scholarly journals Hormetic Effects of Carbendazim on the Virulence of Botrytis cinerea

Plant Disease ◽  
2018 ◽  
Vol 102 (5) ◽  
pp. 886-891 ◽  
Author(s):  
Menglong Cong ◽  
Shun He ◽  
Hongju Ma ◽  
Guoqing Li ◽  
Fuxing Zhu
Keyword(s):  
Hydrogen Peroxide ◽  
Disease Management ◽  
Botrytis Cinerea ◽  
Time Course ◽  
Plant Pathogens ◽  
Pathogenic Fungus ◽  
Physiological Mechanism ◽  
Potato Dextrose Agar ◽  
Direct Stimulation ◽  
Sublethal Doses

The ascomycete plant-pathogenic fungus Botrytis cinerea infects more than 1,400 plant species worldwide. Stimulatory effects of sublethal doses of fungicides on plant pathogens are of close relevance to disease management. In the present study, stimulatory effects of carbendazim on the virulence of B. cinerea to cucumber plants were investigated. Spraying carbendazim on cucumber plants at 3 to 200 μg/ml had stimulatory effects on the virulence of carbendazim-resistant isolates of B. cinerea and the maximum percent stimulations were 16.7 and 13.5% for isolates HBtom451 and HBstr491, respectively. Preconditioned mycelia (i.e., mycelia grown on potato dextrose agar [PDA] amended with carbendazim at concentrations of 10, 50, or 200 μg/ml) also showed increased virulence, and the maximum percent stimulations for isolates HBtom451 and HBstr491 were 7.9 and 9.5%, respectively. Compared with mycelia grown on PDA without carbendazim, virulence stimulation magnitudes of spraying carbendazim on leaves increased moderately but the concentrations of carbendazim that elicited the maximum stimulation increased 20- and 8-fold for preconditioned isolates HBtom451 and HBstr491, respectively. The time course of infection indicated that virulence stimulation was mediated by a direct stimulation mechanism. Studies of the physiological mechanism for stimulation demonstrated that carbendazim had no significant effects on tolerance to hydrogen peroxide, or on oxalic acid production in B. cinerea. These studies will deepen our understanding of quantitative features of hormetic effects of sublethal doses of fungicides on plant pathogens.

scholarly journals Stimulatory Effects of Flusilazole on Virulence of Sclerotinia sclerotiorum

Plant Disease ◽  
2018 ◽  
Vol 102 (1) ◽  
pp. 197-201 ◽  
Author(s):  
Xiaoming Lu ◽  
Ran Zhang ◽  
Menglong Cong ◽  
Jianhong Li ◽  
Fuxing Zhu
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Radial Growth ◽  
Time Course ◽  
Physiological Mechanism ◽  
Infection Process ◽  
Potato Dextrose Agar ◽  
Oxygen Species ◽  
Potential Mechanism ◽  
Direct Stimulation ◽  
Demethylation Inhibitor

Flusilazole, a member of the demethylation inhibitor fungicides, is highly efficacious for control of Sclerotinia sclerotiorum. To achieve judicious applications of flusilazole, its hormetic effects on virulence of S. sclerotiorum were investigated. Flusilazole sprayed at concentrations from 0.02 to 0.5 μg/ml caused statistically significant (P < 0.05) stimulatory effects on virulence of S. sclerotiorum to potted rapeseed plants, and the maximum stimulation magnitudes were 11.0 and 10.7% for isolates GS-7 and HN-24, respectively. Studies on the time course of the infection process showed that a stimulatory effect on virulence could be discerned at 18 h postinoculation, indicating a direct stimulation mechanism rather than an overcompensation for initial inhibitions. In order to determine whether the stimulations were caused mainly by effects of flusilazole on S. sclerotiorum or on rapeseed plants, mycelia grown on flusilazole-amended potato dextrose agar (PDA) media were inoculated on leaves of rapeseed plants without spraying the fungicide. Mycelium radial growth on PDA supplemented with flusilazole at concentrations from 0.005 to 0.16 μg/ml was inhibited by 10.11 to 48.7% for isolate GS-7 and by 4.1 to 24.9% for isolate HN-24. Observations with a scanning electron microscope showed that flusilazole in PDA at 0.04 and 0.08 μg/ml caused slightly deformed mycelia and twisted mycelial tips. Nevertheless, after inoculating on leaves of potted rapeseed plants, virulence of the inhibited mycelia was statistically significantly (P < 0.05) greater than that of the nontreated control, and the maximum stimulation magnitudes were 16.2 and 19.8% for isolates GS-7 and HN-24, respectively. Studies on a physiological mechanism for virulence stimulations showed that tolerance to hydrogen peroxide did not increase significantly for mycelia grown on flusilazole-amended PDA, thus excluding the possibility of tolerance to reactive oxygen species as a potential mechanism for virulence stimulations.

