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1.
Phytopathology ; 112(5): 1165-1174, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35365059

RESUMO

Mycotoxin contamination is a leading cause of food spoilage and waste on a global scale. Patulin, a mycotoxin produced by Penicillium spp. during postharvest pome fruit decay, causes acute and chronic effects in humans, withstands pasteurization, and is not eliminated by fermentation. While much is known about the impact of patulin on human health, there are significant knowledge gaps concerning the effect of patulin during postharvest fruit-pathogen interactions. Application of patulin on six apple cultivars reproduced some blue mold symptoms that were cultivar-independent and dose-dependent. Identical symptoms were also observed in pear and mandarin orange. Six Penicillium isolates exposed to exogenous patulin exhibited delayed germination after 24 h, yet all produced viable colonies in 7 days. However, four common postharvest phytopathogenic fungi were completely inhibited by patulin during conidial germination and growth, suggesting the toxin is important for Penicillium to dominate the postharvest niche. Using clorgyline, a broad-spectrum efflux pump inhibitor, we demonstrated that efflux plays a role in Penicillium auto-resistance to patulin during conidial germination. The work presented here contributes new knowledge of patulin auto-resistance, its mode of action, and inhibitory role in fungal-fungal interactions. Our findings provide a solid foundation to develop toxin and decay mitigation approaches.


Assuntos
Malus , Patulina , Penicillium , Frutas/microbiologia , Malus/microbiologia , Patulina/análise , Patulina/farmacologia , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Virulência
2.
J Nanobiotechnology ; 20(1): 182, 2022 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-35392922

RESUMO

BACKGROUND: Citrus production and trading are seriously affected by fungal decays worldwide; the green mold infection by Penicillium digitatum could be the most disastrous. The substitutions of chemical and synthetic fungicides with effectual natural alternatives are global demands; plant extract from pomegranates peels (PPE), biosynthesized selenium nanoparticles with PPE (PPE/SeNPs) and chitosan nanoparticles (NCT) were suggested as efficacious fungicidal agents/nanocomposites to control P. digitatum strains. METHOD: PPE from Punica granatum was extracted and employed directly for synthesizing SeNPs, whereas NCT was produced using ionic gelation method of chitosan extracted from white prawn (Fenneropenaeus indicus) shells. The physiochemical, biochemical and structural characterization of generated molecules were conducted using infra-red spectroscopy, particles' size (Ps) and charge assessment and electron microscopes imaging. Antifungal potentialities were investigated in vitro and in infected fruits with P. digitatum by applying NCT nanocomposites-based edible coating. RESULTS: The synthesis of PPE-synthesized SeNPs and NCT was successfully achieved, the molecular bonding in synthesized agents/composites were proved with infrared spectroscopy to have both biochemical and physical interactions. The nanoparticles had 82.72, 9.41 and 85.17 nm mean diameters for NCT, PPE/SeNPs and NCT/PPE/SeNPs nanocomposites, respectively. The nanoparticles had homogenous spherical shapes and good distribution attributes. The entire agents/nanocomposites exhibited potent fungicidal potentialities toward P. digitatum isolates; NCT/PPE/SeNPs nanocomposite was the most forceful and significantly exceeded the fungicidal action of standard fungicide. The direct treatment of fungal mycelia with NCT/PPE/SeNPs nanocomposite led to remarkable lysis and deformations of P. digitatum hyphae within 12 h of treatment. The coating of infected orange with NCT-based edible coatings reduced the green mold infection signs by 91.7, 95.4 and 100%, for NCT, NCT/PPE and NCT/PPE/SeNPs based coating solutions, respectively. CONCLUSIONS: NCT, PPE-synthesized SeNPs, and their innovative nanocomposites NCT/PPE/SeNPs are convincingly recommended for formulating effectual antifungal and edible coatings to eliminate postharvest fungal pathogen, both with protection from their invasion or with destructing their existing infections.


