药用植物内生真菌研究进展

我国药用植物种类丰富,但受植物资源生长周期长、产量低等限制,难以满足人类的需要。而其内生真菌丰富多样,生长快,易培养,且可以产生与宿主相同或相似的天然活性物。利用内生真菌发酵生产抗菌、抗肿瘤等天然活性物质,不仅有望解决市面上部分药物供不应求的现状,还能有效地保护珍稀、濒危的药用植物资源。本文概述了药用植物内生真菌宿主植物的选择、内生真菌分离及其次级代谢产物分离纯化和活性研究,并对研究中存在的问题进行了讨论,以期为药用植物内生真菌研究提供方法和思路。     

Screening for Endophytic Fungi with Antitumour and Antifungal Activities from Chinese Medicinal Plants

Summary One hundred and thirty endophytic fungi isolated from 12 Chinese traditional medicinal plants collected at Yuanmou county and Dawei Mountain, Yunnan province, southwest China, were tested for antitumour and antifungal activities by MTT assay on human gastric tumour cell line BGC-823 and the growth inhibition test against 7 phytopathogenic fungi. The results showed that fermentation broths from 9.2% of the isolates exhibited antitumour activity and 30% exhibited antifungal activity, moreover, some of them exhibited broad-spectrum antifungal activity. The active isolates were identified to 32 taxa. The results indicate that the endophytic fungi of Chinese traditional medicinal plants are promising sources of novel bioactive compounds.     

Diversity and Antimicrobial and Plant-Growth-Promoting Activities of Endophytic Fungi in Dendrobium loddigesii Rolfe

Endophytic fungi are ubiquitously distributed in orchids and have a great impact on the host plant. The diversity of endophytic fungi in the medicinal orchid Dendrobium loddigesii Rolfe was investigated and their bioactivities in microbe and plant growth were explored here. Endophytic fungi were identified by using morphological and molecular biological methods. Antimicrobial activity was determined by a standard disk assay. Activity in promoting plant growth was confirmed by root inoculation of endophytic fungi in seedling tray and pot experiments. Overall, 48 isolates were isolated from D. loddigesii and identified to belong to 18 genera, with Fusarium and Acremonium being the most dominant populations. A total of 17 isolates belonging to 9 genera were screened for their antimicrobial activity, and Fusarium spp., 8 of the 17 isolates, was also the dominant population. In the seedling tray experiment, two isolates, one of Fusarium named DL26 and the other of Pyrenochaeta named DL351, were shown to enhance plant growth in alder bark–humus medium, and the latter displayed weak activity against Bacillus subtilis (As 1.308) and Aspergillus fumigatus (As 3.2910). In the pot experiment, after inoculation of DL26 and DL351, five out of seven media were fit for plant-endophyte symbionts. Medium #1 of red brick fragments and sphagna was optimal in accelerating plant growth. In conclusion, a great diversity of endophytic fungi in D. loddigesii was first confirmed in a considerable proportion of antimicrobial isolates. Furthermore, two endophytes exhibited the ability to enhance plant growth although their activities were influenced by the growth media.     

云南12种药用植物内生真菌分离及抗肿瘤活性菌株筛选

从马尾树、断肠草和白花蛇舌草等十二种云南药用植物中共分离到内生真菌263株,以卤虫模型对其中130株进行了抗肿瘤活性筛选,结果表明,有56.9%的菌株LD50≥4,39.2%的菌株LD50≥8,25.4%的菌株LD50≥16。以人胃癌细胞株BGC-823对LD50≥16的高活性菌株进行MTT法复筛,结果表明,有12株菌显示了细胞毒活性,抑制率从39.24%到100%不等。进一步研究表明,菌株D126和MT13对人白血病细胞株K562显示了较强的细胞毒活性,IC50分别为1∶438和1∶919。在12种植物中,小桐子的抗肿瘤活性菌株比率最高,为37.5%,其次为曼陀罗,为25.0%,而乌头、木瓜红、大花八角和重楼中未分离到抗肿瘤活性菌株。经鉴定,抗肿瘤活性菌株分属于12个分类单元     

