多孢节丛孢DNA随机扩增多态性及变种分析

本文对少孢节丛孢的１０个菌株进行了胡机扩增多态性ＤＮＡ（ＲＡＰＤ）分析。４个随机引物获得的ＲＡＰＤ谱带并呈多态性,单个引物获得的ＲＡＰＤ片段数在２～１３个之间。供试的１０个菌株来自不同的地方,形态差异较大,但四个随机引物的扩增结果基本上都体现了少孢节丛孢种的特征“指纹”,基于遗传距离分析和应用ＵＰＧＭＡ方法构建的分子系统树显示,少孢节丛孢不同地理群体间不存在遗传分化,提示在少孢节丛孢群体中没有显著     

弯孢节丛孢和厚皮单顶孢菌株的RAPD分析

对来自不同地方的７个弯孢节丛孢（Ａｒｔｈｒｏｂｏｔｒｙｓ ｍｕｓｉｆｏｒｍｉｓ Ｄｒｅｃｈｓｌｅｒ）的９个厚皮单顶孢（Ｍｏｎａｃｒｏｓｐｏｒｉｕｍ ｅｕｄｅｒｍａｔｕｍ（Ｄｒｅｃｈｓｌｅｒ）Ｓｕｂｒａｍ）标准菌株用４个随机引物（ＯＶＷ－１８,ＯＰＷ－１６,ＯＰＭ－１,ＯＰＫ－１９）进行了随机扩增多态性ＤＮＡ（ＲＡＰＤ）分析。扩增谱带聚类分析结果不能将弯孢节丛孢和厚皮单顶孢的菌株分开,具有附属丝的菌     

弯孢节丛孢和厚皮单顶孢菌株的RAPD分析

对来自不同地方的7个弯孢节丛孢（ArthrobotrysmusiformisDrechsler）和9个厚皮单顶孢（Monacrosporiumeudermatum（Drechsler）Subram）标准菌株用4个随机引物（OPW-18、OPW－16、OPM-1、OPK-19）进行了随机扩增多态性DNA（RAPD）分析。扩增谱带聚类分析结果不能将弯孢节丛孢和厚皮单顶孢的菌株分开,具有附属丝的菌株没有被聚在一起,菌株间地理起源上的亲缘关系也没有体现,证明RAPD分析不能作为节丛孢属和单顶孢属的属间鉴别分析,附属丝地捕食线虫真菌不具分类学意义,不能以之作为成立小掘氏霉属的证据,系统聚类关系与地理来源基质也没有相关性。     

节丛孢属rDNA ITS区RFLPs分析

利用ＰＣＲ－ＲＦＬＰ方法对捕食线虫真菌节丛孢属进行了系统发育研究。以ＩＴＳ１和ＩＴＳ４为引物对该属１０种１２个菌株的核糖体ＤＮＡ转录间区（ＩＴＳ）进行了ＰＣＲ扩增,４种内切酶（ＡｌｕⅠ、ＨａｅⅢ、ＨｐａⅡ、ＴａｑⅠ）酶切。结果表明该属的ＩＴＳ区长度没有明显差异,其长度范围在６５８－７０５之间,酶切图谱能体现不同种间的多态性,根据４种内切酶酶切结果,利用ＵＰＧＭＡ法构建的节丛孢属分子系统树,基于体现     

滇西北地区冬虫夏草和阔孢虫草的遗传分化研究

应用随机扩增多态性ＤＮＡ（ＲＡＰＤ）技术对来自云南西北部高黎贡山和丽江玉龙雪山的６个冬虫夏草Ｃｏｒｄｙｃｅｐｓ ｓｉｎｅｎｓｉｓ（Ｂｅｒｋ．）Ｓａｃｃ．,来自德钦地区三个地方的８个阔孢虫草Ｃ．ｃｒａｓｓｉｓｐｏｒａ Ｚａｎｇ,Ｙａｎｇ ｅｔ Ｌｉ以及来自云南昆明的一个蛹虫草Ｃ．ｍｉｌｉｔａｒｉｓ （Ｖｕｉｌｌ）Ｆｒ．进行分析。１８个随机引物获得的ＲＡＰＤ谱带清晰并呈现多态。遗传距离分析表明,冬虫夏     