Assuntos
Quitosana , Citrus , Filmes Comestíveis , Fungicidas Industriais , Nanopartículas , Romã (Fruta) , Selênio , Antifúngicos/farmacologia , Quitosana/química , Frutas/química , Frutas/microbiologia , Fungicidas Industriais/análise , Fungicidas Industriais/farmacologia , Selênio/farmacologia
3.
J Agric Food Chem ; 70(13): 3948-3957, 2022 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-35324179

RESUMO

Hexaconazole (HEZ) is a triazole fungicide registered to prevent and control grey mold disease on tomatoes. Many triazole fungicides exhibit plant regulator functions. Therefore, it is necessary to understand the effects of HEZ fungicides on the growth and development of tomatoes. In the present study, the effect of HEZ on healthy and Botrytis cinerea (B. cinerea)-infected tomato plants was investigated. We found that HEZ delayed fruit ripening when applied to healthy tomato plants and further changed the taste and flavor of these fruit. HEZ increased the size and prevented the rotting of the tomato fruit, thus saving grey mold infection-related losses. Moreover, compared with applying HEZ on healthy plants, the application of HEZ on B. cinerea-infected plants increased the metabolism of sugars, acids, and aromatic compounds in these fruit. Therefore, HEZ can effectively control fungal pathogens but reduce the quality of tomato fruit.


Assuntos
Fungicidas Industriais , Lycopersicon esculentum , Botrytis , Frutas/microbiologia , Fungicidas Industriais/metabolismo , Fungicidas Industriais/farmacologia , Lycopersicon esculentum/microbiologia , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Triazóis/metabolismo , Triazóis/farmacologia
4.
Wei Sheng Yan Jiu ; 51(1): 63-67, 2022 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-35341496

RESUMO

OBJECTIVE: To investigate the microbial contamination in dried fruit products in China. METHODS: In 2019, 2917 samples of dried fruit products on the market were collected, and examined for aerobic bacterial count, coliforms, molds, yeasts, Salmonella and Listeria monocytogenes according to the method specified in GB 4789. RESULTS: A total of 34.42%(1004/2917)of the samples had molds above 50 CFU/g and 9.46%(276/2917)of the samples had yeast above 50 CFU/g. The occurrence of aerobic plate count above 10~4 CFU/g and coliforms above 10~2 CFU/g was 5.01%(146/2917)and 2.98%(87/2917), respectively. The detection rate of Salmonella and Listeria monocytogenes were 0.14%(4/2917) and 0.03%(1/2917), respectively. Microbial contamination in different kinds of dried fruit products varied widely, with dried wolfberries and dried durian having the worst overall hygiene. There were differences in microbial contamination of dried fruit products in different regions. In general, samples collected in South China, Southwest China and Central China had more serious microbial contamination. There was no significant difference in microbial contamination between dried fruit products with different packaging and sampling places. CONCLUSION: The hygienic condition of dried fruit products is generally poor in 2019.


Assuntos
Frutas , Listeria monocytogenes , Contagem de Colônia Microbiana , Microbiologia de Alimentos , Frutas/microbiologia , Salmonella
5.
Fungal Biol ; 126(4): 277-289, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35314059