scholarly journals A Novel Partitivirus in the Hypovirulent Isolate QT5-19 of the Plant Pathogenic Fungus Botrytis cinerea

Viruses ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 24 ◽  
Author(s):  
Md Kamaruzzaman ◽  
Guoyuan He ◽  
Mingde Wu ◽  
Jing Zhang ◽  
Long Yang ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Botrytis Cinerea ◽  
Pathogenic Fungus ◽  
Amino Acid Sequences ◽  
Potato Dextrose Agar ◽  
Rna Dependent Rna Polymerase ◽  
Virus Particles ◽  
Genome Feature ◽  
Infected Tobacco ◽  
Hyphal Contact

A pink isolate (QT5-19) of Botrytis cinerea was compared with three gray isolates of B. cinerea for growth and morphogenesis on potato dextrose agar (PDA), and for pathogenicity on tobacco. A double-stranded (ds) RNA mycovirus infecting QT5-19 was identified based on its genome feature and morphology of the virus particles. The results showed that QT5-19 grew rapidly and established flourishing colonies as the gray isolates did. However, it is different from the gray isolates, as it failed to produce conidia and sclerotia asthe gray isolates did. QT5-19 hardly infected tobacco, whereas the gray isolates aggressively infected tobacco. Two dsRNAs were detected in QT5-19, dsRNA 1 and dsRNA 2, were deduced to encode two polypepetides with homology to viral RNA-dependent RNA polymerase (RdRp) and coat protein (CP), respectively. Phylogenetic analysis of the amino acid sequences of RdRp and CP indicated that the two dsRNAs represent the genome of a novel partitivirus in the genus Alphapartitivirus, designated here as Botrytis cinerea partitivirus 2 (BcPV2). BcPV2 in QT5-19 was successfully transmitted to the three gray isolates through hyphal contact. The resulting BcPV2-infected derivatives showed rapid growth on PDA with defects in conidiogenesis and sclerogenesis, and hypovirulence on tobacco. This study suggests that BcPV2 is closely associated with hypovirulence of B. cinerea.

scholarly journals Stimulatory Effects of Sublethal Doses of Carbendazim on the Virulence and Sclerotial Production of Botrytis cinerea

Plant Disease ◽  
2019 ◽  
Vol 103 (9) ◽  
pp. 2385-2391 ◽  
Author(s):  
Menglong Cong ◽  
Bao Zhang ◽  
Kunyu Zhang ◽  
Guoqing Li ◽  
Fuxing Zhu
Keyword(s):  
Nadph Oxidase ◽  
Botrytis Cinerea ◽  
Mycelial Growth ◽  
Pectin Methylesterase ◽  
Potato Dextrose Agar ◽  
Low Doses ◽  
Xylanase Gene ◽  
Oxidase Gene ◽  
Expression Levels ◽  
Sublethal Doses

