Large-Scale Screening of the Plant Extracts for Antifungal Activity against the Plant Pathogenic Fungi

Plants produce chemicals of immense diversity that provide great opportunities for development of new antifungal compounds. In search for environment-friendly alternatives to the fungicide of current use, we screened plant extracts obtained from more than eight hundred plant materials collected in Korea for their antifungal activity against the model plant pathogenic fungus, Magnaporthe oryzae. This initial screening identified antifungal activities from the eleven plant extract samples, among which nine showed reproducibility in the follow-up screening. These nine samples were able to suppress not only M. oryzae but also other fungal pathogens. Interestingly, the plant extracts obtained from Actinostemma lobatum comprised five out of eight samples, and were the most effective in their antifungal activity. We found that butanol fraction of the A. lobatum extract is the most potent. Identification and characterization of antifungal substances in the A. lobatum extracts would provide the promising lead compounds for new fungicide.     

Antifungal Activities of Four Fatty Acids against Plant Pathogenic Fungi

The effect of the fatty acids linolenic acid, linoleic acid, erucic acid and oleic acid on the growth of the plant pathogenic fungi Rhizoctonia solani, Pythium ultimum, Pyrenophora avenae and Crinipellis perniciosa were examined in in vitro studies. Linolenic and linoleic acids exhibited activity against all of the fungi. However, whereas linolenic acid reduced mycelial growth of R. solani and C. perniciosa at 100 microM, the concentration had to be increased to 1000 microM before any effect on mycelial growth of P. ultimum and P. avenae was observed. Linoleic acid only reduced mycelial growth of R. solani, P. ultimum and P. avenae at 1000 microM, but led to a significant reduction in growth of C. perniciosa at 100 microM. In contrast, oleic acid had no significant effect on growth of R. solani or P. avenae, but gave significant reductions in mycelial growth of P. ultimum at 100 microM and reduced growth of C. perniciosa significantly at 1000 microM. All of the fatty acids reduced biomass production by all of the fungi significantly in liquid culture when added to the media at 100 microM. Erucic acid had no effect on fungal growth at any concentration examined. The antifungal activities exhibited by linolenic, linoleic and oleic acids may be useful in the search for alternative approaches to controlling important plant pathogens, such as those examined in this study.     

枯草芽孢杆菌TF26抗菌蛋白抑菌活性的初步研究

目的:研究枯草芽孢杆菌TF26抗菌蛋白的抑菌活性和生物稳定性,为菌株及抗菌蛋白的应用提供理论依据.方法:采用硫酸铵盐析方法提取抗菌蛋白,采用菌丝生长速率法检测其对13种植物病原真菌的抑菌活性,采用抑菌圈方法对其生物稳定性进行分析.结果:抗菌蛋白粗提物能够抑制13种植物病原真菌的生长,平皿抑制率为74.3％ ～91.3％,对葵花菌核病菌、番茄和黄瓜枯萎病菌、黄瓜菌核病菌和立枯病菌、水稻恶苗病菌和大豆根腐病菌抑制作用较强.抗菌蛋白在100℃以下,pH＜ 10范围内抑菌活性稳定,对紫外线照射不敏感,室温(20℃)和4℃储存150d抑菌活性稳定.结论:抗菌蛋白具有较强的热、酸碱、紫外和储存稳定性以及广谱的抑菌活性.     

迷迭香酸对几种植物病原真菌的抗菌活性*

研究了迷迭香酸对不同植物病原真菌菌丝生长和孢子萌发的抑制活性。试验结果表明,迷迭香酸对供试的8种植物病原真菌菌丝生长均有抑制作用,其中对番茄灰霉病菌、芒果灰斑病菌、柑桔青霉和梨黑斑病菌抑制作用较强,EC50分别为615．04μg/mL、698．23μg/mL、714．50μg/mL和809．10μg/mL;对杉木猝倒病菌和苹果树腐烂病菌抑制作用次之,EC50分别为1039．92μg／mL和1044．72μg/mL;对松枯梢病菌和种实霉烂病菌的抑制作用较弱,EC50分别为1256．90μg/mL和1270．87μg/mL。迷迭香酸对供试的6种植物病原真菌孢子萌发也有明显的抑制作用,EC50大致在400～700μg/mL范围,其中对梨黑斑病菌孢子萌发抑制作用最强,EC50为395．37μg/mL。     