三种水生植物内生真菌多样性及其抗真菌活性

从华凤仙(Impatiens chinensis L.)、问荆(Equisetum arvense L.)和轮叶狐尾藻(Myriophyllum verticillatum L.) 3种植物中共分离到内生真菌155株。经鉴定, 它们分属于26个不同的分类单元。以杨桃炭疽菌(Colletotrichum gloeosporioides)、香蕉疫霉(Phytophthora nicotianae)和腐皮镰刀菌(Fusarium solani)等6种植物病原真菌为指示菌, 对3种水生植物内生真菌代谢产物进行抗菌活性研究。结果表明, 有37株内生真菌(占分离菌株总数的23.9%)显示出对一种或多种病原菌的抑菌活性。来自华凤仙、问荆和轮叶狐尾藻的抗菌活性菌株比例分别为29.2%、13.9%及37.1%, 都远低于已报道的陆生植物内生真菌中活性菌株的比例。抗菌活性菌株主要分布于枝孢属(Cladosporium)、木霉属(Trichoderma)和地霉属(Geotrichum)等5个属中。     

Mycorrhizal Fungi Promote Growth and Nitrogen Utilization by Dendrobium nobile (Orchidaceae)

Mycorrhizal associations play a key role in the life cycle and evolutionary history of orchids. Although most orchid species are tropical and epiphytic, their mycorrhizae are poorly understood compared with those of temperate, terrestrial orchids. To investigate the influences of such fungi on photosynthetic, epiphytic orchids, we inoculated seedlings of Dendrobium nobile with Epulorhiza sp. (S1) or Tulasnella sp. (S3). These fungi had been identified based on their morphological and molecular characters. Both S1 and S3 formed symbiotic associations with our seedlings, promoting their growth and development to various degrees. Results from signature experiments with the 15N stable isotope suggested that the utilization of organic nitrogen by orchid seedlings was significantly improved by S1, but not by S3. Dendrobine contents were significantly higher in all inoculated seedlings. Our findings demonstrate that these mycorrhizal fungi enhance plant growth, their utilization of organic nitrogen, and the accumulation of secondary metabolites in this epiphytic orchid species.     

Taxonomy of barkeria (Orchidaceae)

The genusBarkeria (Orchidaceae) consists of four species and eight subspecies (the treatment includes a key) of epiphytic plants endemic to Mexico and Central America.Barkeria is separated from the genusEpidendrum on the structure of the rostellum and column in the flower, plus shape of the pseudobulbs. The authors suggest thatBarkeria is most closely related toCaularthron based on the general shape of the flowers, widely spreading fleshy column wings, and structure of the rostellum.     

三种药用植物内生真菌抗真菌活性的研究

从雪上一枝蒿(Aconitumbrachypodum)、刺五加(Acanthopanaxsenticosus)和大血藤(Sargentodoxacuneata)分离获得的162株内生真菌进行抗真菌活性检测,结果具有抗菌活性菌株有74株,雪上一枝蒿15株,刺五加23株,大血藤36株,分别占3种植物各自内生真菌的44.12%,48.94%和44.44%。将具有抗菌活性的菌株进行分类鉴定,分属于6目、7科、23属。     

产紫杉醇(Taxol)内生真菌的生物多样性

主要阐述了产紫杉醇内生真菌的分离和生物多样性的研究状况 ,紫杉醇产生菌的生物多样性意义及微生物发酵法生产紫杉醇的研究进展 ,并结合内生真菌的特点 ,阐述了紫杉醇产生菌的宿主、生境和生态以及物种的生物多样性     

Incompatibility in Dendrobium (Orchidaceae)

JOHANSEN, B., 1990. Incompatibility in Dendrobium (Orchidaceae). A unique self-incompatibility system in Dendrobium is demonstrated by more than 1700 pollination experiments. The majority (72%) of the 61 species that were self-pollinated showed self-sterility. In contrast with many other orchid genera Dendrobium showed high incompatibility in interspecific pollinations. Self-and interspecific incompatibility is expressed by flower abscission and not by inhibition of pollen germination or pollen tube growth. The incompatibility system is gametophytic and complementary, and it is likely that the auxin content in the pollinia triggers the incompatibility reaction. Microscopical investigations on the detached cells of the stigma (here called eleutherocytes) after compatible and incompatible pollinations, suggest that the incompatibility response is probably controlled by these cells.     