澳大利亚棉花黄萎病菌DNA多态性及其地理分布相关性研究

应用ＲＡＰＤ技术对澳大利亚东南部八个主要棉花种植区的９９个棉花黄萎病菌菌株进行了ＤＮＡ多态性分析。结果表明用１０个筛选的随机引物对供试菌株的全基因组ＤＮＡ扩增,共获得９２条ＲＡＰＤ谱带,其中５５．４％的谱带为多态带。经类聚分析,供试菌株类聚为１５个ＲＡＰＤ遗传指纹相似组,其中１０个指纹相似组的菌株与其采集区域有明显相关性,其余５个指纹相似组的菌株为普通分布的指纹类型。     

澳大利亚棉花黄萎病菌DNA多态性及其地理分布相关性研究(英文)

应用ＲＡＰＤ技术对澳大利亚东南部八个主要棉花种植区的９９个棉花黄萎病菌菌株进行了ＤＮＡ多态性分析。结果表明用１０个筛选的随机引物对供试菌株的全基因组ＤＮＡ扩增,共获得９２条ＲＡＰＤ谱带,其中５５．４％的谱带为多态带。经类聚分析,供试菌株类聚为１５个ＲＡＰＤ遗传指纹相似组,其中１０个指纹相似组的菌株与其采集区域有明显相关性,其余５个指纹相似组的菌株为普通分布的指纹类型。     

冬虫夏草的随机扩增多态DNA及其遗传分化

本文对来自青藏高原３个区域５个具有代表性地方的１３个冬虫夏草样本进行随机扩增多态ＤＮＡ（ＲＡＰＤ）分析。１９个随机引物获得的ＲＡＰＤ谱带清晰并呈现多态,单个引物获得的ＲＡＰＤ片段数在３￣１０个之间。该１９个引物在每个样本中扩增的ＲＡＰＤ片段总数平均约为６５个。基于遗传距离分析,受试的１３个冬虫夏草样本中,来自同一地方的样本间遗传差异甚微,同一区域不同地方的样本间遗传差异较大,不同区域的样本间遗传差     

大豆灰斑病菌生理小种的RAPD标记

运用随机扩增多态性ＤＮＡ（ＲａｎｄｏｍａｍｐｌｉｆｉｅｄｐｏｌｙｍｏｒｐｈｉｃＤＮＡ,ＲＡＰＤ）技术对发生于中国东北的大豆灰斑病菌（Ｃｅｒｃｏｓｐｏｒｉｄｉｕｍｓｏｊｉｍｕｍ）的１０个生理小种进行基因组ＤＮＡ多态性分析,用１３个１０－核苷酸随机引物获得了１１１个ＲＡＰＤ标记,其中８６．５％具有多态性,通过聚类分析确定了供试小种间的亲缘关系,试验证明,ＲＡＰＤ技术分析大豆灰斑病菌遗传传变异可提供大量     

中国棉花枯萎菌生理小种的RAPD分析

利用随机扩增多态性ＤＮＡ（ＲＡＰＤ）分子标记方法对我国棉花枯萎菌３个生理小种（３、７、８号）进行遗传多样性分析,以筛选出的１０个随机引物对采自我国１１个省（自治区）的２６个代表菌株及国外３个不同生理小种对照菌株进行ＲＡＰＤ－ＰＣＲ扩增,共产生了１４０个ＲＡＰＤ分子标记,其中８７．８％具有多态性。通过聚类分析确定了供试小种间的亲缘关系,并寻找到了我国３、７、８号小种的特异条带,为确立我国棉花枯萎菌生     

捕食线虫丝孢菌的菌寄生性测定

研究了节丛孢Arthrobotrys、单顶孢Monacrosporium和隔指孢Dactylella三个捕食线虫丝孢菌属16个菌株,对水稻立枯丝核菌RhizoctoniasolaniAG1、大豆核盘菌Sclerotiniasclerotiorum、茄科镰刀菌Fusariumsolani和恶疫霉Phytophthoracactorum四种常见土壤植物病原真菌的菌寄生性。结果表明供试菌可以通过弹簧式菌丝圈缠绕、类附着胞结构吸附、简单的菌丝缠绕或者贴附寄主菌丝生长四种方式寄生病原菌。其中,绝大多数菌株对立枯丝核病菌有寄生作用,一些供试真菌对其它三种病原真菌有寄生现象。利用孢子液浸泡法测定了其中5种捕食线虫真菌对核盘菌菌核的寄生能力,显示有较高寄生率。     

