Postinfectional inhibitors from plants. XV. Antifungal activity of the phytoalexin orchinol and related phenanthrenes and stilbenes

1975 ◽  
Vol 53 (10) ◽  
pp. 964-971 ◽  
Author(s):  
E. W. B. Ward ◽  
C. H. Unwin ◽  
A. Stoessl
Keyword(s):  
Antifungal Activity ◽  
Effective Dose ◽  
Spore Germination ◽  
Plant Tissue ◽  
Striking Feature ◽  
Monilinia Fructicola ◽  
Higher Plant ◽  
Similar Activity ◽  
Germ Tubes ◽  
Laboratory Synthesis

Orchinol, loroglossol, and several related phenanthrenes and stilbenes obtained by laboratory synthesis were tested for antifungal activity, primarily in spore germination assays against Monilinia fructicola and Phytophthora infestons. The most active stilbene tested was 3,5-dimethoxy-3′-hydroxystilbene (mean effective dose (ED50) 5 × 10−5 M), at least comparable with the reported activity of the stilbene phytoalexin, pinosylvin. All the phenanthrenes and dihydrophenanthrenes tested were active, although assays were complicated by solubility problems. ED50 for orchinol was (5 × 10−5 M) and loroglossol had similar activity against P. infestons. Several phenanthrenes had higher activity, notably dehydroorchinol (ED50 vs. P. infestons 5 × 10−6 M), and warrant further study. A striking feature of the response of the test fungi to the phenanthrenes and dihydrophenanthrenes was the production of distorted and ruptured germ tubes, which may indicate a direct interference with growth processes at the tip. No evidence was obtained for translocation of orchinol in higher plant tissue.

Postinfectional inhibitors from plants. XXIII. Sesquiterpenoid phytoalexins from fruit capsules of Datura stramonium

1976 ◽  
Vol 54 (1-2) ◽  
pp. 25-29 ◽  
Author(s):  
E. W. B. Ward ◽  
C. H. Unwin ◽  
G. L. Rock ◽  
A. Stoessl
Keyword(s):  
Antifungal Activity ◽  
Detailed Analysis ◽  
Spore Germination ◽  
Pathogenic Fungi ◽  
Datura Stramonium ◽  
Monilinia Fructicola ◽  
Column Chromatographic

Datura stramonium fruit capsules inoculated with Monilinia fructicola or several other non-pathogenic fungi produced diffusates inhibitory to M. fructicola in spore germination assays. Detailed analysis of diffusates that are induced by M. fructicola indicated that they were complex and that antifungal activity was widely distributed through a number of column chromatographic fractions. Four compounds were isolated. These were sesquiterpenes, three of which, lubimin, hydroxylubimin, and capsidiol, have been described from other Solanaceae. The fourth, 2,3-dihydroxygermacrene, is a new compound with moderate antifungal activity but which is of especial interest as a possible precursor of several phytoalexins in the Solanaceae.

Characteristics and Function of the Chitin Binding Protein from Xenorhabdus nematophila

2019 ◽  
Vol 26 (6) ◽  
pp. 414-422
Author(s):  
Jia Liu ◽  
Ping Song ◽  
Jie Zhang ◽  
Ziyan Nangong ◽  
Xiaobei Liu ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Growth Inhibition ◽  
Insecticidal Activity ◽  
Spore Germination ◽  
Binding Protein ◽  
Colloidal Chitin ◽  
Inhibition Rate ◽  
Xenorhabdus Nematophila ◽  
Chitin Binding Protein ◽  
And Function

Background: Genome sequence analysis (GenBank access No.: FN667742.1) shows that Xenorhabdus nematophila ATCC19061 contains one gene (Xn-cbp) encoding chitin binding protein (Xn-CBP). Objective: The present work aims to clarify the characteristics and function of Xn-CBP from X. nematophila HB310. Methods: In this study, the Xn-cbp gene was cloned and expressed in Escherichia coli BL21 (DE3). Substrate binding assays were performed to explain the ability of Xn-CBP combined with the polysaccharide. The insecticidal toxicity of Xn-CBP against the second-instar larvae of Helicoverpa armigera was determined by feeding method. Besides, the antifungal activity of Xn-CBP against Coniothyrium diplodiella, Verticillium dahlia, and Fusarium oxysporum was tested by spore germination assay and hyphal extension assay. Results: Xn-CBP encoded 199 amino acids with a calculated mass of 28 kDa, which contained a signal peptide and a chitin binding domain. The Bmax and Kd values of Xn-CBP to colloidal chitin were 2.46 and 4.08, respectively. Xn-CBP had insecticidal activity against the H. armigera with a growth inhibition rate of 84.08%. Xn-CBP had the highest spore germination inhibitory effect on C. diplodiella with the inhibition rate of 83.11%. The hyphal growth inhibition rate of Xn-CBP to F. oxysporum, 41.52%, was higher than the other two fungi. Conclusion: The Xn-CBP had the highest binding ability to colloidal chitin and it showed insecticidal activity and antifungal activity. The present study laid a foundation for further exploitation and utilization of X. nematophila.