藓类提取物对植物病原真菌的抑菌性研究

以立枯丝核菌(Rhizoctonia)、尖孢镰孢菌(Fusarium oxysporum)、苹果轮纹病菌(Macrophoma kawatsukai)、梨黑星病菌(Fusicladium pirina)、草莓灰霉菌(Botrytis cinerea)等七种植物病原真菌为供试菌,通过生长速率法测定了24种藓类的乙醇提取物对病原真菌的抑制作用.结果表明,在提取物浓度为1.2mg干样/mL,大镰刀藓提取物对立枯丝核菌的抑制作用最强,抑菌率为67.8%.藓类提取物不仅对植物病原真菌有抑菌活性,而且还有多种藓类提取物对病原真菌菌丝有促进生长活性,如锐尖匍灯藓对立枯丝核菌菌丝生长的促进率为95.1%.选出大镰刀藓、扁灰藓、紫萼藓、山地水灰藓、疣小金发藓、橙色净口藓、锐尖匍灯藓和羊角藓对立枯丝核菌和灰霉菌的抑菌性或菌丝生长促进性进行了进一步研究,藓类提取物对病原菌的抑菌性或菌丝生长促进性在一定范围内随浓度的增加而增强,并且抑菌性随时间的延长呈下降趋势.     

11种植物精油对6种植物病原真菌的抑菌活性研究

为筛选有效的植物杀菌成分,采用菌丝生长法,测定了香茅油、薰衣草油、菊花油、月桂油、柠檬油、广藿香油、肉桂油、天竺葵油、迷迭香油、茶树油、薄荷油对6种植物病原真菌的抑菌活性。发现在2 g/L的浓度下,上述11种精油对6种供试病菌均有明显的抑制作用,其中香茅油、肉桂油、天竺葵油、月桂油、茶树油和薄荷油对6种病原真菌的抑制率均为100%。剂量效应试验表明,肉桂油对灰葡萄孢（Botrytis cinerea）和禾谷镰孢菌（Fusariumgraminearum）的EC50值分别为29.05μg/mL和42.96μg/mL,而天竺葵油对灰葡萄孢（Botrytis cinerea）和禾谷镰孢菌（Fusarium graminearum）的EC50值分别为34.02μg/mL和68.48μg/mL。     

植物精油抑菌活性研究进展

本文综述了国内外植物精油在农用抑菌活性及抑菌活性成分研究方面所取得的成果。阐述了具有农用抑菌活性的31种植物精油及其抑菌效果,并列举了植物精油中13种具有开发潜力的抑菌活性成分,简要分析了植物精油及其主要活性成分的作用机理。     

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。     

小桐子枝叶提取物对植物病原真菌的生物活性

采用菌丝生长抑制法,测定了小桐子枝叶6种不同溶剂提取物对小麦赤霉病菌、稻瘟病菌、烟草疫霉菌和辣椒疫霉菌的抑制作用,从中筛选出抑制作用最强的粗提物进行进一步的活性组分分离和抑菌活性测定。结果表明小桐子枝叶的乙醇提取物对4种植物病原菌抑制活性最高,在浓度为0.8 g·L^-1时,小桐子枝叶的乙醇提取物对小麦赤霉病菌、稻瘟病菌、烟草疫霉菌、辣椒疫霉菌菌丝生长抑制率分别为：87.1%、90.3%、86.4%、77.9%,其抗菌活性与农药世高均无显著差异;在小桐子枝叶乙醇提取物的不同溶剂萃取物对稻瘟病菌和烟草疫霉病菌进行生物活性追踪测试中发现,石油醚和水萃取物都具有较好的活性,当浓度为0.8 g·L^-1时,石油醚和水萃取物对两种病菌抑制率都达50%以上。表明小桐子枝叶含有丰富的抗植物病原真菌活性物质,且主要存在于小桐子枝叶乙醇提取物的石油醚相和水相中。     

Antifungal Activity of Cadinane-Type Sesquiterpenes from Eupatorium adenophorum against Wood-Decaying Fungi

The present study aimed to evaluate the antifungal activities of Eupatorium adenophorum against four strains of wood-decaying fungi, including Inonotus hispida, Inonotus obliquus, and Inonotus cuticularis. Bioguided isolation of the methanol extract of E. adenophorum by silica gel column chromatography and high-performance liquid chromatography afforded six cadinane-type sesquiterpenes. Their structures were identified by nuclear magnetic resonance and MS analyses. According to the antifungal results, the inhibition rate of the compound was between 59.85 % and 77.98 % at a concentration of 200 μg/mL. The EC₅₀ values ranged from 74.5 to 187.4 μg/mL.     

