can shed light on pathogenesis underlying the interaction between F. graminearum and its plant host. However, it is difficult to detect pathogenic genes for this destructive pathogen by time-consuming and expensive molecular biological experiments in lab. On the other hand, computational methods provide an alternative way to solve this problem. Since pathogenesis is a complicated procedure that involves complex regulations and interactions, the molecular interaction network of F. graminearum can give clues to potential pathogenic genes. Furthermore, the gene expression data of F. graminearum before and after its invasion into plant host can also provide useful information. In this paper, a novel systems biology approach is presented to predict pathogenic genes of F. graminearum based on molecular interaction network and gene expression data. With a small number of known pathogenic genes as seed genes, a subnetwork that consists of potential pathogenic genes is identified from the protein-protein interaction network (PPIN) of F. graminearum, where the genes in the subnetwork are further required to be differentially expressed before and after the invasion of the pathogenic fungus. Therefore, the candidate genes in the subnetwork are expected to be involved in the same biological processes as seed genes, which imply that they are potential pathogenic genes. The prediction results show that most of the pathogenic genes of F. graminearum are enriched in two important signal transduction pathways, including G protein coupled receptor pathway and MAPK signaling pathway, which are known related to pathogenesis in other fungi. In addition, several pathogenic genes predicted by our method are verified in other pathogenic fungi, which demonstrate the effectiveness of the proposed method. The results presented in this paper not only can provide guidelines for future experimental verification, but also shed light on the pathogenesis of the destructive fungus F. graminearum.