The inhibitory effect of volatile organic compounds produced by Bacillus subtilis CL2 on pathogenic fungi of wolfberry

The fungicidal effects of secondary metabolites produced by a strain of Penicillium expansum (R82) in culture filtrate and in a double petri dish assay were tested against one isolate each of Botrytis cinerea, Colletotrichum acutatum, and Monilinia laxa and six isolates of P. expansum, revealing inhibitory activity against every pathogen tested. The characterization of volatile organic compounds released by the R82 strain was performed by solid-phase microextraction–gas chromatographic techniques, and several compounds were detected, one of them identified as phenethyl alcohol (PEA). Synthetic PEA, tested in vitro on fungal pathogens, showed strong inhibition at a concentration of 1,230 μg/ml of airspace, and mycelium appeared more sensitive than conidia; nevertheless, at the concentration naturally emitted by the fungus (0.726 ± 0.16 μg/ml), commercial PEA did not show any antifungal activity. Therefore, a combined effect between different volatile organic compounds produced collectively by R82 can be hypothesized. This aspect suggests further investigation into the possibility of exploiting R82 as a nonchemical alternative in the control of some plant pathogenic fungi.

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Identification and analysis of odor-active compounds from Choerospondias axillaris (Roxb.) Burtt et Hill with different moisture content levels and lacquer treatments

Scientific Reports ◽

10.1038/s41598-020-71698-0 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Qifan Wang ◽

Jun Shen ◽

Bin Zeng ◽

Huiyu Wang

Keyword(s):

Volatile Organic Compounds ◽

Moisture Content ◽

Organic Compounds ◽

Inhibitory Effect ◽

Waterborne Coating ◽

Active Compounds ◽

Antiseptic Solution ◽

Volatile Organic ◽

Gas Chromatography Mass Spectroscopy ◽

Total Volatile Organic Compounds

Abstract The problem of indoor odors can greatly affect a room’s occupants. To identify odorants and comprehensively evaluate emissions from wooden materials, emissions and odors from Choerospondias axillaris (Roxb.) Burtt et Hill with different moisture content percentages and lacquer treatments were investigated in this study. Thermal desorption–gas chromatography–mass spectroscopy/olfactometry was used to analyze the release characteristics. In total, 11 key odor-active compounds were identified as moisture content gradually decreased, concentrating between 15 and 33 min. Total volatile organic compounds, total very volatile organic compounds, and total odor intensity decreased as moisture content decreased. In addition, 35 odor-active compounds, including aromatics, alkenes, aldehydes, esters, and alcohols, were identified in the odor control list. Polyurethane (PU), ultraviolet (UV), and waterborne coatings had a good inhibitory effect on eight odor characteristics, but some scents arose after lacquer treatment. For equilibrium moisture content, the major characteristics of Choerospondias axillaris were fragrant (9.4) and mint-like (3.0) compared with the fragrant (8.2), fruity (7.8), and pleasant (5.8) characteristics of PU coating; the flowery (5.9), fragrant (5.0), glue-like (4.3), and pineapple-like (4.3) characteristics of UV coating; and the antiseptic solution (3.6), fragrant (2.9), cigarette-like (2.8), and fruity (2.5) characteristics of waterborne coating. Based on multicomponent evaluation, a Choerospondias axillaris board with waterborne coating was suggested for use indoors.

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Defensive functions of volatile organic compounds and essential oils from northern white-cedar in China

BMC Plant Biology ◽

10.1186/s12870-020-02716-6 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Liping Bai ◽

Wenjia Wang ◽

Juan Hua ◽

Zhifu Guo ◽

Shihong Luo

Keyword(s):

Volatile Organic Compounds ◽

Essential Oils ◽

Organic Compounds ◽

Pathogenic Fungi ◽

Early Spring ◽

Curvularia Lunata ◽

Plant Communication ◽

Volatile Organic ◽

Cultivated Plant ◽

High Concentrations

Abstract Background Plants are known to emit diverse volatile organic compounds (VOCs), which may function as signaling substances in plant communication with other organisms. Thuja occidentalis, which is widely cultivated throughout China, releases aromatic VOCs into the air in winter and early spring. The relationship of this cultivated plant with its neighboring plants is necessary for the conservation of biodiversity. Results (−)-α-thujone (60.34 ± 5.58%) was found to be the major component in VOCs from the Shenyang population. The essential oils (EOs) from the Kunming and Shenyang populations included the major components (−)-α-thujone, fenchone, (+)-β-thujone, and (+)-hibaene, identified using GC-MS analyses. (−)-α-thujone and (+)-hibaene were purified and identified by NMR identification. EOs and (−)-α-thujone exhibited valuable phytotoxic activities against seed germination and seedling growth of the plants Taraxacum mongolicum and Arabidopsis thaliana. Moreover, the EOs displayed potent inhibitory activity against pathogenic fungi of maize, including Fusarium graminearum, Curvularia lunata, and Bipolaris maydis, as well as one human fungal pathogen, Candida albicans. Quantitative analyses revealed high concentrations of (−)-α-thujone in the leaves of T. occidentalis individuals from both the Shenyang and Kunming populations. However, (−)-α-thujone (0.18 ± 0.17 μg/g) was only detected in the rhizosphere soil to a distance of 0.5 m from the plant. Conclusions Taken together, our results suggest that the phytotoxic effects and antifungal activities of the EOs and (−)-α-thujone in T. occidentalis certainly increased the adaptability of this plant to the environment. Nevertheless, low concentrations of released (−)-α-thujone indicated that reasonable distance of T. occidentalis with other plant species will impair the effects of allelochemical of T. occidentalis.