RESUMO

Alternaria rot has been recently described as an emerging fungal disease of citrus causing significant damage in California groves. A survey was conducted to determine latent infections on fruits, twigs, and leaves and investigate their seasonal patterns during 2019 and 2020. On fruits, latent infections were more associated with the stem end than with the stylar end, except during spring when a significantly high percentage of flowers (86%) had latent infections. Latent infections on twigs varied markedly between years (28% in 2019 and 9.5% in 2020), while Alternaria spp. were also recovered from citrus leaves. Alternaria isolates collected during the survey were identified based on multigene sequence analysis, confirming that Alternaria alternata and Alternaria arborescens are the two species associated with infections of citrus fruits. Of the 23 isolates, 19 were identified as A. alternata and demonstrated the dominance of this species over A. arborescens. Isolates representing populations of these two species were selected as representative isolates for physiological and morphological studies. A. alternata and A. arborescens showed similar conidial dimensions but differed in the number of conidia produced. Growth rates demonstrated that A. alternata grows faster than A. arborescens at all the temperatures evaluated, except at 25 and 35 °C. The growth patterns were similar for both species. The sporulation rate of the Alternaria isolates was influenced differently by temperature. This parameter also influenced conidial germination and appressorium formation, and no significant differences were observed between Alternaria species. Pathogenicity and aggressiveness tests on detached fruit demonstrated the ability of A. alternata and A. arborescens to cause internal lesions and produce fruit drop in the orchards with no quantitative differences between them (disease severity indexes of 58 and 68%, respectively). The fungicide sensitivity tests showed that DMI fungicides are the most effective fungicides in reducing mycelial growth. The SDHI fungicides had intermediate activity against the mycelial growth but also suppressed spore germination. The spore germination assay suggested that some of the isolates included in this study might have some level of resistance to QoI and SDHI fungicides. The findings of this study provide new information about the pathogens associated with the excessive fruit drop recently observed in some California citrus groves.


Assuntos
Citrus , Fungicidas Industriais , Alternaria , Citrus/microbiologia , Frutas/microbiologia , Fungicidas Industriais/farmacologia , Esporos Fúngicos , Virulência
6.
PLoS One ; 17(3): e0265457, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35294498

RESUMO

ε-Poly-l-lysine (ε-PL) is a natural antimicrobial polymer with significant inhibitory activity against a broad spectrum of microorganisms, and nowadays used widely as a preservative in the food industry. In the present study, ε-PL broth was obtained from Streptomyces ahygroscopicus GIM8 fermentation in a nutrient-limited liquid medium. The in vitro antifungal activity of the broth against fruit pathogens Penicillium expansum and Colletotrichum gloeosporioides was investigated, and its usage for postharvest storage of two highly perishable fruits wax apple and guava was evaluated. Results showed that ε-PL concentration in the broth reached 0.61 g/L, and the nutrition level of the broth was low. The antifungal activity of ε-PL broth was comparable to that of the aqueous solution of ε-PL under the same concentration. Immersion with the diluted broth (200 mg/L ε-PL) markedly delayed the decline in the quality of postharvest wax apple and guava fruits during storage, and the decay incidences were also greatly decreased as compared to their respective controls (distilled water immersion). A further investigation demonstrated that the ε-PL broth immersion induced an increase in the activity of defense-related enzymes peroxidase and polyphenol oxidase in the two fruits during storage. The present study proved that the fermentation broth of ε-PL could be used as a promising alternative to high purity ε-PL and synthetic fungicides for preserving fruits at postharvest stage.


Assuntos
Psidium , Streptomyces , Syzygium , Antifúngicos/farmacologia , Frutas/microbiologia , Polilisina/farmacologia
7.
Sci Rep ; 12(1): 4340, 2022 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-35288581

RESUMO

In recent times, the application of protein-based bio-composite edible films in postharvest preservation of food and agricultural products is attracting increased attention due to their biodegradability, eco-friendliness and sustainability. In this study, an avocado pear peel polyphenolic extract enriched keratin-starch composite film was fabricated, characterized and evaluated for antimicrobial activity against fungal infected tomato fruits after 6 days of storage at room (25 ± 2 °C) temperature. The SEM/EDX and FTIR results revealed the successful film formation with high degree of compatibility and homogeneity. Following a 6-day post-coating loss in weight of the coated tomato fruits decreased significantly (p < 0.05) with increasing extract concentration while titratable acidity showed a significant (p < 0.05) increase with increasing extract load. Ascorbic acid and lycopene contents were significantly (p < 0.05) higher in the avocado pear peel polyphenolic extract-loaded films. No significant effect was observed in catechol oxidase activity of the tomato extract across the different treatment groups. In addition, fungal growth inhibition showed a dose dependent increase consistent with avocado pear peel polyphenolic load in coated tomato fruits compared to control. Results obtained in this study showed that polyphenolic activated keratin-starch coating was able to reduce spoilage-induce weight loss as well as conserve the overall quality (including titratable acid levels, lycopene and ascorbic acid contents) of fungal-infected tomato fruit and reduce microbial growth. Therefore polyphenolic activated keratin-starch coating could serve as a sustainable and ecofriendly postharvest preservation method to prolong the shelf life of tomato fruits.