Stimulatory effects of low doses of fungicides on the virulence of phytopathogens have profound implications for applications of fungicides. The present study demonstrated that carbendazim sprayed at 0.001 to 0.03 μg/ml had stimulatory effects on the virulence of mycelia of Botrytis cinerea, and the maximum percent stimulations were 15.5 and 21.4% for isolates HB459 and HB536, respectively. Potato dextrose agar (PDA) amended with carbendazim at 0.01, 0.02, and 0.05 μg/ml inhibited mycelial growth of isolate HB536 by 0.8, 10.0, and 30.6%, respectively. However, after the inhibited mycelia were inoculated on cucumber leaves, virulence increased by 10.1, 12.9, and 10.8%, respectively. With respect to sclerotial production, carbendazim at 0.005 and 0.02 μg/ml in PDA significantly (P < 0.05) increased, while at 0.1 μg/ml significantly (P < 0.05) reduced the sclerotial number and weight of both isolates compared with nontreated controls. Conidia germination percentages slightly yet statistically significantly (P < 0.05) increased after being inoculated on PDA amended with carbendazim at 0.001 and 0.005 μg/ml. Carbendazim at 0.001∼0.02 μg/ml, either sprayed on cucumber leaves or cosuspended with conidia, exerted significantly (P < 0.05) stimulatory effects on the virulence of B. cinerea conidia. Mechanism studies showed that sublethal doses of carbendazim did not increase the expression levels of pathogenicity-related pectin methylesterase gene Bcpme1, endopolygalacturonase gene Bcpg2, cutinase gene CutA, xylanase gene Xyn11A, or NADPH oxidase gene BcnoxA.

scholarly journals Hormetic Effects of Mixtures of Carbendazim and Iprodione on the Virulence of Botrytis cinerea

Plant Disease ◽  
2019 ◽  
Vol 103 (1) ◽  
pp. 95-101 ◽  
Author(s):  
Menglong Cong ◽  
Shun He ◽  
Jun Zhang ◽  
Chaoxi Luo ◽  
Fuxing Zhu
Keyword(s):  
Botrytis Cinerea ◽  
Mycelial Growth ◽  
Plant Pathogens ◽  
Pathogenic Fungi ◽  
Potato Dextrose Agar ◽  
Inhibitory Effects ◽  
Additive Interaction ◽  
Physiological Mechanisms ◽  
Fungicide Mixtures ◽  
Stimulation Of

Hormetic effects of fungicides on mycelial growth and virulence of plant pathogenic fungi have been reported, but the effects of fungicide mixtures on virulence hormesis of plant pathogens remain to be investigated. In this study, hormetic effects of mixtures of carbendazim and iprodione on the virulence of two carbendazim-resistant isolates of Botrytis cinerea were determined. Spraying carbendazim alone at 3 to 800 μg/ml exhibited hormetic effects on virulence to cucumber leaves, and carbendazim at 10 μg/ml had the maximum stimulation of 16.7% for isolate HBtom451. Spraying iprodione alone at 0.0001 to 0.0625 μg/ml exhibited hormetic effects on virulence, and iprodione at 0.025 μg/ml had the maximum stimulation of 18.7% for isolate HBtom451. However, spraying simultaneously carbendazim at 800 μg/ml and iprodione at 0.0625 μg/ml showed inhibitory effects on virulence to cucumber leaves. The mixture of carbendazim at 3 μg/ml and iprodione at 0.0001 μg/ml had much higher virulence stimulations than either fungicide at the same concentration alone. The maximum stimulation for the mixtures occurred at 10 and 0.0005 μg/ml for carbendazim and iprodione, respectively, and these concentrations were much lower than the concentration of their respective fungicide alone eliciting the maximum stimulations. The maximum stimulation amplitude for the mixture was slightly higher than that of each fungicide alone. These results demonstrated that carbendazim and iprodione mainly had dose-additive rather than amplitude-additive interactions when sprayed simultaneously with regard to virulence stimulations. Studies on virulence stimulations for mycelia treated with fungicide in potato dextrose agar showed that the maximum stimulation for the mixtures occurred at concentrations much lower than the concentration of carbendazim alone, indicating a dose-additive interaction when compared with carbendazim hormesis. Studies on potential physiological mechanisms of hormesis showed that increased tolerance to H2O2 may be one of the mechanisms for virulence hormesis for the mixtures of iprodione and carbendazim. These studies will advance our understanding of hormesis of fungicide mixtures.

