scholarly journals Effect of Ethanol Vapor Treatment on the Growth of Alternaria alternata and Botrytis cinerea and Defense-Related Enzymes of Fungi-Inoculated Blueberry During Storage

2021 ◽  
Vol 12 ◽  
Author(s):  
Yaru Ji ◽  
Wenzhong Hu ◽  
Jia Liao ◽  
Zhilong Xiu ◽  
Aili Jiang ◽  
...  
Keyword(s):  
Botrytis Cinerea ◽  
Alternaria Alternata ◽  
Mycelial Growth ◽  
Ethanol Vapor ◽  
Defense Responses ◽  
Dependent Manner ◽  
Practical Application ◽  
Structure And Ultrastructure ◽  
Dose Dependent ◽  
Vapor Treatment

The aim of the present study was to investigate the effects of ethanol vapor on the inhibition of Alternaria alternata and Botrytis cinerea in postharvest blueberry and the induction of defense-related enzymes (DREs) activities in fungi-inoculated blueberries stored at 0±0.5°C for 16days. Results indicated that ethanol vapor markedly inhibited the mycelial growth of A. alternata and B. cinerea in a dose-dependent manner, with inhibition rates of 9.1% (250μlL−1), 36.4% (500μlL−1), and 5.5% (1,000μlL−1) on A. alternata and 14.2% (250μlL−1), 44.7% (500μlL−1), and 76.6% (1,000μlL−1) on B. cinerea, respectively. Meanwhile, ethanol vapor also enhanced the activities of DREs in fungi-inoculated blueberries, including β-1,3-glucanase (GLU), chitinase (CHI), phenylalnine ammonialyase (PAL), peroxidase (POD), and polyphenol oxidase (PPO). In particular, 500μlL−1 ethanol vapor increased the activities of DREs by 84.7% (GLU), 88.0% (CHI), 37.9% (PAL), 85.5% (POD), and 247.0% (PPO) in A. alternata-inoculated blueberries and 103.8% (GLU), 271.1% (CHI), 41.1% (PAL), 148.3% (POD), and 74.4% (PPO) in B. cinerea-inoculated blueberries, respectively. But, the activity of PPO was decreased by 55.2 and 31.9% in 500μlL−1 ethanol-treated blueberries inoculated with A. alternata and B. cinerea, respectively, after 8days of storage. Moreover, the surface structure and ultrastructure of 500μlL−1 ethanol-treated blueberry fruit cells were more integrated than those of other treatments. The findings of the present study suggest that ethanol could be used as an activator of defense responses in blueberry against Alternaria and Botrytis rots, by activating DREs, having practical application value in the preservation of postharvest fruit and vegetables.

scholarly journals Antifungal Studies of Selected Essential Oils and a Commercial Formulation against Botrytis Cinerea

2013 ◽  
Vol 2 (1) ◽  
pp. 217 ◽  
Author(s):  
Oyeboade Adebayo ◽  
Thao Dang ◽  
André Bélanger ◽  
Shahrokh Khanizadeh
Keyword(s):  
Essential Oils ◽  
Botrytis Cinerea ◽  
Antifungal Agents ◽  
Control Strategies ◽  
Grey Mould ◽  
Dependent Manner ◽  
Contact Phase ◽  
Commercial Formulation ◽  
Plant Disease Control ◽  
Dose Dependent

