scholarly journals The effect of chitosan on limitation of growth and development of some pathogenic fungi for ornamental plants

2013 ◽  
Vol 54 (1) ◽  
pp. 17-29 ◽  
Author(s):  
Alicja Saniewska
Keyword(s):  
Fusarium Oxysporum ◽  
Inhibitory Action ◽  
Marked Effect ◽  
Ornamental Plants ◽  
Pathogenic Fungi ◽  
Inhibitory Effect ◽  
Crab Shell ◽  
Necrotic Spots ◽  
Tulip Bulbs

The inhibitory effect of crab-shell chitosan, medium (200-800 cps) and high molecular weight ( 800-2000 cps) (purchased from Sigma-Aldrich Chemicals) toward <i>Alternaria alternata, Botrytis tulipae, Fiisarium oxysporum</i> f. sp. <i>callistephi, Fusarium oxysporum</i> f. sp. <i>tulipae, Phoma narcissi</i> and <i> Phoma poolensis</i> was evaluated <i>in vitro</i> and in <i>vivo</i>. The chitosan evidently inhibited in vitro growth of all tested pathogens, with a marked effect at higher concentrations above 200 μg/cm<sup>3</sup>. Chitosan at a concentration of 1,25; 2,5 and 5,0 mg/cm<sup>3</sup> didn't have inhibitory action in appearance of fungi growth on naturally contaminated <i>Callistephus chinensis</i> seeds. At the same concentrations, chitosan applied as bulb scales dressing of <i>Hymenocallis narcissiflora</i> bulbs, before inoculation or after inoculation with <i>Phoma narcissi</i>, inhibited the development of necrotic spots on scales. Chitosan used preventively or curatively at a concentrations of 1,25; 2,5 and 5,0 mg/cm<sup>3</sup> indicated inhibitory effect on development of <i>Fusarium oxysporum</i> f. sp. <i>tulipae</i> on tulip bulbs. Chitosan at a concentration of 10 mg/cm<sup>3</sup> applied preventively (first spray 12th June) was very effective in the control of <i>Puccinia antirrhini</i> on snapdragon in the field. The strongest inhibitory effect was observed on snapdragon treated 8 times at week intervals.

scholarly journals Antagonistic Activity of Trichoderma spp. Against Fusarium oxysporum in Rhizosphere of Radix pseudostellariae Triggers the Expression of Host Defense Genes and Improves Its Growth Under Long-Term Monoculture System

2021 ◽  
Vol 12 ◽  
Author(s):  
Jun Chen ◽  
Liuting Zhou ◽  
Israr Ud Din ◽  
Yasir Arafat ◽  
Qian Li ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Fungal Pathogens ◽  
Pathogenic Fungi ◽  
Inhibitory Effect ◽  
Pcr Analysis ◽  
Defense Genes ◽  
Trichoderma Spp ◽  
Antagonistic Microorganisms

Under consecutive monoculture, the abundance of pathogenic fungi, such as Fusarium oxysporum in the rhizosphere of Radix pseudostellariae, negatively affects the yield and quality of the plant. Therefore, it is pertinent to explore the role of antagonistic fungi for the management of fungal pathogens such as F. oxysporum. Our PCR-denatured gradient gel electrophoresis (DGGE) results revealed that the diversity of Trichoderma spp. was significantly declined due to extended monoculture. Similarly, quantitative PCR analysis showed a decline in Trichoderma spp., whereas a significant increase was observed in F. oxysporum. Furthermore, seven Trichoderma isolates from the R. pseudostellariae rhizosphere were identified and evaluated in vitro for their potentiality to antagonize F. oxysporum. The highest and lowest percentage of inhibition (PI) observed among these isolates were 47.91 and 16.67%, respectively. In in vivo assays, the R. pseudostellariae treated with four Trichoderma isolates, having PI &gt; 30%, was used to evaluate the biocontrol efficiency against F. oxysporum in which T. harzianum ZC51 enhanced the growth of the plant without displaying any disease symptoms. Furthermore, the expression of eight defense-related genes of R. pseudostellariae in response to a combination of F. oxysporum and T. harzianum ZC51 treatment was checked, and most of these defense genes were found to be upregulated. In conclusion, this study reveals that the extended monoculture of R. pseudostellariae could alter the Trichoderma communities in the plant rhizosphere leading to relatively low level of antagonistic microorganisms. However, T. harzianum ZC51 could inhibit the pathogenic F. oxysporum and induce the expression of R. pseudostellariae defense genes. Hence, T. harzianum ZC51 improves the plant resistance and reduces the growth inhibitory effect of consecutive monoculture problem.