小桐子内生真菌及其抗真菌活性研究

从药用植物小桐子的根和茎中分离到内生真菌57株,经鉴定,它们分属于15个不同的分类单元。其中拟盘多毛孢为优势属,其次为拟茎点霉属和茎点霉属。用杨桃炭疽菌,香蕉疫霉和镰刀菌作指示菌对这些内生真菌的抗真菌活性进行检测,结果表明,有2株菌对杨桃炭疽菌具有抑菌活性。     

多孔板-MTT比色法评价植物和微生物代谢产物的抗真菌活性

多孔板-MTF比色法测定植物和微生物代谢产物对真菌抑制活性的步骤为:在多孔板的每孔中依次加入浓度为105孢子/mL的供试真菌孢子悬液90μL,不同浓度的药液10 μL.25℃暗培养48 h,然后每孔中加入8mg/mL的MTT溶液10μL,继续培养10 h后,离心去上清,加入DMS0 150 μL,振荡30 min,离心后上清液在510nm测定吸光值.采用上述条件测定了白屈菜红碱对稻瘟病菌和西瓜枯萎病菌的MIC值分别为80和1.5μg/mL,IC50值分别为21.99和0.78 μg/mL;Diepoxinζ对稻瘟病菌的MIC和IC50值分别为200和96.21 μg/mL.多孔板-MTT比色法为快速有效地筛选和评价植物和微生物抗真菌活性成分创造了条件.     

侧柏乙醇提取物对21种植物病原真菌的抑菌活性

采用菌丝生长速率法测定了侧柏(Platycladus orientalis)叶、小枝、球果和种子4个不同部位乙醇提取物对21种植物病原真菌的抑菌活性。结果显示:(1)在供试浓度为50g/L(相当于干样)时,侧柏各部位乙醇提取物对4种供试植物病原真菌均具有较好抑制作用,其中侧柏叶提取物的抑菌效果最好,对供试葡萄白腐病菌(Conio-thyrium diplodiella)、葡萄黑痘病菌(Elsinoe ampelina)、番茄绵腐病菌(Phytophthora melongenae)和青霉病菌(Penicilliu mexpansum)的EC50分别为:5.424、3.186、8.913和19.000g/L。(2)侧柏叶乙醇提取物的石油醚萃取物和乙酸乙酯萃取物抑菌活性均较好,在供试浓度为0.5g/L时,石油醚萃取物对苹果腐烂病菌(Valsa mali)和葡萄黑痘病菌(E.ampelina)的抑菌率分别为80.35%和60.23%;乙酸乙酯萃取物对以上2种植物病原菌的抑菌率分别为81.88%和64.06%。结果表明:侧柏叶、小枝、球果和种子乙醇提取物均具有一定抑菌活性,叶乙醇提取物的活性最好,活性成分主要集中在石油醚萃取物和乙酸乙酯萃取物中。     

真菌诱导的植物几丁酶蛋白

几丁酶,水解几丁质-真菌细胞壁的主要成分,该酶广泛存在于微生物和动植物中.近年来,植物几丁酶在植物抗真菌侵染过程中的作用和巨大的应用前景,已引起了人们的广泛关注.重点综述亲和组合、不亲和组合及内生菌根中真菌对植物几丁酶蛋白的诱导、几丁酶的组织细胞学定位及其抗真菌活性研究.     

卷叶黄精对植物病原菌的抗菌活性研究

采用菌丝生长速率法研究了卷叶黄精根提取物对植物病原菌的抗菌活性。结果表明:卷叶黄精对所选10种植物病原菌中的7种呈现不同程度的抗菌活性,而且各萃取物的抑菌菌种各不相同,其中正丁醇萃取物对4种病原菌、乙酸乙酯萃取物对3种病原菌有明显的抑菌活性,水浓缩物仅对1种病原菌有抗菌活性,而石油醚萃取物对供试植物病原菌没有抗菌活性;正丁醇萃取物对苹果褐腐病、玉米大斑病、棉黄萎病病原菌抑制作用较强,EC50分别为261.26、376.03和430.05μg.mL-1;乙酸乙酯萃取物对苹果腐烂病、番茄黑霉病病原菌抑制作用较强,EC50分别为386.00和865.75μg.mL-1,各样品对植物病原菌的毒力随着浓度的增高而增强;卷叶黄精对植物病原菌的抑菌活性随着作用时间的延长,均呈现不同的下降趋势。     