共生真菌对铁皮石斛幼苗生理特性的影响

以铁皮石斛(Dendrobium catenatum)无菌组培苗为材料,接种C20、C22、C35、C42这4株真菌菌株.共生培养60d后,研究真菌对组培苗的平均鲜重增长率、营养元素、叶绿素和内源激素的影响.结果表明:(1)接菌组培苗的营养根重分离获得原接种菌株;(2)接菌组培苗的平均鲜重增长率,叶绿素a、b含量和营养元素N、P、K含量均高于对照;(3)接菌组培苗的GA3和IAA含量均高于对照,ABA含量低于对照.其中,接种C42的组培苗平均鲜重增长率和叶绿素a含量达极显著差异(p＜0.01),接种C22和C35组培苗的平均鲜重增长率和叶绿素a含量达到显著差异(p＜0.05),接种C20和C42的组培苗K含量达显著性差异,接种C20、C35、C42的组培苗IAA含量极显著地高于对照,接菌组培苗的N含量和GA3含量均达极显著差异,而接菌组培苗的ABA含量极显著地低于对照.因此,这4株真菌菌株可应用于铁皮石斛等兰科植物的栽培与生产中.     

药用植物内生真菌及活性物质多样性研究进展

药用植物具有丰富的物种多样性,是人类生存与发展的重要自然资源。内生真菌广泛存在于健康植物组织内部,是植物微生态系统的重要组成部分,各种药用植物中蕴藏着非常丰富的内生真菌。通过与药用植物的“协同进化”,某些内生真菌具有了产生与宿主植物相同或相似的生物活性物质的能力。内生真菌产生的各种活性物质,在生物制药、农业生产、工业发酵等方面都表现出美好的应用前景,受到世界各国专家的广泛关注。利用内生真菌发酵实现生物活性物质的工业化生产,可以提高产量、降低产品成本,满足人们日益增长的需求;同时有利于珍稀、濒危药用植物资源的保护,对减少野生药用植物多样性的破坏具有重要意义。本文从药用植物内生真菌物种多样性与产生生物活性物质多样性等方面总结近年最新的研究进展,提出了内生真菌及活性物质研究的未来发展方向。     

中国石斛属一新种

Dendrobium fanjingshanense Z. H. Tsi ex X. H. Jin et Y. W. Zhang, sp. nov. Fig. 1 Habitu D. wilsonii Rolfe simile, a quo tepalis revolutis fulvis, lobo labelli intermedii infra medium macula una flabellata purpurea ornato. Epiphyticum; caulis teres, 20～40 cm altus, 2～3 mm crassus, caespitosus, superne 5～6-foliatus, internodiis 1～1.5 cm longis. Folia oblongo-lanceolata, subcoriacea, 2～5 cm longa, 5～15 mm lata, apice obtusa et plus minusve hamata, basi vaginis tubulatis membranaceis obtecta. Inflorescentiae e lateribus partium superarum caulium annotinorum defoliatorum nascentes, versus apicem caulis laterales, 1～2-florae; pedunculi 2～3 mm longi, ca. 1 mm crassi, basi vaginis 3～4 membranaceis 3～4 mm longis instructi; bracteae ovato-triangulatae, 3～5 mm longae, apice acutae, macula atro-fusca ornatae. Flores patentes; pedicelli cum ovario ca. 2～3 cm longi; tepala revoluta, fulva, apice obtusa; sepalum intermedium oblongum 2 cm longum, medio 6～7 mm latum, apice fere obtusum; sepala lateralia paulo oblique ovato-lanceolata, sepalo intermedio aequilonga sed medio paulo angustiora, apice obtusa, basi cum pede columnae mentum obconoideum ca. 8 mm longum 6 mm latum apice obtusum formantia; petala subelliptica, ca. 2 cm longa, medio 6 mm lata, apice subobtusa; labellum fulvum, basi purpureum et dense velutinum, obscure trilobatum, lobis lateralibus semiorbiculatis erectis, basi (inter lobos laterales) callo uno purpureo praeditis, lobo intermedio ovato, ca. 1 cm longo, 7 mm lato, apice subacuto et recurvo, supra medio carinato, glabro; columna alba, ca. 3 mm longa, basi in pedem ca. 9 mm longum producta, pede medio purpurato, glabro; operculum antherae album, ambitu rhombicum, glabrum; pollinia 4.     