scholarly journals The polyphagous plant pathogenic fungus Botrytis cinerea encompasses host-specialized and generalist populations

2019 ◽  
Author(s):  
Alex Mercier ◽  
Florence Carpentier ◽  
Clémentine Duplaix ◽  
Annie Auger ◽  
Jean-Marc Pradier ◽  
...  
Keyword(s):  
Genetic Analysis ◽  
Botrytis Cinerea ◽  
Population Genetic ◽  
Plant Pathogens ◽  
Pathogenic Fungus ◽  
Spatial Optimization ◽  
Agricultural Landscapes ◽  
Host Specialization ◽  
Population Genetic Analysis ◽  
Fungal Plant Pathogens

AbstractThe host plant is often the main variable explaining population structure in fungal plant pathogens, because specialization contributes to reduce gene flow between populations associated with different hosts. Previous population genetic analysis revealed that French populations of the grey mould pathogen Botrytis cinerea were structured by hosts tomato and grapevine, suggesting host specialization in this highly polyphagous pathogen. However, these findings raised questions about the magnitude of this specialization and the possibility of specialization to other hosts. Here we report specialization of B. cinerea populations to tomato and grapevine hosts but not to other tested plants. Population genetic analysis revealed two pathogen clusters associated with tomato and grapevine, while the other clusters co-occurred on hydrangea, strawberry and bramble. Measurements of quantitative pathogenicity were consistent with host specialization of populations found on tomato, and to a lesser extent, populations found on grapevine. Pathogen populations from hydrangea and strawberry appeared to be generalist, while populations from bramble may be weakly specialized. Our results suggest that the polyphagous B. cinerea is more accurately described as a collection of generalist and specialist individuals in populations. This work opens new perspectives for grey mold management, while suggesting spatial optimization of crop organization within agricultural landscapes.

scholarly journals Time Course of Carbendazim Stimulation on Pathogenicity of Sclerotinia sclerotiorum Indicates a Direct Stimulation Mechanism

Plant Disease ◽  
2016 ◽  
Vol 100 (7) ◽  
pp. 1454-1459 ◽  
Author(s):  
Ya-Li Di ◽  
Xiao-Ming Lu ◽  
Zu-Qing Zhu ◽  
Fu-Xing Zhu
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Time Course ◽  
Underlying Mechanism ◽  
Potato Dextrose Agar ◽  
Cell Wall Degrading Enzymes ◽  
Direct Stimulation ◽  
Disease Symptoms ◽  
Fungal Pathogenicity ◽  
Biochemical Mechanisms ◽  
Scanning Electron

Previous studies have demonstrated that subtoxic doses of carbendazim have a stimulatory effect on pathogenicity of Sclerotinia sclerotiorum on rapeseed plants. The present study focused on the time-course profile of the stimulatory effect and its relevance to stimulation mechanisms. At 12 h postinoculation (HPI), initial necrotic lesions were visible only for rapeseed leaves treated with carbendazim at 0.2 and 1 μg/ml, whereas no disease symptoms were observed for the nontreated control. At 18 HPI, carbendazim stimulation on pathogenicity was more obvious than at 12 HPI. Study with scanning electron microscopy demonstrated that no discernable differences in the development of disease symptoms could be detected at 8 HPI. However, at 12 HPI, necrotic symptoms of the epidermal cells were apparent only for leaves sprayed with carbendazim. These results indicated that stimulations on pathogenicity occurred in the first 12 h, implying that direct stimulation rather than overcompensation to the disruption of homeostasis was likely to be the underlying mechanism for pathogenicity stimulation. Greenhouse experiments showed that spraying carbendazim at 400 μg/ml on potted rapeseed plants had statistically significant (P < 0.05) stimulations on pathogenicity for inoculations at 1, 3, 5, and 7 days after application (DAA). The stimulation action eventually disappeared for inoculations at 14 DAA. Mycelia grown on potato dextrose agar (PDA) supplemented with carbendazim at 400 μg/ml were more pathogenic than the nontreated control. However, after additional growth of the mycelia on fungicide-free PDA for 2 days, the stimulatory effect disappeared completely, indicating that carbendazim was indispensable for pathogenicity stimulations. Studies on biochemical mechanisms indicated that cell-wall-degrading enzymes such as cellulase, pectinase, and polygalacturonase were not involved in pathogenicity stimulations. These results will advance our understanding of the nature and mechanisms of fungicide stimulation on fungal pathogenicity and, thus, are valuable for judicious applications of fungicides.

