Ginsenosides as host resistance factors in American ginseng (Panax quinquefolius)

2002 ◽  
Vol 80 (5) ◽  
pp. 557-562 ◽  
Author(s):  
R W Nicol ◽  
J A Traquair ◽  
M A Bernards

American ginseng (Panax quinquefolius L.) produces a number of saponins (ginsenosides). The ability of saponins from cultivated American ginseng to inhibit fungal growth in vitro was evaluated. Fungi exhibited a range of sensitivity to ginsenosides extracted from roots collected in two growing seasons. Important root pathogens (Cylindro carpon destructans, Fusarium solani, and Fusarium oxysporum) were unaffected by these phytochemicals at a concentration of 1 mg·mL–1, whereas the growth of Alternaria panax and nonpathogenic Trichoderma spp. was inhibited. The same trend emerged when a range of ginsenoside concentrations was used on a subset of fungi. Hyphal growth of C. destructans was unaffected up to a level of ginsenosides approaching that found in roots (i.e., ~ 3% dry weight). The growth of F. solani was significantly less than that of the control at saponin concentrations of 0.1 to 3.0% (w/v), but was relatively unaffected in comparison to growth of Trichoderma hamatum and A. panax.Key words: ginsenoside, antifungal, pathogenic fungi, disease resistance, phytochemicals.

1999 ◽  
Vol 65 (3) ◽  
pp. 1320-1324 ◽  
Author(s):  
Zhi-Yuan Chen ◽  
Robert L. Brown ◽  
Alan R. Lax ◽  
Thomas E. Cleveland ◽  
John S. Russin

ABSTRACT The cDNA of a 14-kDa trypsin inhibitor (TI) from corn was subcloned into an Escherichia coli overexpression vector. The overexpressed TI was purified based on its insolubility in urea and then refolded into the active form in vitro. This recombinant TI inhibited both conidium germination and hyphal growth of all nine plant pathogenic fungi studied, including Aspergillus flavus,Aspergillus parasiticus, and Fusarium moniliforme. The calculated 50% inhibitory concentration of TI for conidium germination ranged from 70 to more than 300 μg/ml, and that for fungal growth ranged from 33 to 124 μg/ml depending on the fungal species. It also inhibited A. flavus and F. moniliforme simultaneously when they were tested together. The results suggest that the corn 14-kDa TI may function in host resistance against a variety of fungal pathogens of crops.


2013 ◽  
Vol 13 (2) ◽  
pp. 117-123 ◽  
Author(s):  
Loekas Soesanto ◽  
Endang Mugiastuti ◽  
Ruth Feti Rahayuniati ◽  
Ratna Stia Dewi

Compatibility test of four Trichoderma spp. Isolates and in vitro inhibition ability on several plant pathogens. In vitro descriptive compatibility research was carried out to know the compatibility among Trichoderma spp. isolates and their inhibition ability toward several plant pathogens. Four Trichoderma spp. isolates used were ginger, shallot, banana, and pineapple isolates; while the pathogens used were pathogenic fungi (Fusarium, Colletotrichum, Phytophthora, and Sclerotium), bacteria (Ralstonia), and nematode (Meloidogyne dan Globodera). Observation was done toward inhibition zone between Trichoderma spp. isolates, colony radial growth, mycelial dry weight, and nematode mortality. Result of the research indicated that the four Trichoderma spp. isolates were compatible and no growth inhibition was observed. The inhibition ability of all Trichoderma spp. isolates varied and the ginger isolate had the highest inhibition ability and mortality on all fungal species and the nematodes, while on the pathogenic bacteria there was no inhibition.


Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 737
Author(s):  
Marina Pekmezovic ◽  
Melina Kalagasidis Krusic ◽  
Ivana Malagurski ◽  
Jelena Milovanovic ◽  
Karolina Stępień ◽  
...  

Novel biodegradable and biocompatible formulations of “old” but “gold” drugs such as nystatin (Nys) and amphotericin B (AmB) were made using a biopolymer as a matrix. Medium chain length polyhydroxyalkanoates (mcl-PHA) were used to formulate both polyenes (Nys and AmB) in the form of films (~50 µm). Thermal properties and stability of the materials were not significantly altered by the incorporation of polyenes in mcl-PHA, but polyene containing materials were more hydrophobic. These formulations were tested in vitro against a panel of pathogenic fungi and for antibiofilm properties. The films containing 0.1 to 2 weight % polyenes showed good activity and sustained polyene release for up to 4 days. A PHA monomer, namely 3-hydroxydecanoic acid (C10-OH), was added to the films to achieve an enhanced synergistic effect with polyenes against fungal growth. Mcl-PHA based polyene formulations showed excellent growth inhibitory activity against both Candida yeasts (C. albicans ATCC 1023, C. albicans SC5314 (ATCC MYA-2876), C. parapsilosis ATCC 22019) and filamentous fungi (Aspergillus fumigatus ATCC 13073; Trichophyton mentagrophytes ATCC 9533, Microsporum gypseum ATCC 24102). All antifungal PHA film preparations prevented the formation of a C. albicans biofilm, while they were not efficient in eradication of mature biofilms, rendering them suitable for the transdermal application or as coatings of implants.