Homogenate Extraction of Dihydroartemisinin from Artemisia Hedinii and Its Antifungal Activity

2021 ◽  
Author(s):  
Cong You ◽  
Jun Yu ◽  
Guangjiong Qin ◽  
JinPeng Yang ◽  
Chunlei Yang ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Crude Extract ◽  
Spore Germination ◽  
Alternaria Alternata ◽  
Low Cost ◽  
Pathogenic Fungi ◽  
Extraction Yield ◽  
Optimal Conditions ◽  
Extraction Technology ◽  
Homogenate Extraction

Abstract Background Artemisia hedinii is a well-known traditional Chinese medicine. It can be used to extract dihydroartemisinin (DHA). Objective The purpose of this study was to explore the optimal conditions for the homogenate extraction of DHA from A. hedinii and the antifungal activity of DHA. Methods In this study, single factor experiments and response surface method were used to determine the optimal extraction conditions of crude extract and DHA, the method of spore germination was used to study the antifungal activity of DHA to Alternaria alternata. Result The optimal conditions were found as fellow: ratio of liquid to material 22 mL/g; Extraction time 60 s; soaking time 34 min. Under these conditions, extraction yield of DHA was (1.76 ± 0.04%). When the concentration of crude extract were 0.5 and 8 mg/mL, the spore germination inhibition rates of Alternaria alternata were (17.00 ± 2.05%) and (92.56 ± 2.01%), which were 3.34 and 1.15 times that of DHA standard, respectively. Conclusion Homogenate extraction technology is a fast and efficient method to extract DHA from A. hedinii. The crude extract has significant antifungal activity against A. alternata with low cost, which provides a possibility for the use of DHA in the prevention and treatment of plant pathogenic fungi. Highlights The optimum conditions of the extraction of DHA from A. hedinii by homogenate extraction were obtained. DHA has antifungal activity against A. alternata. Compared with pure DHA, the crude extract has stronger antifungal activity against A. alternata.

scholarly journals Hevein-Like Antimicrobial Peptides Wamps: Structure–Function Relationship in Antifungal Activity and Sensitization of Plant Pathogenic Fungi to Tebuconazole by WAMP-2-Derived Peptides

2020 ◽  
Vol 21 (21) ◽  
pp. 7912 ◽  
Author(s):  
Tatyana Odintsova ◽  
Larisa Shcherbakova ◽  
Marina Slezina ◽  
Tatyana Pasechnik ◽  
Bakhyt Kartabaeva ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Antimicrobial Peptides ◽  
Structure Function ◽  
Spore Germination ◽  
Pathogenic Fungi ◽  
Plant Pathogenic Fungi ◽  
Fungal Cell ◽  
Structure Function Relationship ◽  
Function Relationship

Hevein-like antimicrobial peptides (AMPs) comprise a family of plant AMPs with antifungal activity, which harbor a chitin-binding site involved in interactions with chitin of fungal cell walls. However, the mode of action of hevein-like AMPs remains poorly understood. This work reports the structure–function relationship in WAMPs—hevein-like AMPs found in wheat (Triticum kiharae Dorof. et Migush.) and later in other Poaceae species. The effect of WAMP homologues differing at position 34 and the antifungal activity of peptide fragments derived from the central, N- and C-terminal regions of one of the WAMPs, namely WAMP-2, on spore germination of different plant pathogenic fungi were studied. Additionally, the ability of WAMP-2-derived peptides to potentiate the fungicidal effect of tebuconazole, one of the triazole fungicides, towards five cereal-damaging fungi was explored in vitro by co-application of WAMP-2 fragments with Folicur® EC 250 (25% tebuconazole). The antifungal activity of WAMP homologues and WAMP-2-derived peptides varied depending on the fungus, suggesting multiple modes of action for WAMPs against diverse pathogens. Folicur® combined with the WAMP-2 fragments inhibited the spore germination at a much greater level than the fungicide alone, and the type of interactions was either synergistic or additive, depending on the target fungus and concentration combinations of the compounds. The combinations, which resulted in synergism and drastically enhanced the sensitivity to tebuconazole, were revealed for all five fungi by a checkerboard assay. The ability to synergistically interact with a fungicide and exacerbate the sensitivity of plant pathogenic fungi to a commercial antifungal agent is a novel and previously uninvestigated property of hevein-like AMPs.