scholarly journals Clathrin Is Important for Virulence Factors Delivery in the Necrotrophic Fungus Botrytis cinerea

2021 ◽  
Vol 12 ◽  
Author(s):  
Eytham Souibgui ◽  
Christophe Bruel ◽  
Mathias Choquer ◽  
Amélie de Vallée ◽  
Cindy Dieryckx ◽  
...  
Keyword(s):  
Botrytis Cinerea ◽  
Virulence Factors ◽  
Essential Role ◽  
Plant Pathogens ◽  
Pathogenic Fungus ◽  
Hydrolytic Enzymes ◽  
Pathogenic Fungi ◽  
Dominant Negative ◽  
Intracellular Vesicles

Fungi are the most prevalent plant pathogens, causing annually important damages. To infect and colonize their hosts, they secrete effectors including hydrolytic enzymes able to kill and macerate plant tissues. These secreted proteins are transported from the Endoplasmic Reticulum and the Golgi apparatus to the extracellular space through intracellular vesicles. In pathogenic fungi, intracellular vesicles were described but their biogenesis and their role in virulence remain unclear. In this study, we report the essential role of clathrin heavy chain (CHC) in the pathogenicity of Botrytis cinerea, the agent of gray mold disease. To investigate the importance of this protein involved in coat vesicles formation in eukaryotic cells, a T-DNA insertional mutant reduced in the expression of the CHC-encoding gene, and a mutant expressing a dominant-negative form of CHC were studied. Both mutants were strongly affected in pathogenicity. Characterization of the mutants revealed altered infection cushions and an important defect in protein secretion. This study demonstrates the essential role of clathrin in the infectious process of a plant pathogenic fungus and more particularly its role in virulence factors delivery.

scholarly journals Transcription Profiling ofCandida albicansCells Undergoing the Yeast-to-Hyphal Transition

2002 ◽  
Vol 13 (10) ◽  
pp. 3452-3465 ◽  
Author(s):  
André Nantel ◽  
Daniel Dignard ◽  
Catherine Bachewich ◽  
Doreen Harcus ◽  
Anne Marcil ◽  
...  
Keyword(s):  
Time Course ◽  
Dna Microarrays ◽  
Culture Medium ◽  
Developmental Process ◽  
Pathogenic Fungus ◽  
Hyphal Growth ◽  
Transcription Profiles ◽  
Hyphal Morphology ◽  
External Signals ◽  
Temperature Time

The ability of the pathogenic fungus Candida albicans to switch from a yeast to a hyphal morphology in response to external signals is implicated in its pathogenicity. We used glass DNA microarrays to investigate the transcription profiles of 6333 predicted ORFs in cells undergoing this transition and their responses to changes in temperature and culture medium. We have identified several genes whose transcriptional profiles are similar to those of known virulence factors that are modulated by the switch to hyphal growth caused by addition of serum and a 37°C growth temperature. Time course analysis of this transition identified transcripts that are induced before germ tube initiation and shut off later in the developmental process. A strain deleted for the Efg1p and Cph1p transcription factors is defective in hyphae formation, and its response to serum and increased temperature is almost identical to the response of a wild-type strain grown at 37°C in the absence of serum. Thus Efg1p and Cph1p are needed for the activation of the transcriptional program that is induced by the presence of serum.