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Antifungal Effect of Volatile Organic Compounds from Bacillus velezensis CT32 against Verticillium dahliae and Fusarium oxysporum

Processes ◽

10.3390/pr8121674 ◽

2020 ◽

Vol 8 (12) ◽

pp. 1674

Author(s):

Xinxin Li ◽

Xiuhong Wang ◽

Xiangyuan Shi ◽

Baoping Wang ◽

Meiping Li ◽

...

Keyword(s):

Antifungal Activity ◽

Volatile Organic Compounds ◽

Fusarium Oxysporum ◽

Organic Compounds ◽

Verticillium Dahliae ◽

Inhibitory Effect ◽

Rrna Gene ◽

Vascular Wilt ◽

Bacillus Velezensis ◽

Volatile Organic

The present study focuses on the inhibitory effect of volatile metabolites released by Bacillus velezensis CT32 on Verticillium dahliae and Fusarium oxysporum, the causal agents of strawberry vascular wilt. The CT32 strain was isolated from maize straw compost tea and identified as B. velezensis based on 16S rRNA gene sequence analysis. Bioassays conducted in sealed plates revealed that the volatile organic compounds (VOCs) produced by the strain CT32 possessed broad-spectrum antifungal activity against eight phytopathogenic fungi. The volatile profile of strain CT32 was obtained by headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). A total of 30 volatile compounds were identified, six of which have not previously been detected in bacteria or fungi: (Z)-5-undecene, decyl formate, 2,4-dimethyl-6-tert-butylphenol, dodecanenitrile, 2-methylpentadecane and 2,2’,5,5’-tetramethyl-1,1’-biphenyl. Pure compounds were tested in vitro for their inhibitory effect on the mycelial growth of V. dahliae and F. oxysporum. Decanal, benzothiazole, 3-undecanone, 2-undecanone, 2-undecanol, undecanal and 2,4-dimethyl-6-tert-butylphenol showed high antifungal activity, with benzothiazole and 2,4-dimethyl-6-tert-butylphenol being the most potent compounds. These results indicate that the VOCs produced by B. velezensis CT32 have the potential to be used as a biofumigant for management of vascular wilt pathogens.

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Inhibition of plant pathogenic fungi by endophytic Trichoderma spp. through mycoparasitism and volatile organic compounds

Microbiological Research ◽

10.1016/j.micres.2020.126595 ◽

2021 ◽

Vol 242 ◽

pp. 126595

Author(s):

P. Rajani ◽

C. Rajasekaran ◽

M.M. Vasanthakumari ◽

Shannon B. Olsson ◽

G. Ravikanth ◽

...

Keyword(s):

Volatile Organic Compounds ◽

Organic Compounds ◽

Pathogenic Fungi ◽

Plant Pathogenic Fungi ◽

Trichoderma Spp ◽

Volatile Organic

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Annulohypoxylon sp. FPYF3050 produces volatile organic compounds against the pine wood nematode, Bursaphelenchus xylophilus

Nematology ◽

10.1163/15685411-00003303 ◽

2020 ◽

Vol 22 (3) ◽

pp. 245-255

Author(s):

Hongchang Li ◽

Guiming Dou ◽

Mengge Gao ◽

Fei Ren ◽

Ruhua Li ◽

...

Keyword(s):

Volatile Organic Compounds ◽

Organic Compounds ◽

Inhibitory Effect ◽

Bursaphelenchus Xylophilus ◽

Gas Chromatography Mass Spectrometry ◽

Pine Wood Nematode ◽

Pine Wood ◽

Volatile Organic ◽

Nematode Eggs ◽

Petri Plate

Summary Natural volatiles released by the fungus, Annulohypoxylon sp. FPYF3050, were evaluated against the pine wood nematode (PWN), Bursaphelenchus xylophilus. Our results showed that volatile organic compounds (VOCs) caused 64.1 and 58.4% mortality of second-stage juveniles (J2) and mixed-stages (eggs, J2, third- and fourth-stage juveniles, and adults) of populations of PWN, but no inhibitive effects were detected on nematode eggs in the experiment. Analysis of the gases within the Petri plate by gas chromatography-mass spectrometry (GC-MS) showed a yield of an unique volatile with dominant 1,8-cineole in 77.4% relative area (RA) after 72 h treatment of nematodes with Annulohypoxylon sp. FPYF3050 and Botrytis cinerea. The commercial 1,8-cineole at concentrations of 2, 5, 10 and 15 μl ml−1 was applied to examine nematicidal activity. The results showed that 1,8-cineole had a 40-100% inhibition on the nematode eggs during 48 h treatment, more than 82.9% mortality of J2 after 24 h, 48 h and 96 h, and 18.7-91.9% mortality of the mixed-stage population, depending on the period after exposure. This result indicates that 1,8-cineole in the volatile gas emissions of Annulohypoxylon sp. FPYF3050 may play a crucial inhibitory effect on the pine wood nematode The nematicidal volatile gas from fungi may provide a useful biocontrol agent for controlling B. xylophilus.

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