Assuntos
Frutas , Lycopersicon esculentum , Antifúngicos/farmacologia , Ácido Ascórbico/farmacologia , Frutas/microbiologia , Queratinas , Licopeno/farmacologia , Amido/farmacologia
9.
PLoS One ; 17(2): e0264543, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35213640

RESUMO

Bacterial spot, caused by Xanthomonas arboricola pv. pruni (Xap), is a serious peach disease with symptoms that traverse severe defoliation and black surface pitting, cracking or blemishes on peach fruit with global economic impacts. A management option for control and meeting consumer demand for chemical-free, environmentally friendly fruit production is the development of resistant or tolerant cultivars. We developed simple, accurate, and efficient DNA assays (Ppe.XapF) based on SNP genotyping with KASP technology to quickly test for bacterial spot resistance alleles in peach fruit that allows breeders to cull seedlings at the greenhouse stage. The objective of this research was to validate newly developed DNA tests that target the two major QTLs for fruit resistance in peach with diagnostic utility in predicting fruit response to bacterial spot infection. Our study confirms that with only two Ppe.XapF DNA tests, Ppe.XapF1-1 and Ppe.XapF6-2, individuals carrying susceptible alleles can be identified. Use of these efficient and accurate Ppe.XapF KASP tests resulted in 44% reduction in seedling planting rate in the Clemson University peach breeding program.


Assuntos
Técnicas de Genotipagem/métodos , Doenças das Plantas/microbiologia , Prunus persica/genética , Xanthomonas/genética , Alelos , DNA Bacteriano/análise , DNA Bacteriano/genética , Resistência à Doença/genética , Frutas/genética , Frutas/metabolismo , Frutas/microbiologia , Ensaios de Triagem em Larga Escala , Doenças das Plantas/genética , Polimorfismo de Nucleotídeo Único , Prunus persica/crescimento & desenvolvimento , Prunus persica/metabolismo , Prunus persica/microbiologia , Locos de Características Quantitativas , Xanthomonas/isolamento & purificação
10.
Food Chem ; 381: 132197, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35121319

RESUMO

Colletotrichum asianum (C. asianum) is a new pathogenic fungus that causes mango anthracnose. Cold plasma is a novel non-thermal decontamination technology, which has been proven to be effective in controlling postharvest fungus. Herein, dielectric barrier discharge (DBD) plasma was used to treat C. asianum spores in sterile phosphate-buffered saline, the damages in subcellular structures of C. asianum and inhibition of mango anthracnose were evaluated. Results showed that after 9 min treatment, the spore germination rate and spore viability were decreased by 95.48% and 98.82%, respectively, and the subcellular structures were damaged (P < 0.05), leading to spores death. Besides, DBD plasma treatments could control mango anthracnose and maintain mango quality, and the disease incidence and lesion diameter of mango treated for 9 min were decreased by 48.00% and 62.95%, respectively. Therefore DBD plasma inactivated C. asianum spore, providing an alternative technique for preventing and controlling mango anthracnose.


Assuntos
Colletotrichum , Mangifera , Frutas/microbiologia , Mangifera/microbiologia , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle
11.
Int J Food Microbiol ; 366: 109561, 2022 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-35139442