寡孢节丛孢菌对羊捻转血矛线虫幼虫捕食作用*

报道５株寡孢菌在体外对羊捻转血矛线虫第３期幼虫的捕食效果。结果表明：５株寡孢节丛孢菌对捻转血矛线虫幼虫的捕获率分别为８８．６５％、７９．００％、７４．７２％、８７．０９％、８０．９１％,具有较高的捕杀线虫效果。寡孢节丛孢菌对捻转血矛线虫的作用方式主要是通过在线虫周围形成捕食菌网。     

Thioredoxin1 regulates conidia formation,hyphal growth,and trap formation in the nematode-trapping fungus Arthrobotrys oligospora

Arthrobotrys oligospora, a model nematophagous fungus that produces specific adhesive networks to capture nematodes, has been proposed as a potentially effective biological agent to control harmful plant-parasitic nematodes. Although thioredoxin has been characterized as playing important roles in many cellular processes in other species, its function in nematophagous fungi has not been studied. Here, the function of a thioredoxin homolog, Aotrx1, was investigated in A. oligospora. The encoding gene of Aotrx1 in the nematophagous fungus A. oligospora was knocked out by homologous recombination; strain growth was assessed. The ΔAotrx1 strain of A. oligospora showed a significant decrease in growth rate on different media (PDA, CMY, and TG), a 70% decrease of conidia production, and a lower germination rate compared with the wild type. The mutant strain was unable to form traps to capture nematodes and was more sensitive to SDS and H2O2. Thioredoxin is involved in conidia development, trap formation, normal mycelial growth, and resistance to environmental stresses in the nematode-trapping fungus A. oligospora.     

The predatory capability of three nematophagous fungi in the control of Haemonchus contortus infective larvae in ovine faeces

The effect of oral administration of three different nematode-trapping fungi, in aqueous suspension containing either Dactylaria sp. or Arthrobotrys oligospora conidia or Duddingtonia flagrans chlamydospores, on the number of Haemonchus contortus infective larvae in sheep faeces, was evaluated. The three selected species of fungi produce three-dimensional adhesive nets in the presence of nematodes. Sixteen Creole sheep were divided into four groups of four animals each. Groups 1 and 2 were orally drenched with a suspension containing 2x10(7) conidia of either A. oligospora or Dactylaria sp. Group 3, received a similar treatment, with D. flagrans chlamydospores, instead of conidia, being administered, at the same dose. Group 4 acted as control, without any fungi. Faecal samples were collected directly from the rectum of each sheep and faecal cultures were prepared and incubated at 15 and 21 days. Larvae were recovered from faecal cultures and counted. The highest reduction of the nematode population occurred in the D. flagrans group, reaching reductions of 96.3% and 91.4% in individual samplings in plates incubated for 15 and 21 days, respectively. Arthrobotrys oligospora showed moderate reductions in the faecal larval population, ranging between 25-64% at 15 days incubation. In general, Dactylaria sp., was less efficient in its trapping ability. Despite the inconsistent results with Dactylaria sp., reduction percentages of 73.4% and 80.7% were recorded in individual samplings during the first and second days, in plates incubated for 15 days. Duddingtonia flagrans, was shown to be a potential biological control agent of H. contortus infective larvae.     

绿木霉Gv29-8丝氨酸蛋白酶S8/S53超家族基因特性及功能

【背景】丝氨酸蛋白酶在木霉菌生物防治过程中发挥重要作用。【目的】研究绿木霉丝氨酸蛋白酶S8/S53超家族基因信息及其生物学功能,进而为该蛋白酶生防制剂的开发及基因改造提供理论支持。【方法】通过生物信息学分析方法,从绿木霉Gv29-8基因组中鉴定出23个丝氨酸蛋白酶基因,以少孢节丛孢菌ATCC 24927基因组中鉴定的4个丝氨酸蛋白酶基因作为对照,对这27个丝氨酸蛋白酶基因的特性、蛋白结构、进化地位、功能等进行预测分析。【结果】27个基因结构差异较大,编码的蛋白具有典型的丝氨酸蛋白酶催化三联体结构,属于S8/S53超家族,分为6个亚家族,同一亚家族的蛋白酶保守区长度相近,相似性较高,催化残基附近序列比较保守。系统进化分析显示,同一亚家族丝氨酸蛋白酶聚为一类。【结论】绿木霉和少孢节丛孢菌的部分丝氨酸蛋白酶基因在结构和蛋白性质上相似性强,亲缘关系较近,均属于S8_PCSK9_ProteinaseK_like亚家族,推测绿木霉与少孢节丛孢菌该亚家族的丝氨酸蛋白酶具有相似的功能,可抑制植物病原真菌和降解线虫体壁。     