The antifungal factors in barley. V. Antifungal activity of the hordatines

1970 ◽  
Vol 48 (3) ◽  
pp. 465-470 ◽  
Author(s):  
A. Stoessl ◽  
C. H. Unwin
Keyword(s):  
Antifungal Activity ◽  
Spore Germination ◽  
Divalent Cations ◽  
Natural Defense ◽  
Antifungal Substances

The hordatines, antifungal substances previously isolated from barley seedlings grown in the dark, are also produced under conditions which approximate those in the field. The compounds, and some of their derivatives, inhibit the spore germination of a number of fungi in concentrations as low as 10−5 M. Inhibition is reversed by the addition of some divalent cations; this observation supports the identity of the hordatines with the natural defense agents of barley which have been demonstrated in earlier work.

Sensitivity of Ulocladium atrum, Coniothyrium minitans, and Sclerotinia sclerotiorum to benomyl and vinclozolin

2002 ◽  
Vol 80 (8) ◽  
pp. 892-898 ◽  
Author(s):  
G Q Li ◽  
H C Huang ◽  
S N Acharya
Keyword(s):  
Growth Inhibition ◽  
Sclerotinia Sclerotiorum ◽  
Spore Germination ◽  
Mycelial Growth ◽  
Germination Rate ◽  
Effective Concentration ◽  
Coniothyrium Minitans ◽  
Inhibition Concentration ◽  
Maximum Inhibition ◽  
Germ Tubes

Assays on mycelial growth and spore germination were carried out to determine the sensitivity of the biocontrol agents Ulocladium atrum and Coniothyrium minitans and the plant pathogen Sclerotinia sclerotiorum to benomyl and vinclozolin. Ulocladium atrum was more tolerant to these fungicides than C. minitans and S. sclerotiorum. The 50% effective concentration (EC50) of U. atrum based on the mycelial growth inhibition was 1467.3 µg active ingredient (a.i.)/mL for benomyl and 12.6 µg a.i./mL for vinclozolin, and the maximum inhibition concentration was higher than 4000 µg a.i./mL for both fungicides. For C. minitans and S. sclerotiorum, however, the EC50 based on mycelial growth inhibition was lower than 1 µg a.i./mL. After incubation for 24 h at 20°C, the germination rate of U. atrum conidia was 90–99% on potato dextrose agar (PDA) amended with benomyl at 100–500 µg a.i./mL or vinclozolin at 10–500 µg a.i./mL. At these concentrations, germ tubes of U. atrum developed into long, branched hyphae in benomyl treatments, but they remained short and clustered in vinclozolin treatments. Pycnidiospores of C. minitans and ascospores of S. sclerotiorum germinated on PDA amended with benomyl at 100–500 µg a.i./mL, but the germ tubes did not grow further. Spore germination of C. minitans and S. sclerotiorum was less than 3.2% on PDA amended with vinclozolin at 10–500 µg a.i./mL after 24 h. This is the first report on the sensitivity of U. atrum and C. minitans to benomyl and vinclozolin. The results suggest that it is possible to control S. sclerotiorum using a combination of U. atrum and benomyl or vinclozolin.Key words: fungicides, mycelial growth, spore germination, integrated pest management.

scholarly journals Effect of Temperature on the Discharge and Germination of Ascospores by Apothecia of Monilinia fructicola

Plant Disease ◽  
1998 ◽  
Vol 82 (2) ◽  
pp. 195-202 ◽  
Author(s):  
Chuanxue Hong ◽  
Themis J. Michailides
Keyword(s):  
Management Strategies ◽  
Brown Rot ◽  
Effect Of Temperature ◽  
Monilinia Fructicola ◽  
Stone Fruits ◽  
Warning Systems ◽  
Fresno County ◽  
Ascospore Germination ◽  
Daily Discharge ◽  
Germ Tubes

Naturally growing apothecia of Monilinia fructicola were collected from two commercial plum orchards near Reedley and Sanger, both in Fresno County, California. Ascospore discharges from 90 (1996) and 86 (1997) apothecia were monitored individually using spore traps at four constant temperatures. The period of discharge decreased as temperature increased from 10 to 25°C. However, daily discharge increased as temperature increased from 10 to 15°C and remained high at 20 and 25°C. The greatest discharge occurred with apothecia at 15°C, followed by those incubated at 20, 10, and 25°C. The germination of ascospores of M. fructicola and the length of germ tubes increased as temperature increased from 7 to 15°C; however, increasing temperatures above 15°C did not increase either ascospore germination or length of germ tubes. This information may help in the development of warning systems and management strategies for brown rot blossom blight of stone fruits.