RESUMO

Anthracnose decay is one of the major causes of postharvest losses of avocados (Persea americana), during marketing. Currently, Prochloraz® fungicide is used to control anthracnose at postharvest stage which poses threat to consumer safety. Therefore, this study evaluated the effects of high and low molecular weight chitosan on the control of avocado anthracnose and fruit defence mechanism. In curative inoculation, avocados '(Fuerte') were inoculated via the wounds with C. gloeosporioides spore suspension (20 µL, 1 × 106 spores mL-1). Thereafter coated with different concentrations (0.5%, 1% and 1.5%) of low (LMWC) and high molecular weight (HMWC) chitosan and fruits were held at 25 °C for 5 days. The % anthracnose incidence in avocado fruits was recorded on day 5. During preventative inoculation, wounded fruits were dipped in different concentrations of LMWC or HMWC solutions, and subsequently inoculated with C. gloeosporioides suspension. Preventatively inoculated fruits were stored for 28 days at 6.5 °C, 85% RH and thereafter for 5 days at 25 °C and 75% RH to simulated market shelf condition. The % anthracnose incidence was recorded on day 5. Fruit treated with Prochloraz® and water were included as controls for both curative and preventative infected fruits. Promising chitosan coatings with the lowest anthracnose incidence and the controls were investigated for skin epicatechin content, defence-related genes; phenylalanine ammonia lyase (PAL), lipoxygenase (LOX), fatty acid elongase (avael) and desaturase (avfad 12-3), chalcone synthase (CHS) and flavonol synthase (FLS) using RT- qPCR method. The zeta potential of selected chitosan coatings was done following standard procedures. Percentage of anthracnose incidence were lowest in 1.5% LMWC (18%, 3 mm) compared to Prochloraz® (23%, 5 mm) and the untreated fruit (90%, 24 mm). The 1.5% LMWC had the highest up-regulation of PAL, avfael, avfad 12-3, CHS, FLS genes and down-regulation of LOX gene with concomitant increase in epicatechin content (340 mg kg-1) relative to other chitosan treatments, untreated and Prochloraz® treated fruits. The superior positive zeta potential of LMWC 1.5% coating corroborates its effectiveness in controlling avocado anthracnose than HMWC 1.5%. It is possible that the interaction between the positively charged chitosan amino group (-NH3+) and the negatively charged microbial cell membrane is responsible for the enhanced antifungal activity. In late season naturally infected fruits dipped in 1.5% LMWC, anthracnose incidence dropped to 28% while Prochloraz® treated fruits showed anthracnose incidence of 82% on day 8 at the market shelf. LMWC 1.5% can replace the currently used Prochloraz®.


Assuntos
Quitosana , Persea , Quitosana/farmacologia , Frutas/microbiologia , Incidência , Peso Molecular , Persea/microbiologia
12.
Viruses ; 14(2)2022 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-35215777

RESUMO

Ralstonia solanacearum is a pathogen that causes bacterial wilt producing severe damage in staple solanaceous crops. Traditional control has low efficacy and/or environmental impact. Recently, the bases of a new biotechnological method by lytic bacteriophages vRsoP-WF2, vRsoP-WM2 and vRsoP-WR2 with specific activity against R. solanacearum were established. However, some aspects remain unknown, such as the survival and maintenance of the lytic activity after submission to a preservation method as the lyophilization. To this end, viability and stability of lyophilized vRsoP-WF2, vRsoP-WM2 and vRsoP-WR2 and their capacity for bacterial wilt biocontrol have been determined against one pathogenic Spanish reference strain of R. solanacearum in susceptible tomato plants in different conditions and making use of various cryoprotectants. The assays carried out have shown satisfactory results with respect to the viability and stability of the bacteriophages after the lyophilization process, maintaining high titers throughout the experimental period, and with respect to the capacity of the bacteriophages for the biological control of bacterial wilt, controlling this disease in more than 50% of the plants. The results offer good prospects for the use of lyophilization as a conservation method for the lytic bacteriophages of R. solanacearum in view of their commercialization as biocontrol agents.