<p>Growing concerns about food safety and environmental protection have created a need for new and safe plant disease control strategies. The aim of this study was to find an alternative to synthetic fungicides currently used in the control of the devastating fungal pathogen <em>Botrytis cinerea</em> Pers., the causal agent of grey mould disease of strawberry (<em>Fragariaananassa </em>Duch). The antifungal activity of the essential oils of <em>Origanumvulgare</em> L., <em>Monardadidyma</em> L. and of a commercial formulation of thyme oil (Gloves Off®) was investigated against <em>B. cinerea</em> and compared with controls. Contact phase effects of different concentrations of the essential oils and commercial formulation were found to inhibit the growth of <em>B. cinerea</em> in a dose dependent manner. Complete growth inhibition of the pathogen was recorded at 200 µg/ml of ‘Gloves Off®’. The mycelial growth of the pathogen was significantly reduced at the highest concentration of the essential oils of <em>O. vulgare</em><em> </em>and<em> M.</em><em> didyma</em> tested, which was 51.2 µg/ml. Spore germination and germ tube elongation were also inhibited by the essential oils and Gloves Off®. Light microscopic observations revealed that the essential oils caused morphological degenerations, such as cytoplasmic coagulation, hyphal shrivelling and protoplast leakage of the fungal hyphae. The essential oils of <em>O.</em><em> vulgare</em> L. and <em>M.</em><em> didyma</em> L. are promising, antifungal agents against <em>B. cinerea</em>similar to the commercial formulation ‘Gloves Off®’.</p>

scholarly journals Assessing the effectiveness of oxathiapiprolin towards Phytophthora agathidicida, the causal agent of kauri dieback disease

FEMS Microbes ◽  
2021 ◽  
Author(s):  
Randy F Lacey ◽  
Michael J Fairhurst ◽  
Kaitlyn J Daley ◽  
Te Amohaere Ngata-Aerengamate ◽  
Haileigh R Patterson ◽  
...  
Keyword(s):  
Life Cycle ◽  
New Zealand ◽  
Mycelial Growth ◽  
Phytophthora Species ◽  
Effective Concentration ◽  
Dependent Manner ◽  
Life Cycle Stages ◽  
Leaf Infection ◽  
Dieback Disease ◽  
Dose Dependent

Abstract Phytophthora species cause disease and devastation of plants in ecological and horticultural settings worldwide. A recently identified species, P. agathidicida, infects and ultimately kills the treasured kauri trees (Agathis australis) that are endemic to New Zealand. Currently there are few options for managing kauri dieback disease. In this study, we sought to assess the toxicity of the oomycide oxathiapiprolin against several life cycle stages of two geographically distinct P. agathidicida isolates. The effective concentration to inhibit 50% of mycelial growth (EC50) was determined to be approximately 0.1 ng/ml, indicating that P. agathidicida mycelia are more sensitive to oxathiapiprolin than those from most other Phytophthora species that have been studied. Oxathiapiprolin was also highly effective at inhibiting the germination of zoospores (EC50 = 2–9 ng/ml for the two isolates) and oospores (complete inhibition at 100 ng/ml). In addition, oxathiapiprolin delayed the onset of detached kauri leaf infection in a dose-dependent manner. Collectively, the results presented here highlight the significant potential of oxathiapiprolin as a tool to aid in the control of kauri dieback disease.

scholarly journals Pyocyanin pigment from Pseudomonas aeruginosa modulates innate immune defenses in macrophages

2021 ◽  
Author(s):  
Yasmine Mahgoub ◽  
Rida Arif ◽  
Susu Zughaier
Keyword(s):  
Nitric Oxide ◽  
Pseudomonas Aeruginosa ◽  
Immunocompromised Host ◽  
Defense Responses ◽  
Innate Immune ◽  
Dependent Manner ◽  
Functional Responses ◽  
Nitric Oxide Release ◽  
Immune Defenses ◽  
Dose Dependent