Mechanism of the Antiplatelet Action of Dipyridamole in Whole Blood: Modulation of Adenosine Concentration and Activity

1986 ◽  
Vol 55 (01) ◽  
pp. 012-018 ◽  
Author(s):  
Paolo Gresele ◽  
Jef Arnout ◽  
Hans Deckmyn ◽  
Jos Vermylen
Keyword(s):  
Platelet Aggregation ◽  
Adenosine Receptor ◽  
Whole Blood ◽  
Blood Cells ◽  
Inhibitory Action ◽  
Phosphodiesterase Inhibitor ◽  
Inhibitory Effect ◽  
Adenosine Concentration ◽  
Pharmacological Studies

SummaryDipyridamole inhibits platelet aggregation in whole blood at lower concentrations than in plasma. The blood cells responsible for increased effectiveness in blood are the erythrocytes. Using the impedance aggregometer we have carried out a series of pharmacological studies in vitro to elucidate the mechanism of action of dipyridamole in whole blood. Adenosine deaminase, an enzyme breaking down adenosine, reverses the inhibitory action of dipyridamole. Two different adenosine receptor antagonists, 5’-deoxy-5’-methylthioadenosine and theophylline, also partially neutralize the activity of dipyridamole in blood. Enprofylline, a phosphodiesterase inhibitor with almost no adenosine receptor antagonistic properties, potentiates the inhibition of platelet aggregation by dipyridamole. An inhibitory effect similar to that of dipyridamole can be obtained combining a pure adenosine uptake inhibitor (RE 102 BS) with a pure phosphodiesterase inhibitor (MX-MB 82 or enprofylline). Mixing the blood during preincubation with dipyridamole increases the degree of inhibition. Lowering the haematocrit slightly reduces the effectiveness.Although we did not carry out direct measurements of adenosine levels, the results of our pharmacological studies clearly show that dipyridamole inhibits platelet aggregation in whole blood by blocking the reuptake of adenosine formed from precursors released by red blood cells following microtrauma. Its slight phosphodiesterase inhibitory action potentiates the effects of adenosine on platelets.

scholarly journals Identification and Predictions Regarding the Biosynthesis Pathway of Polyene Macrolides Produced by Streptomyces roseoflavus Men-myco-93-63

2021 ◽  
Vol 87 (10) ◽  
Author(s):  
Xing Han ◽  
Jiao Wang ◽  
Lianna Liu ◽  
Fengying Shen ◽  
Qingfang Meng ◽  
...  
Keyword(s):  
Fermentation Broth ◽  
Pathogenic Fungi ◽  
Biosynthetic Gene Cluster ◽  
Inhibitory Effect ◽  
Plant Diseases ◽  
Active Metabolites ◽  
Content Type ◽  
Polyene Macrolides ◽  
Alternative Agent

ABSTRACT A group of polyene macrolides mainly composed of two constituents was isolated from the fermentation broth of Streptomyces roseoflavus Men-myco-93-63, which was isolated from soil where potato scabs were repressed naturally. One of these macrolides was roflamycoin, which was first reported in 1968, and the other was a novel compound named Men-myco-A, which had one methylene unit more than roflamycoin. Together, they were designated RM. This group of antibiotics exhibited broad-spectrum antifungal activities in vitro against 17 plant-pathogenic fungi, with 50% effective concentrations (EC50) of 2.05 to 7.09 μg/ml and 90% effective concentrations (EC90) of 4.32 to 54.45 μg/ml, which indicates their potential use in plant disease control. Furthermore, their biosynthetic gene cluster was identified, and the associated biosynthetic assembly line was proposed based on a module and domain analysis of polyketide synthases (PKSs), supported by findings from gene inactivation experiments. IMPORTANCE Streptomyces roseoflavus Men-myco-93-63 is a biocontrol strain that has been studied in our laboratory for many years and exhibits a good inhibitory effect in many crop diseases. Therefore, the identification of antimicrobial metabolites is necessary and our main objective. In this work, chemical, bioinformatic, and molecular biological methods were combined to identify the structures and biosynthesis of the active metabolites. This work provides a new alternative agent for the biological control of plant diseases and is helpful for improving both the properties and yield of the antibiotics via genetic engineering.