A Putative Adhesin-encoding Gene AOL_s00007g5 is involved in the Mycelial Growth and Development of Nematode-trapping Fungus Arthrobotrys oligospora

Applied Biochemistry and Microbiology - Arthrobotrys oligospora is one of the most commonly studied fungi that can form abundant traps to capture and consume nematodes at the parasitic stage....     

Two Rab GTPases play different roles in conidiation,trap formation,stress resistance,and virulence in the nematode-trapping fungus Arthrobotrys oligospora

Applied Microbiology and Biotechnology - Rab GTPases are the largest group of the small GTPases family, which play a pivotal role in the secretion of proteins. Arthrobotrys oligospora is a...     

Induction of Nematode-Trapping Organs in the Predacious Fungus Arthrobotrys oligospora (Hyphomycetales) by Infective Larvae of Ostertagia ostertagi (Trichostrongylidae)

Laboratory experiments were designed to study the influence of temperature, concentrations of nematodes, oxygen tension, light, and nutrient levels, on the induction of nematode-trapping hyphal nets in the predacious fungus Arthrobotrys oligospora. When induced by infective Ostertagia ostertagi larvae, a maximum number of nets was produced at 20°C, at which temperature nets in surplus were produced at larval concentrations up to 1,000 larvae per cm2. A. oligospora did not produce nets in an anaerobic atmosphere containing 21 % CO2 (v/v), and net induction was suppressed to a certain degree by exposure to light. The composition of the medium had an important influence on the saprophytic growth and the net-forming capability of A. oligospora as a maximum number of nets was induced at a relatively low concentration of corn meal supporting the relatively sparse mycelium. It was shown that a proportion of trapping nets in A. oligospora maintained their trapping potential for more than 7 weeks when the temperature was below 25°C. Induction of nematodetrapping organs in A. oligospora is discussed in relation to control of infective nematode parasite larvae in cow pats.     

A fungal lectin and its apparent receptors on a nematode surface

Abstract A lectin was isolated from the nematode-trapping fungus Arthrobotrys oligospora . This carbohydrate-binding protein was developmentally regulated and was found only on trap-bearing mycelia. The lectin receptor on the surface of the nematode Panagrellus redivivus has, furthermore, been investigated using homogenates from whole nematodes or nematode cuticle. The ability of macromolecules from nematodes, fractionated according to M _r and lectin affinities, to inhibit the capture of nematodes by A. oligospora was tested using an inhibition assay, based on a simple dialysis membrane technique. One major lectin-binding glycoprotein, with apparent M _r of 65 000, was isolated from the nematode cuticle.     

Morphogenesis and significance of hyphal coiling by nematode-trapping fungi in mycoparasitic relationships

Abstract The mycoparasitic behaviour of some nematode-trapping fungi was investigated. These organisms interacted with other soil fungi by hyphal coiling around the host hyphae. A detailed study with Arthrobotrys oligospora revealed that different fungi, representing all taxonomic groups, were attacked.
In dual cultures, the interaction between A. oligospora and Rhizoctonia solani occurred soon after hyphal contact, irrespective of the nutrient level of the medium. Coiling was also observed when the two organisms were grown in sterilized soil. The coils possessed a high metabolic activity compared to the surrounding hyphae, as was indicated by fluorescence microscopy of fluorescein diacetate (FDA)-stained preparations. On the ultrastructural level, developing coils showed an abundance of membranous vesicles which developed from tubular-shaped endoplasmic reticulum. At the site of coiling, a strong cell wall proliferation was observed in the Rhizoctonia cells. The cytoplasm of these cells subsequently disintegrated. The death of the cells was confirmed in vital staining experiments. Penetration of intact Rhizoctonia cells was not observed. The interaction between A. oligospora and R. solani is interpreted in terms of competition for nutrients.