Background: Pseudomonas aeruginosa is a well-known opportunistic pathogen. The gram-negative bacillus, commonly associated with hospital-acquired infections, utilizes the host’s impaired immune responses to establish infection. Of its many virulence factors, pyocyanin is essential for P. aeruginosa to establish its full infectivity. Macrophages act as sentinels of the innate immune system, as well as play other roles in homeostasis, tissue remodeling, and bridging between the innate and adaptive immune systems. Aim: This study aimed to investigate the effects of pyocyanin on macrophage innate immune defenses by assessing the function of macrophages treated with pyocyanin and TLR ligands. Phagocytosis of opsonized zymosan, LPS-induced nitric oxide release and cytokine release were used as measures of functional responses. Results: This study found that pyocyanin inhibited phagocytosis-induced ROS release in a dose-dependent manner and reduced nitric oxide release from macrophages induced with P. aeruginosa LPS. In addition, pyocyanin modulated cytokines and chemokines release from macrophages exposed to P. aeruginosa LPS in a dose-dependent manner. Pyocyanin significantly enhanced IL-1β release as well as several chemokines. Therefore, pyocyanin facilitates Pseudomonas aeruginosa to persevere in the immunocompromised host through modulating macrophage’s innate immune defenses. Conclusion: Pyocyanin inhibits macrophage functional defense responses to facilitate Pseudomonas aeruginosa infection.

Effects of equilibrium relative humidity on in vitro growth of Botrytis cinerea and Alternaria alternata

1996 ◽  
Vol 36 (3) ◽  
pp. 383 ◽  
Author(s):  
S Alam ◽  
D Joyce ◽  
A Wearing
Keyword(s):  
Relative Humidity ◽  
Liquid Medium ◽  
Botrytis Cinerea ◽  
Alternaria Alternata ◽  
Mycelial Growth ◽  
Dry Matter ◽  
Diameter Growth ◽  
Colony Diameter ◽  
Equilibrium Relative Humidity

Mycelial growth in vitro of 2 fungal pathogens responsible for postharvest loss of horticulture produce, Botrytis cinerea and Alternaria alternata, was related to equilibrium relative humidity (e.r.h) at ambient temperature (20�C) using solutes to adjust the 'osmotic water potential' of the growth medium. Colony diameter growth of B. cinerea and A. alternata on solid medium (1/2 potato dextrose agar) was initially stimulated slightly when the e.r.h. was decreased from 99.7 (unamended medium) to 99.3% (-0.4 to -1.0 MPa). Thereafter, colony diameter growth continually decreased as a function of reducing e.r.h. over the range 99.3-94.3% e.r.h. (-1.0 to -8.0 MPa). Similar trends were recorded with both pathogens for their dry matter growth in liquid medium (Oxoid Czapek Dox) as a function of osmotic potential. Initial stimulation of dry matter growth at -1.0 MPa (equivalent to 99.3% e.r.h.) was not evident in liquid medium. Fungal growth data suggest that postharvest mycelial growth of Botrytis cinerea and Alternaria alternata on wounds, senescing tissue or secretions such as cell sap or nectar could be restricted through control of e.r.h. in packages of horticulture produce.

scholarly journals Hormetic Effects of Flusilazole Preconditioning on Mycelial Growth and Virulence of Sclerotinia sclerotiorum

Plant Disease ◽  
2018 ◽  
Vol 102 (6) ◽  
pp. 1165-1170 ◽  
Author(s):  
Xiaoming Lu ◽  
Shun He ◽  
Hongju Ma ◽  
Jianhong Li ◽  
Fuxing Zhu
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Mycelial Growth ◽  
Dose Range ◽  
Pathogenic Fungi ◽  
Phytopathogenic Fungi ◽  
Dependent Manner ◽  
Inhibitory Effects ◽  
Mycelia Growth ◽  
Dmi Fungicides ◽  
Dose Dependent