scholarly journals Psoromic Acid, a Lichen-Derived Molecule, Inhibits the Replication of HSV-1 and HSV-2, and Inactivates HSV-1 DNA Polymerase: Shedding Light on Antiherpetic Properties

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2912 ◽  
Author(s):  
Sherif T. S. Hassan ◽  
Miroslava Šudomová ◽  
Kateřina Berchová-Bímová ◽  
Karel Šmejkal ◽  
Javier Echeverría
Keyword(s):  
Dna Polymerase ◽  
Active Sites ◽  
Inhibitory Action ◽  
Inhibitory Concentration ◽  
Competitive Inhibition ◽  
Inhibitory Effect ◽  
Standard Drug ◽  
Key Enzyme ◽  
Hsv 1

Psoromic acid (PA), a bioactive lichen-derived compound, was investigated for its inhibitory properties against herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), along with the inhibitory effect on HSV-1 DNA polymerase, which is a key enzyme that plays an essential role in HSV-1 replication cycle. PA was found to notably inhibit HSV-1 replication (50% inhibitory concentration (IC50): 1.9 μM; selectivity index (SI): 163.2) compared with the standard drug acyclovir (ACV) (IC50: 2.6 μM; SI: 119.2). The combination of PA with ACV has led to potent inhibitory activity against HSV-1 replication (IC50: 1.1 µM; SI: 281.8) compared with that of ACV. Moreover, PA displayed equivalent inhibitory action against HSV-2 replication (50% effective concentration (EC50): 2.7 μM; SI: 114.8) compared with that of ACV (EC50: 2.8 μM; SI: 110.7). The inhibition potency of PA in combination with ACV against HSV-2 replication was also detected (EC50: 1.8 µM; SI: 172.2). Further, PA was observed to effectively inhibit HSV-1 DNA polymerase (as a non-nucleoside inhibitor) with respect to dTTP incorporation in a competitive inhibition mode (half maximal inhibitory concentration (IC50): 0.7 μM; inhibition constant (Ki): 0.3 μM) compared with reference drugs aphidicolin (IC50: 0.8 μM; Ki: 0.4 μM) and ACV triphosphate (ACV-TP) (IC50: 0.9 μM; Ki: 0.5 μM). It is noteworthy that the mechanism by which PA-induced anti-HSV-1 activity was related to its inhibitory action against HSV-1 DNA polymerase. Furthermore, the outcomes of in vitro experiments were authenticated using molecular docking analyses, as the molecular interactions of PA with the active sites of HSV-1 DNA polymerase and HSV-2 protease (an essential enzyme required for HSV-2 replication) were revealed. Since this is a first report on the above-mentioned properties, we can conclude that PA might be a future drug for the treatment of HSV infections as well as a promising lead molecule for further anti-HSV drug design.

Effect of adrenalectomy on the regulation of the secretion of gonadotrophins and prolactin in the lactating rat

1983 ◽  
Vol 98 (2) ◽  
pp. 227-232 ◽  
Author(s):  
P. van der Schoot ◽  
W. J. de Greef
Keyword(s):  
Plasma Levels ◽  
Inhibitory Action ◽  
Adrenal Glands ◽  
Marked Effect ◽  
Plasma Concentrations ◽  
Inhibitory Effect ◽  
Blood Levels ◽  
Adrenal Hormones ◽  
Adrenocortical Hormones ◽  
Adrenalectomized Rats

The suckling stimulus exerts an inhibitory action on the release of gonadotrophins during lactation. The possible involvement of the adrenal glands in this process was examined by studying the plasma levels of gonadotrophins in lactating rats ovariectomized on the day after parturition. It appeared that the suppression, throughout suckling, of the rise in levels of gonadotrophins in blood after ovariectomy occurred to the same extent in adrenalectomized and in sham-operated animals. It thus seems unlikely that adrenocortical hormones, albeit secreted in larger quantities during lactation, exert an inhibitory effect on the release of gonadotrophins. Adrenalectomy had a marked effect on the plasma concentrations of prolactin during the second half of lactation. Whereas plasma concentrations of prolactin in the first half of lactation were similar in adrenalectomized and sham-operated rats, the concentrations in adrenalectomized rats did not undergo the reduction found in sham-operated rats. Adrenal hormones may thus be involved in the reduction of blood levels of prolactin observed in rats and in other mammals as lactation progresses.