2014 ◽  
Vol 40 (2) ◽  
pp. 141-146 ◽  
Author(s):  
Zayame Vegette Pinto ◽  
Matheus Aparecido Pereira Cipriano ◽  
Amaury da Silva dos Santos ◽  
Ludwig Heinrich Pfenning ◽  
Flávia Rodrigues Alves Patrício

Bottom rot, caused by Rhizoctonia solani AG 1-IB, is an important disease affecting lettuce in Brazil, where its biological control with Trichoderma was not developed yet. The present study was carried out with the aim of selecting Trichoderma isolates to be used in the control of lettuce bottom rot. Forty-six Trichoderma isolates, obtained with baits containing mycelia of the pathogen, were evaluated in experiments carried out in vitro and in vivo in a greenhouse in two steps. In the laboratory, the isolates were evaluated for their capabilities of parasitizing and producing toxic metabolic substances that could inhibit the pathogen mycelial growth. In the first step of the in vivo experiments, the number and the dry weight of lettuce seedlings of the cultivar White Boston were evaluated. In the second step, 12 isolates that were efficient in the first step and showed rapid growth and abundant sporulation in the laboratory were tested for their capability of controlling bottom rot in two repeated experiments, and had their species identified. The majority of the isolates of Trichoderma spp. (76%) showed high capacity for parasitism and 50% of them produced toxic metabolites capable of inhibiting 60-100% of R. solani AG1-IB mycelial growth. Twenty-four isolates increased the number and 23 isolates increased the dry weight of lettuce seedlings inoculated with the pathogen in the first step of the in vivo experiments.In both experiments of the second step, two isolates of T. virens, IBLF 04 and IBLF 50, reduced the severity of bottom rot and increased the number and the dry weight of lettuce seedlings inoculated with R. solani AG1-IB. These isolates had shown a high capacity for parasitism and production of toxic metabolic substances, indicating that the in vitro and in vivo steps employed in the present study were efficient in selecting antagonists to be used for the control of lettuce bottom rot.


Author(s):  
Anam Choudhary ◽  
Shabbir Ashraf

AbstractThe present study was carried out to evaluate the effect of bioagents and organic amendments in suppressing the dry root rot of mungbean incited by Rhizoctonia bataticola. The locally isolated pathogen and fungal biocontrol agents were identified based on morphological and molecular characterization. These identified bioagents were tested in vitro, and the highest mycelial inhibition was recorded in dual culture assay by Trichoderma harzianum (74.44%), and among organic amendments, maximum mycelial inhibition was found in neem cake (61.11%). In a greenhouse study, T. harzianum + neem cake effectively enhanced the percent germination (93.33%) and decreased the percent disease mortality (11.67%) than the other treatments. The morphological parameter like plant height (57.50 cm), dry weight (22.83 g) root nodules (51), pods/plant (58), and 100-seed weight (5.78 g) were found to be at the maximum in this combined application. Physiological pigments viz. chlorophyll (2.41 mg/g) and carotenoids (0.19 mg/g), protein content (5.85 mg/g), and leghemoglobin (11.75 mg/g) were also found to be maximum in T. harzianum + neem cake and minimum phenol content (1.41 mg/g). The study concludes that T. harzianum + neem cake can be recommended as an effective approach for the management of dry root rot of mungbean.


2013 ◽  
Vol 50 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Ewa Kochan ◽  
Aleksander Chmiel

Abstract:Asian ginseng (Panax ginseng) and American ginseng (P. quinquefolius) are valuable medicinal herbs whose roots have been used for ages in traditional medicine in China and North America as vitalizing and stimulating agents. The roots are obtained mainly from field cultivation, which is a slow (5-7 years long), laborious, and troublesome process; so in vitro methods started to be used to produce ginseng biomass. In our study, non-organogenic callus of P. quinquefolius synthesized the same active substances like field roots, for more than 6 years. The ginsenosides are derivatives of protopanaxadiol (Rb1, Rb2, Rc, Rd) or protopanaxatriol (Rg1, Re). The synthesis of Rg1and Re metabolites is preferred in calli cultured in the dark and with ageing of culture.


2010 ◽  
Vol 59 (2) ◽  
pp. 200-205 ◽  
Author(s):  
Ildikó Nyilasi ◽  
Sándor Kocsubé ◽  
Miklós Pesti ◽  
Gyöngyi Lukács ◽  
Tamás Papp ◽  
...  