Latent Pathogenic Fungi in the Medicinal Plant Houttuynia cordata Thunb. Are Modulated by Secondary Metabolites and Colonizing Microbiota Originating from Soil

Latent pathogenic fungi (LPFs) affect plant growth, but some of them may stably colonize plants. LPFs were isolated from healthy Houttuynia cordata rhizomes to reveal this mechanism and identified as Ilyonectria liriodendri, an unidentified fungal sp., and Penicillium citrinum. Sterile H. cordata seedlings were cultivated in sterile or non-sterile soils and inoculated with the LPFs, followed by the plants’ analysis. The in vitro antifungal activity of H. cordata rhizome crude extracts on LPF were determined. The effect of inoculation of sterile seedlings by LPFs on the concentrations of rhizome phenolics was evaluated. The rates of in vitro growth inhibition amongst LPFs were determined. The LPFs had a strong negative effect on H. cordata in sterile soil; microbiota in non-sterile soil eliminated such influence. There was an interactive inhibition among LPFs; the secondary metabolites also regulated their colonization in H. cordata rhizomes. LPFs changed the accumulation of phenolics in H. cordata. The results provide that colonization of LPFs in rhizomes was regulated by the colonizing microbiota of H. cordata, the secondary metabolites in the H. cordata rhizomes, and the mutual inhibition and competition between the different latent pathogens.     

基于代谢组学技术的植物抗病相关代谢物研究进展

植物受到病原真菌侵染时往往通过调节体内代谢物的产生来增强自身抗性,代谢组学技术是研究植物抗病相关代谢物的重要工具.指认植物抗病相关代谢物不仅利于深入探讨其抗病机制,还可与其他组学技术结合,辅助抗性品种鉴定和抗病品种培育.该研究对近年来国内外有关基于代谢组学技术指认植物抗病相关代谢物的流程、已发现的抗病相关代谢物及其作用...     

Fungicidal Activity of Some Common Weed Extracts Against Different Plant Pathogenic Fungi

Aqueous extract effects of 64 weed species on growth and development of Alternaria solani Sorauer. Helminthosporium satirum King & Bakke and Rhizodonia solani Kuhn. plant pathogenic fungi were studied in vitro . Extracts varied in the strength and persistence of their antifungal effects against the three fungi species. Some stimulated, others inhibited or had no effect. Among all species tested, extracts of Chenopodium murale, Falearia vulgaris. Ranunculus asiaticus and Sisymbrium irio were the most toxic to A. solani. Anagallis arlensis. Atriptex leucoclada, Crepis aspera. Notobasis syriaca. R. asiatieus, Rumex crispu. S. irio. Sonehu.s oleraceous and Vieia narhonensis to H. satirum and R. asiatieus. S. oleraceous and Mercurialis annua to R. solani. However. R. asiatieus extract was the most effective and completely inhibited growth and sporulation of the three fungi species at all incubation periods.     

三种苔藓植物提取物对植物病原菌的抑菌性研究

以立枯丝核菌(Rhizoctoniasolani)、棉花枯萎病菌(Fusariumoxysporum)、苹果轮纹病菌(Physalosporapiricolanosa)、草莓灰霉病菌(Botrytiscinerea)四种植物病原菌为供试病原菌,对大镰刀藓Drepanocladusexannulatus、锐尖匍灯藓Plagiomniumacutum和疣小金发藓Pogonatumurnigerum三种藓类醇提液进行抑菌活性筛选,结果表明,大镰刀藓提取液对立枯丝核菌有较好的抑制作用,对立枯丝核菌的EC50为0.878mg/mL;而锐尖匍灯藓的提取液对立枯丝核菌的生长却有促进作用。     

植物病原真菌广谱拮抗菌的筛选鉴定及发酵条件初步研究

通过对峙培养法筛选到对8种植物病原真菌具有拮抗作用的芽孢杆菌菌株,通过测量10-30℃下的抑菌圈直径发现AFB037菌株在不同温度下抑菌效果最好。通过表型和16S rDNA序列分析将AFB037菌株鉴定为多粘类芽孢杆菌。AFB037菌株抗菌成分的产生需要真菌菌体成分的诱导,提示其有效成分可能为细胞壁降解酶类。