scholarly journals Effect of oil cake extract and organic manure on wilt of chickpea (Cicer areitinum L.) caused by Fusarium oxysporum f. sp. ciceri in vitro

2021 ◽  
Vol 17 (2) ◽  
pp. 146-148
Author(s):  
Ashish Shrivastava
Keyword(s):  
Growth Inhibition ◽  
Fusarium Oxysporum ◽  
Maximum Growth ◽  
Inhibitory Effect ◽  
Organic Manure ◽  
Percent Reduction ◽  
Organic Manures ◽  
Neem Cake ◽  
Oil Cakes

Studies were conducted to test the effect of oil cakes and organic manures on the growth of wilt pathogen under in vitro conditions. The extract of different oil cakes and organic manures were tested against F. oxysporum f. sp. ciceri by poisoned food techniques in vitro. Least growth of pathogen was recorded in extracts of Neem cake showing excellent inhibitory effect of 70.87 percent reduction over control. Next best in order of mustard cake (65.36 %), linseed (62.99%), groundnut (53.36%) and least by other. Among the organic manures tested, vermi compost and FYM showed maximum growth inhibition of 35.95 and 30.62 percent over control, respectively.

scholarly journals Antifungal activity of saponins originated from Medicago hybrida against some ornamental plant pathogens

2012 ◽  
Vol 59 (2) ◽  
pp. 51-58 ◽  
Author(s):  
Alicja Saniewska ◽  
Anna Jarecka ◽  
Zbigniew Biały ◽  
Marian Jurzysta
Keyword(s):  
Antifungal Activity ◽  
Fusarium Oxysporum ◽  
Botrytis Cinerea ◽  
Plant Pathogens ◽  
Pathogenic Fungi ◽  
Ornamental Plant ◽  
Mycelium Growth ◽  
Medicagenic Acid ◽  
Fungitoxic Effect

Antifungal activity of total saponins originated from roots of <i>Medicago hybrida</i> (Pourret) Trautv. were evaluated <i>in vitro</i> against six pathogenic fungi and eight individual major saponin glycosides were tested against one of the most susceptible fungi. The total saponins showed fungitoxic effect at all investigated concentrations (0.01%, 0.05% and 0.1%) but their potency was different for individual fungi. The highest saponin concentration (0.1%) was the most effective and the inhibition of <i>Fusarium oxysporum</i> f. sp. <i>callistephi</i>, <i>Botrytis cinerea</i>, <i>Botrytis tulipae</i>, <i>Phoma narcissi</i>, <i>Fusarium oxysporum</i> f. sp. <i>narcissi</i> was 84.4%, 69.9%, 68.6%, 57.2%, 55.0%, respectively. While <i>Fusarium oxysporum</i> Schlecht., a pathogen of <i>Muscari armeniacum</i>, was inhibited by 9.5% only. Eight major saponin glycosides isolated from the total saponins of <i>M. hybrida</i> roots were tested against the mycelium growth of <i>Botrytis tulipae</i>. The mycelium growth of the pathogen was greatly inhibited by hederagenin 3-O-<i>β</i>-D-glucopyranoside and medicagenic acid 3-O-<i>β</i>-D-glucopyranoside. Medicagenic acid 3-O-<i>β</i>-D-glucuronopyranosyl-28-O-<i>β</i>-D-glucopyranoside and oleanolic acid 3-O-[<i>β</i>-D-glucuronopyranosyl(1→2)-<i>α</i>-L-galactopyranosyl]-28-O-<i>β</i>-D-glucopyranoside showed low fungitoxic activity. Medicagenic acid 3-O-a-D-glucopyranosyl- 28-O-β-D-glucopyranoside, hederagenin 3-O-[α-L- hamnopyranosyl(1→2)-β-D-glucopyranosyl(1→2)-β-D-glucopyranosyl]- 28-O-α-D-glucopyranoside and hederagenin 3-O-<i>β</i>-D-glucuronopyranosyl-28-O-<i>β</i>-D- lucopyranoside did not limit or only slightly inhibited growth of the tested pathogen. While 2<i>β</i>, 3<i>β</i>-dihydroxyolean-12 ene-23-al-28-oic acid 3-O-<i>β</i>-D-glucuronopyranosyl-28-O-<i>β</i>-D-glucopyranoside slightly stimulated mycelium growth of <i>B. tulipae</i>.