Assuntos
Bacteriófagos/química , Bacteriófagos/crescimento & desenvolvimento , Agentes de Controle Biológico/química , Conservação de Alimentos/métodos , Lycopersicon esculentum/microbiologia , Doenças das Plantas/prevenção & controle , Ralstonia solanacearum/virologia , Conservação de Alimentos/economia , Liofilização , Frutas/economia , Frutas/microbiologia , Lycopersicon esculentum/economia , Doenças das Plantas/microbiologia , Ralstonia solanacearum/fisiologia
13.
BMC Microbiol ; 22(1): 44, 2022 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-35120460

RESUMO

BACKGROUND: Pseudomonas savastanoi is an important plant pathogen that infects and causes symptoms in a variety of economically important crops, causing considerable loss of yield and quality. Because there has been no research reported to date on bacterial canker of kiwifruit (Actinidia chinensis) plants caused by P. savastanoi and, in particular, no in-depth studies of the complete genome sequence or pathogenic mechanism, long-lasting and environmentally friendly control measures against this pathogen in kiwifruit are lacking. This study therefore has both theoretical value and practical significance. RESULTS: We report the complete genome sequence of P. savastanoi strain MHT1, which was first reported as the pathogen causing bacterial canker in kiwifruit plants. The genome consists of a 6.00-Mb chromosome with 58.5% GC content and 5008 predicted genes. Comparative genome analysis of four sequenced genomes of representative P. savastanoi strains revealed that 230 genes are unique to the MHT1 strain and that these genes are enriched in antibiotic metabolic processes and metabolic pathways, which may be associated with the drug resistance and host range observed in this strain. MHT1 showed high syntenic relationships with different P. savastanoi strains. Furthermore, MHT1 has eight conserved effectors that are highly homologous to effectors from P. syringae, Pseudomonas amygdali, and Ralstonia solanacearum strains. The MHT1 genome contains six genomic islands and two prophage sequences. In addition, 380 genes were annotated as antibiotic resistance genes and another 734 as encoding carbohydrate-active enzymes. CONCLUSION: The whole-genome sequence of this kiwifruit bacterial canker pathogen extends our knowledge of the P. savastanoi genome, sets the stage for further studies of the interaction between kiwifruit and P. savastanoi, and provides an important theoretical foundation for the prevention and control of bacterial canker.


Assuntos
Actinidia/microbiologia , Frutas/microbiologia , Genoma Bacteriano , Doenças das Plantas/microbiologia , Pseudomonas/genética , Composição de Bases , Produtos Agrícolas/genética , Produtos Agrícolas/microbiologia , Ilhas Genômicas , Pseudomonas/patogenicidade , Virulência/genética
14.
Plant Dis ; 106(2): 745-747, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35130035

RESUMO

Nigrospora sphaerica is a worldwide plant pathogen causing fruit or leaf diseases on a variety of plant hosts such as Citrullus lanatus, Vigna unguiculata, Hylocereus polyrhizus, and Akebia trifoliata and other potential hosts. Here we report the first genome resource with high-quality assembly of the N. sphaerica strain ZJJ-C1, which causes fruit dried-shrink disease in A. trifoliata in China. The genome sequence of ZJJ-C1 will be useful for studying the evolution, host adaptation, and pathogenicity of N. sphaerica, which will be beneficial for a better understanding of the mechanisms of host-pathogen interaction during the endophytic period.


Assuntos
Ascomicetos , Frutas , Genoma Fúngico , Doenças das Plantas/microbiologia , Ranunculales/microbiologia , Ascomicetos/genética , Frutas/microbiologia , Interações Hospedeiro-Patógeno , Folhas de Planta
15.
Fungal Biol ; 126(3): 201-212, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35183337