The Diversity and Anti-Microbial Activity of Endophytic Actinomycetes Isolated from Medicinal Plants in Panxi Plateau,China

Traditional Chinese medicinal plants are sources of biologically active compounds, providing raw material for pharmaceutical, cosmetic and fragrance industries. The endophytes of medicinal plants participate in biochemical pathways and produce analogous or novel bioactive compounds. Panxi plateau in South-west Sichuan in China with its unique geographical and climatological characteristics is a habitat of a great variety of medicinal plants. In this study, 560 endophytic actinomycetes were isolated from 26 medicinal plant species in Panxi plateau. 60 isolates were selected for 16S rDNA-RFLP analysis and 14 representative strains were chosen for 16S rDNA sequencing. According to the phylogenetic analysis, seven isolates were Streptomyces sp., while the remainder belonged to genera Micromonospora, Oerskovia, Nonomuraea, Promicromonospora and Rhodococcus. Antimicrobial activity analysis combined with the results of amplifying genes coding for polyketide synthetase (PKS-I, PKS-II) and nonribosomal peptide synthetase (NRPS) showed that endophytic actinomycetes isolated from medicinal plants in Panxi plateau had broad-spectrum antimicrobial activity and potential natural product diversity, which further proved that endophytic actinomycetes are valuable reservoirs of novel bioactive compounds.     

药用植物内生真菌研究现状及其应用前景

随着对药用植物内生真菌研究的深入,从药用植物内生真菌中寻找新的生物活性成分已成为研究热点。内生真菌对药用植物的生长及活性成分的形成都有影响,内生真菌活性成分已成为发现新颖结构化合物及新药物的潜在资源。简要综述了近年来在内生真菌的分离鉴定、发酵、次生代谢产物、与宿主的关系等方面的研究进展。     

菌物药竹黄与植物药天竺黄的鉴别方法研究

为鉴别竹黄与天竺黄对菌物药竹黄与植物药天竺黄进行了性状、显微和理化鉴定方法研究。2味药在性状上差异较大;在显微鉴定中,观察了竹黄的显微结构及粉末特征,天竺黄粉末为不规则透明片状物;微量升华试验竹黄粉末随温度升高得到不同形态的结晶,而天竺黄粉末无升华物;竹黄遇KOH变为翠绿色,天竺黄则不变色;用酚酞及甲酚红试剂分别对不同来源的天竺黄进行显色反应,均显2种不同颜色。     

杜仲内生真菌的多样性分析及其抗植物病原真菌的活性

以河南郑州和江苏徐州采集到的杜仲为材料,采用纯培养方法对杜仲内生真菌进行分离。将分离纯化得到的90株真菌通过形态学鉴定并进行多样性分析,90株内生真菌分别属于13个属,其中茎点霉属(Phoma)和链格孢属(Alternaria)为优势菌群,分别占总菌株数的18%和16%;其次为黑孢属(Nigrospora)和枝孢属(Cladosporium),均占总菌株数的10%。用平板对峙法对分离得到的杜仲内生真菌进行抗植物病原真菌实验,发现有18个菌株对至少一种病原真菌具有明显的拮抗作用。通过比色法进行内生真菌产IAA(吲哚乙酸)定性实验,结果显示,有37株真菌具有产IAA能力,通过分光光度法对这37株真菌进行产IAA定量实验,发现有8株有较好的产IAA活性。     

美花石斛菌根真菌接菌方式与接种效应初步研究

自然条件下,兰科菌根真菌的共生对于兰科植物种子萌芽和植株生长是必不可少的。为探讨有益共生真菌对兰科植物生长的促进作用,特别是在实验室环境下接菌方式的改变与接种效应直接的联系,本研究从野生美花石斛(Dendrobium loddigesii Rolfe.)新鲜营养根中分离、筛选出3种菌根真菌（M1、M2和M3）,采用单一接菌和混合接菌的接种方式,分析3个菌株及其不同接种方式对美花石斛生长的影响。研究得到优势菌株M1和M3,并证实混合接菌对美花石斛的生物量增长具有较好的正效应,两两混合接种方式M1-M2、M2-M3及3个混合接种方式M1-M2-M3均能较好的促进美花石斛生物量的积累。充分发挥混合接菌对兰科植物生长发育所产生的效能,提高生产效率,具有较强的现实意义。