scholarly journals The biological activity of subspecies Trichoderma harzianum against Fusarium oxysporum, the causative agent of fusarium wilt cucumber in vitro

2020 ◽  
Vol 21 ◽  
pp. 00021
Author(s):  
Ninel Pavlovskaya ◽  
Irina Gneusheva ◽  
Irina Solokhina ◽  
Natalya Ageeva
Keyword(s):  
Biological Activity ◽  
Fusarium Oxysporum ◽  
Trichoderma Harzianum ◽  
Pathogenic Fungi ◽  
Chitinase Activity ◽  
Lytic Enzymes ◽  
Growth Promoting ◽  
Phytopathogenic Microorganisms ◽  
Trichoderma Lixii

The study of the effect of the strains of the fungus Trichoderma: Trichoderma atrobrunneum VKPM F-1434, Trichoderma harzianum 5/14, Trichoderma Lixii T4/14 on the number of micromycetes populations of the pathogenic fungi Fusarium oxysporum isolate B/14, Fusarium oxysporum isolate MOS509, Fysarium oxysporum isolate IMI58289 in vitro. It was found that the Trichoderma atrobrunneum fungus strain VKPM F-1434 showed the highest degree of inhibition on 10 days of cultivation with phytopathogenic microorganisms, which was 100 %. The study revealed that all Trichoderma species are capable of producing lytic enzymes. Trichoderma atrobrunneum strain VKPM F-1434 exhibits strong lipase and chitinase activity and average proteinase activity. In addition, Trichoderma atrobrunneum strain VKPM F-1434 has a growth-promoting ability, which was reflected in the germination of seeds of cucumber “German F1”. The maximum values of indicators of germination energy were noted – 98.4 % and germination – 100 %.

Novel Strobilurin Derivatives Containing Carboxylate Unit as Potential Antifungal Agents

2020 ◽  
Vol 17 (3) ◽  
pp. 300-311
Author(s):  
Longzhu Bao ◽  
Shuangshuang Wang ◽  
Di Song ◽  
Jingjing Wang ◽  
Xiali Yue ◽  
...  
Keyword(s):  
Fungicidal Activity ◽  
Pathogenic Fungi ◽  
Inhibitory Effect ◽  
Phytopathogenic Fungi ◽  
Side Chain ◽  
Test Results ◽  
Strobilurin Fungicide ◽  
Low Toxicity ◽  
Control Failures

Background: Due to the extensive use of a single fungicide to control crop diseases, the increase of resistant individuals leads to control failures. The search for molecules with fungicidal activity is still ongoing. Strobilurin is one of the most popularly used fungicides in the agrochemical field. A large number of strobilurin derivatives with both high activity and low toxicity have been developed. Methods: In the present study, a series of novel ortho-substituted benzyl carboxylates were efficiently synthesized by the reaction of (E)-methyl 2-(2-(bromom-ethyl)phenyl)-2-methox-yiminoaceta with various carboxylic acids. Their structures were confirmed and characterized by 1H NMR, 13C NMR, and ESI-MS analysis. Their fungicidal activities against common phytopathogenic fungi from six major cash crops were screened based on the pesticides guidelines for the laboratory bioactivity tests. Results: The primary fungicidal activity test results indicate that all compounds showed a certain inhibitory effect on the growth of 13 plants pathogenic fungi at a concentration of 100 ppm, and Compd. 3 has the most obvious inhibitory effect on all fungi. Further fungicidal activity studies indicate that some of these novel strobilurin derivatives containing carboxylate unit exhibited potential in vitro fungicidal activities at the dosage of 6.25 mg/L-1. Conclusion: A series of the ortho-substituted benzyl carboxylates derivatives containing β- methoxyacrylate moiety were designed and synthesized by modifying the side chain of traditional strobilurin fungicide. Compd. 3, Compd. 2 and Compd. 16 were identified as the most promising candidates for further study.

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