The in vitro antifungal activities of primycin (PN) and various statins against some opportunistic pathogenic fungi were investigated. PN completely inhibited the growth of Candida albicans (MIC 64 μg ml−1) and Candida glabrata (MIC 32 μg ml−1), and was very effective against Paecilomyces variotii (MIC 2 μg ml−1), but had little effect on Aspergillus fumigatus, Aspergillus flavus or Rhizopus oryzae (MICs >64 μg ml−1). The fungi exhibited different degrees of sensitivity to the statins; fluvastatin (FLV) and simvastatin (SIM) exerted potent antifungal activities against a wide variety of clinically important fungal pathogens. Atorvastatin, rosuvastatin and lovastatin (LOV) had a slight effect against all fungal isolates tested, whereas pravastatin was completely ineffective. The in vitro interactions between PN and the different statins were investigated using a standard chequerboard titration method. When PN was combined with FLV, LOV or SIM, both synergistic and additive effects were observed. The extent of inhibition was higher when these compounds were applied together, and the concentrations of PN and the given statin needed to block fungal growth completely could be decreased by several dilution steps. Similar interactions were observed when the variability of the within-species sensitivities was investigated.


Botany ◽  
2009 ◽  
Vol 87 (4) ◽  
pp. 387-400 ◽  
Author(s):  
Christine Juge ◽  
Annie Champagne ◽  
Andrew P. Coughlan ◽  
Nicolas Juge ◽  
Lael Parrott ◽  
...  

The present study is, to the best of our knowledge, the first to investigate the use of the fractal dimension (FD) to quantify the growth and development of undisturbed, fully functional arbuscular mycorrhizal (AM) hyphae developing in vitro. The majority of the work focused on the model AM fungus Glomus intraradices DAOM 181602. The time course study and final measurements of an intact mature extraradical mycelium allowed us to compare the development of the mycelium and the FD value. The final FD value of 1.62 for the mature mycelium is similar to that obtained for highly branched root systems and tree crowns. The FD method was used to characterize the morphology of germinative and presymbiotic hyphae in the presence of stimulatory (strigolactone GR-24, 0.1 µmol·L–1 and bisphenol A, 10 µmol·L–1) and inhibitory (NaCl, 80 mmol·L–1) molecules, and the extraradical phase in the presence of an inhibitory molecule (NaCl, 80 mmol·L–1). Where possible, results were compared with those obtained using the traditional grid-line (GL) technique. The FD approach allowed treatment effects to be accurately quantified, both in germinative and extraradical phases. In the second case, this technique provided a single quantitative value of extraradical hyphal growth that included runner hyphae (RH) networks, and fine-branching (FB) ramifications. This is in contrast to the GL technique, which provides a value for the estimation of RH, but which is not suitable for accurately measuring FB hyphae. Given the ease with which the FD values can be calculated, and the fact that this method can provide a single value for the quantification of extraradical hyphal growth and development, we suggest that this method is useful for in vitro studies. Furthermore under certain situations of germinative or presymbiotic growth, it may be used in concert with the GL method to provide a greater degree of information about hyphal morphology. The usefulness and limits of the FD method at different stages of the AM fungal growth cycle are discussed.


2021 ◽  
Vol 3 (12) ◽  
Author(s):  
David Lowes ◽  
Rand Al-waqfi ◽  
Kirk Hevener ◽  
Brian Peters

Due to structural similarities that exist between established inhibitors of the NLRP3-inflammasome, sulfonylureas Glyburide and MCC-950, and herbicidal-sulfonylureas, that specifically target fungal acetohydroxyacid synthase (AHAS), we sought to determine the potential for compounds to block both inflammation and inhibit fungal growth. In silico screening of ∼250,000 compounds was used to identify a prioritized list of chemical structures capable of inhibiting both targets. Prioritization of the top 1% of scores identified ∼70 compounds with a diverse set of scaffolds for testing in vitro. Selected hits were used to assess anti-inflammatory function in a THP-1 challenge model with LPS+ATP and resulting IC50 values were obtained. MIC and hyphal-growth assays were conducted to determine potential antifungal activity using media depleted of branched chain amino acids isoleucine and valine, to confirm on target AHAS inhibition. Identification of hits that exhibited low micromolar activity for NLRP3 and AHAS inhibition were selected for SAR study. In vitro testing of the analogs along with molecular docking led to increased knowledge for lead optimization of the potential hits. In silico screening has resulted in IC50 (IL-1β release) and MIC50 (fungal growth) values with low μM potency against several Candida species. In vivo validation will further confirm the potential of the scaffolds for further synthetic-modification for the rationale design of novel dual-purpose drugs


2009 ◽  
Vol 2009 ◽  
pp. 174-174
Author(s):  
M H Sakhavati ◽  
T Mohammadabadi ◽  
M Danesh Mesgaran ◽  
M R Nassiry ◽  
A Fani Maleki

Rumen fungi produce a wide range of polysaccharide degrading enzymes during growth on cell walls and can degrade 0.25 -0.65 of plant tissue dry weight in pure cultures (Orpin, 1983). It has been proposed that sodium hydroxide may break-down hemicellulose and cellulose and expose them to microbial attachment and improve digestibility (Gotoet al., 1993). The aim of the present study was to determinein vitrorumen fungal growth using a quantitative competitive PCR assay (QC-PCR) and dry matter (DM) and neutral detergent fibre (NDF) disappearance from a medium containing untreated (US) or sodium hydroxide treated wheat straw (TS).


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