Hydrolysis of protein in vacuoles isolated from higher plant tissue

Nature ◽  
1979 ◽  
Vol 277 (5695) ◽  
pp. 412-413 ◽  
Author(s):  
MIKIO NISHIMURA ◽  
HARRY BEEVERS
Keyword(s):  
Plant Tissue ◽  
Higher Plant ◽  
Hydrolysis Of

scholarly journals Inhibition of Aspergillus niger DMF 0801 by monoacylglycerols prepared from coconut oil

2011 ◽  
Vol 20 (No. 2) ◽  
pp. 48-52 ◽  
Author(s):  
Z. Řiháková ◽  
V. Filip ◽  
M. PlockovÁ ◽  
J. Šmidrkal ◽  
R. Červenková
Keyword(s):  
Antifungal Activity ◽  
Aspergillus Niger ◽  
Growth Inhibition ◽  
Lauric Acid ◽  
Spore Germination ◽  
Radial Growth ◽  
Coconut Oil ◽  
Germination Inhibition ◽  
Inhibition Effect ◽  
Antifungal Properties

The objectives of the present study were to test the antifungal properties (inhibition of radial growth, inhibition of the mould spore germination) of lauroylglycerol and mixtures of monoacylglycerols synthesised from coconut oil (MIX-I and MIX-II) against Aspergillus niger DMF 0801. The content of monoacylglycerols in lauroylglycerol, MIX-I and MIX-II was 99.9% (w/w), 97.7% (w/w) and 75,1% (w/w), respectively. The content of 1-lauroylglycerol in MIX-I and MIX-II was calculated from the content of lauric acid and content of monoacylglycerols. The inhibition of the radial growth of Aspergillus niger DMF 0801 by lauroylglycerol was stronger than that caused by MIX-I and MIX-II. The inhibition effect of spore germination caused by lauroylglycerol and MIX-I was nearly the same. The inhibition of spore germination increased with increasing content of monoacylglycerol and also with increasing 1-lauroylglycerol content in monoacylglycerols. The level of spore germination inhibition was related to the purity of tested substances. The results of this study indicate that monoacylglycerols made from coconut oil have antifungal activity.  

scholarly journals Differences Between Ascospores and Conidia of Didymella rabiei in Spore Germination and Infection of Chickpea

2007 ◽  
Vol 97 (12) ◽  
pp. 1600-1607 ◽  
Author(s):  
Antonio Trapero-Casas ◽  
Walter J. Kaiser
Keyword(s):  
Disease Severity ◽  
Spore Germination ◽  
Opposite Effect ◽  
Disease Development ◽  
Optimum Temperature ◽  
Water Potentials ◽  
Wetness Period ◽  
Moisture Conditions ◽  
Germ Tubes ◽  
Plant Surfaces

Studies were performed to compare the germination and infection of ascospores and conidia of Didymella rabiei under different temperature and moisture conditions. Germination of ascospores and conidia on cover glasses coated with water agar began after 2 h, with maximum germination (>95%) occurring in 6 h at 20°C. No germination occurred at 0 and 35°C. Ascospores germinated more rapidly than conidia at all temperatures. Germination declined rapidly as the water potential varied from 0 to –4 MPa, although some germination occurred at –6 MPa at 20 and 25°C. Ascospores germinated over a wider range of water potentials than conidia and their germ tubes were longer than those of conidia at most water potentials and temperatures. The optimum temperature for infection and disease development by both ascospores and conidia was around 20°C. Disease severity was higher when ascospores were discharged directly onto plant surfaces from naturally infested chickpea debris compared with aqueous suspensions of ascospores and conidia sprayed onto plants Disease severity increased as the length of the wetness period increased. When dry periods of 6 to 48 h occurred immediately after inoculation, disease severity decreased, except for the shorter periods which had the opposite effect. Disease severity was higher with ascospore inoculum when no dry periods occurred after inoculation.

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