Hormetic effects of fungicides are highly relevant to fungicide applications and management of plant-pathogenic fungi. Preconditioning (i.e., early exposure to relatively low doses of a toxicant) is a special form of hormesis, and fungicide preconditioning of phytopathogenic fungi is inevitable in the field. The present study showed that spraying the demethylation inhibitor (DMI) fungicide flusilazole at 0.1 µg/ml had stimulatory effects on the virulence of Sclerotinia sclerotiorum inoculated at 1 and 24 h after spraying. Flusilazole sprayed at 10 µg/ml showed inhibitory effects on the virulence of S. sclerotiorum inoculated during the first 3 days after spraying. Inoculations on the 5th, 7th, and 10th day after spraying did not show any significant inhibitory or stimulatory effects on the virulence. After growing for 2 days on potato dextrose agar (PDA) amended with flusilazole at a dose range from 0.0005 to 0.25 µg/ml as preconditioning treatments, mycelia were transferred onto PDA without fungicide and subsequent mycelial growth was slower than the nonpreconditioned control. However, after the preconditioned colonies were transferred onto PDA supplemented with flusilazole at 0.2 µg/ml, percent stimulations of mycelia growth compared with the control had a parabolic shape across the preconditioning flusilazole concentration range. Similarly, the mycelial growth of the preconditioned mycelial plugs on PDA amended with other DMI fungicides (prochloraz or tebuconazole) also showed a typical hormetic response, whereas mycelial growth on PDA amended with carbendazim or dimethachlone was inhibited in a dose-dependent manner. Preconditioning S. sclerotiorum with flusilazole on rapeseed plants elicited virulence stimulations in a dose-dependent manner similar to those on mycelial growth on PDA. After disease lesions developed on rapeseed leaves sprayed with flusilazole as the preconditioning treatment were inoculated onto rapeseed plants, virulence was inhibited on leaves without fungicide or sprayed with carbendazim or dimethachlone compared with the nonpreconditioned control, whereas virulence was stimulated on leaves sprayed with flusilazole, prochloraz, or tebuconazole, and the maximum percent stimulation was 10.2%. These results will advance our understanding of hormetic effects of fungicides and of preconditioning hormesis in particular.

scholarly journals The PIFs Redundantly Control Plant Defense Response against Botrytis cinerea in Arabidopsis

Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1246
Author(s):  
Shengyuan Xiang ◽  
Songguo Wu ◽  
Haiyan Zhang ◽  
Minghui Mou ◽  
Yanli Chen ◽  
...  
Keyword(s):  
Botrytis Cinerea ◽  
Defense Response ◽  
Plant Defenses ◽  
Control Plant ◽  
Light Response ◽  
Defense Responses ◽  
Dependent Manner ◽  
In The Wild ◽  
Defense Response Genes ◽  
Wild Type Control

Endogenous and exogenous signals are perceived and integrated by plants to precisely control defense responses. As a crucial environmental cue, light reportedly plays vital roles in plant defenses against necrotrophic pathogens. Phytochrome-interacting factor (PIF) is one of the important transcription factors which plays essential roles in photoreceptor-mediated light response. In this study, we revealed that PIFs negatively regulate plant defenses against Botrytis cinerea. Gene expression analyses showed that the expression level of a subset of defense-response genes was higher in pifq (pif1/3/4/5) mutants than in the wild-type control, but was lower in PIF-overexpressing plants. Chromatin immunoprecipitation assays proved that PIF4/5 binds directly to the ETHYLENE RESPONSE FACTOR1 (ERF1) promoter. Moreover, genetic analyses indicated that the overexpression of ERF1 dramatically rescues the susceptibility of PIF4-HA and PIF5-GFP transgenic plants, and that PIF controls the resistance to B. cinerea in a COI1- and EIN2-dependent manner. Our results provide compelling evidence that PIF, together with the jasmonate/ethylene pathway, is important for plant resistance to B. cinerea.

scholarly journals Assessing the effectiveness of oxathiapiprolin towards Phytophthora agathidicida, the causal agent of kauri dieback disease

2021 ◽  
Author(s):  
Randy F. Lacey ◽  
Michael J. Fairhurst ◽  
Kaitlyn J. Daley ◽  
Te Amohaere Ngata-Aerengamate ◽  
Haileigh R. Patterson ◽  
...  
Keyword(s):  
New Zealand ◽  
Mycelial Growth ◽  
Effective Concentration ◽  
Complete Inhibition ◽  
Dependent Manner ◽  
Significant Potential ◽  
Leaf Infection ◽  
Half Maximal Effective Concentration ◽  
Dieback Disease ◽  
Dose Dependent