scholarly journals Investigation of Botrytis Cinerea Risk Forecasting Model of Strawberry in Lithuania

2013 ◽  
Vol 67 (2) ◽  
pp. 195-198 ◽  
Author(s):  
Neringa Rasiukevičiūtė ◽  
Alma Valiuškaitė ◽  
Elena Survilienė-Radzevičė ◽  
Skaidrė Supronienė
Keyword(s):  
Disease Management ◽  
Botrytis Cinerea ◽  
Air Temperature ◽  
Grey Mould ◽  
Management Systems ◽  
Forecasting Model ◽  
Leaf Wetness ◽  
Risk Of Infection ◽  
Risk Forecasting ◽  
Risk Probability

Grey mould, caused by Botrytis cinerea Pers.:Fr. is one of the most important strawberry diseases in Lithuania, like in other countries, where strawberries are grown. The efficiency of different disease management systems were analyzed at the Institute of Horticulture in 2010-2011. The B. cinerea risk probability at various regions of Lithuania was analyzed according to iMETOS ®sm grey mould risk forecasting model. Strawberry grey mould risk forecasting model indicates the risk of infection periods on the basis of the interaction between air temperature and leaf wetness duration. The model calculates how favourable is the period for the risk of infection. In periods where the risk is consistent (more than three days), higher than 60 points, a spray against grey mould should be applied. iMETOS®sm grey mould risk forecasting model gives the opportunity to optimize the usage of fungicides and reduce the number of applications and allows more efficient, ecologically and economically accepted control of strawberries grey mould.

scholarly journals Stimulatory Effects of Sublethal Doses of Dimethachlon on Sclerotinia sclerotiorum

Plant Disease ◽  
2014 ◽  
Vol 98 (10) ◽  
pp. 1364-1370 ◽  
Author(s):  
Feng Zhou ◽  
Hong-Jie Liang ◽  
Ya-Li Di ◽  
Hong You ◽  
Fu-Xing Zhu
Keyword(s):  
Oilseed Rape ◽  
Sclerotinia Sclerotiorum ◽  
Mycelial Growth ◽  
Plant Disease ◽  
Pathogenic Fungi ◽  
Potato Dextrose Agar ◽  
Detached Leaves ◽  
Sublethal Doses ◽  
Fungal Phytopathogens ◽  
Plant Disease Management

Growth and virulence stimulations of sublethal doses of fungicides on plant-pathogenic fungi and oomycetes have been reported and the stimulatory effects are potentially relevant to plant disease management. Sclerotinia sclerotiorum is one of the most devastating and economically important necrotrophic fungal phytopathogens, capable of infecting more than 400 species of plants worldwide. In order to study stimulatory effects of sublethal doses of fungicides on S. sclerotiorum, 55 dimethachlon-sensitive isolates and 3 dimethachlon-resistant isolates of S. sclerotiorum were assayed to determine effects of sublethal doses of dimethachlon on mycelial growth rate on potato dextrose agar (PDA) media and virulence on oilseed rape plants. Results showed that all 3 dimethachlon-resistant isolates and 13 of the 55 sensitive isolates exhibited stimulatory responses to sublethal doses of dimethachlon. Dimethachlon-resistant isolates grew significantly (P < 0.05) faster on PDA media amended with dimethachlon at 0.5 to 4 μg/ml than on fungicide-free PDA media. As for virulence on detached leaves of oilseed rape plants, lesion diameters of dimethachlon-resistant isolates after growth on PDA media amended with dimethachlon at 0.5 to 2 μg/ml were significantly larger (P < 0.05) than the control. The maximum stimulatory effects were 42.40 to 59.80%. In pot experiments, for both dimethachlon-sensitive and -resistant isolates, significant (P < 0.05) virulence stimulations were observed after spraying with dimethachlon at a concentration of 2 μg/ml. After growing on dimethachlon-amended PDA media, H2O2 sensitivity of S. sclerotiorum decreased significantly (P < 0.05) compared with the nonamended PDA control.

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