AbstractPhytophthora species cause disease and devastation of plants in ecological and horticultural settings worldwide. A recently identified species, P. agathidicida, infects and ultimately kills the treasured kauri trees that are endemic to New Zealand. Currently there are few options for controlling or treating P. agathidicida. In this study, we sought to assess the toxicity of the oomycide oxathiapiprolin against several lifecycle stages of two geographically distinct P. agathidicida isolates. Half maximal effective concentration (EC50) values were determined to be approximately 0.1 ng/ml for inhibiting mycelial growth, indicating that P. agathidicida mycelia are more sensitive to oxathiapiprolin than those from most other Phytophthora species that have been studied. Oxathiapiprolin was also highly effective at inhibiting the germination of zoospores (EC50 = 2-9 ng/ml for the two isolates) and oospores (complete inhibition at 100 ng/ml). In addition, oxathiapiprolin delayed the onset of detached kauri leaf infection in a dose-dependent manner. Collectively, the results presented here highlight the significant potential of oxathiapiprolin as a tool to aid in the control of kauri dieback disease.

scholarly journals In vitro inhibitory effect of herbal organic formulations on mycelial growth of Pea wilt pathogen Fusarium oxysporum

2020 ◽  
Vol 5 (01) ◽  
pp. 110-112
Author(s):  
W. Tampakleima Chanu ◽  
Bireswar Sinha ◽  
Kota Chakrapani
Keyword(s):  
Fusarium Oxysporum ◽  
Fusarium Wilt ◽  
Mycelial Growth ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
In Vitro Growth ◽  
Inhibitory Activities ◽  
Organic Formulations ◽  
Dose Dependent

The objective of this study was to determine inhibitory activities of three herbal organic formulations (fungidote, viridote, and bacteridote) on in vitro growth of Fusarium oxysporum causing Fusarium wilt of a pea in Manipur. In vitro results showed that these formulations inhibited the mycelial growth of F. oxysporum in a dose-dependent manner. Fungidote was found to be the most in reducing mycelial growth compared to the other two formulations at different concentrations. These results underpin that formulations could be used in eco-friendly disease management of Fusarium wilt of a pea.

scholarly journals Antifungal Effect of Magnolol and Honokiol from Magnolia officinalis on Alternaria alternata Causing Tobacco Brown Spot

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2140 ◽  
Author(s):  
Ya-Han Chen ◽  
Mei-Huan Lu ◽  
Dong-Sheng Guo ◽  
Ying-Yan Zhai ◽  
Dan Miao ◽  
...  
Keyword(s):  
Alternaria Alternata ◽  
Pathogenic Fungi ◽  
Brown Spot ◽  
Cell Membrane Permeability ◽  
Penicillium Expansum ◽  
Dependent Manner ◽  
Antifungal Effect ◽  
Alternaria Dauci ◽  
Magnolia Officinalis ◽  
Dose Dependent

In this study, two phenol compounds, magnolol and honokiol, were extracted from Magnolia officinalis and identified by LC-MS, 1H- and 13C-NMR. The magnolol and honokiol were shown to be effective against seven pathogenic fungi, including Alternaria alternata (Fr.) Keissl, Penicillium expansum (Link) Thom, Alternaria dauci f.sp. solani, Fusarium moniliforme J. Sheld, Fusarium oxysporum Schltdl., Valsa mali Miyabe & G. Yamada, and Rhizoctonia solani J.G. Kühn, with growth inhibition of more than 57%. We also investigated the mechanisms underlying the potential antifungal activity of magnolol and honokiol. The results showed that they inhibited the growth of A. alternata in a dose-dependent manner. Moreover, magnolol and honokiol treatment resulted in distorted mycelia and increased the cell membrane permeability of A. alternata, as determined by conductivity measurements. These results suggest that magnolol and honokiol are potential antifungal agents for application against plant fungal diseases.

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