RESUMO

Blue mold caused by Penicillium italicum is a severe postharvest disease in citrus fruits. In this study, the fermentation product (FP-E) of Aspergillus aculeatus GC-09, an endophytic fungus isolated from a citrus plant, was found to exhibit antifungal activity against P. italicum with a MIC of 0.3125 mg/mL. The fungus A. aculeatus GC-09 was identified based on the studies of morphology and ITS nucleotide sequence. FP-E significantly inhibited the spore germination and mycelial growth of P. italicum. Scanning electron microscopy (SEM) results of P. italicum treated with FP-E showed shrunken, distorted and collapsed hyphae and conidiospores, indicative of the cell membrane damage, which was further confirmed by the propidium iodide (PI) fluorescent staining analysis. Consistent with the microscopy observation, FP-E led to the leakage of cellular constituents from P. italicum, which is evident from the increase in electrical conductivity and nucleic acid contents in the mycelial solution incubated with FP-E. In addition, FP-E treatment considerably increased the intracellular reactive oxygen species (ROS) content, and reduced the enzyme activities of both catalase (CAT) and peroxidase (POD) in P. italicum cells. Furthermore, orange fruits treated with FP-E showed fewer disease symptoms compared to the untreated fruits. These results suggested that the antifungal activity of FP-E might be associated with the disruption of cell membrane integrity, the accumulation of ROS level, and the reduction of the antioxidant enzymes activity of P. italicum. Therefore, A. aculeatus GC-09 might be a potential microbial resource for the biocontrol of citrus postharvest blue mold.


Assuntos
Citrus , Penicillium , Aspergillus , Citrus/microbiologia , Frutas/microbiologia , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle
16.
Fitoterapia ; 156: 105070, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34718093

RESUMO

Kiwi (Actinidia chinensis) plants are severely destroyed by canker disease which is caused by the bacterium Pseudomonas syringae pv. actinidiae (Psa). This program tries to find anti-Psa agents among secondary metabolites of endophytic fungi from kiwi plant itself. The chemical investigation on one kiwi endophytic fungi, Fusarium tricinctum, resulted in the isolation of nine new imidazole alkaloids, fusaritricines A-I (1-9) together with seven known analogues (10-16). The structures of new compounds were established by extensive spectroscopic methods. Compounds 2, 3, 9, and 13 showed good antibacterial activity against Psa with MIC values between 25 and 50 µg/mL. It is suggested that imidazole alkaloids should be potential anti-Psa agents.


Assuntos
Actinidia/microbiologia , Alcaloides/farmacologia , Antibacterianos/farmacologia , Fusarium/química , Imidazóis/farmacologia , Pseudomonas syringae/efeitos dos fármacos , Alcaloides/química , Alcaloides/isolamento & purificação , Antibacterianos/síntese química , Antibacterianos/isolamento & purificação , Análise de Fourier , Frutas/microbiologia , Imidazóis/química , Imidazóis/isolamento & purificação , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Pseudomonas syringae/isolamento & purificação , Espectrofotometria Infravermelho , Espectrofotometria Ultravioleta
17.
Plant Dis ; 106(2): 451-463, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34597150

RESUMO

Bull's eye rot, caused by Phlyctema vagabunda and Neofabraea species, is one of the most important postharvest diseases of apple. South Tyrol (northern Italy) is the largest continuous apple-producing area in Europe, with approximately 1 million tons being produced yearly and conserved in technologically advanced storage facilities for several months. Still, studies on the pathogen species causing postharvest bull's eye rot of apple, as well as their diversity and biology, are lacking for this region. Therefore, the main purpose of the present work was to identify and characterize fungal isolates obtained from decayed apple fruit with symptoms of bull's eye rot that were collected in 2018 and 2019 in different packinghouses in South Tyrol. Among more than 1,000 fungal isolates that were obtained, 419 could be assigned to the genera Phlyctema and/or Neofabraea based on rot symptoms on apple fruit and colony morphology on potato dextrose agar. A smaller subset of 101 representative isolates was further analyzed by DNA sequencing of the internal transcribed spacer region. Furthermore, partial segments of the ß-tubulin gene, the translation elongation factor 1α gene, and the 16S mitochondrial ribosomal RNA gene were studied. The phylogenetic analyses, including sequences of reference species, showed that P. vagabunda is the dominant species associated with bull's eye rot of apple in the study area, whereas Neofabraea kienholzii was found only on a small number of apple fruit samples. The combination of multilocus sequence data revealed 11 unique genotypes that belonged to P. vagabunda and four to N. kienholzii. To the best of our knowledge, this study is the first to report N. kienholzii as a postharvest pathogen of apple in Italy. Finally, a pathogenicity test demonstrated different degrees of virulence among selected isolates of P. vagabunda and N. kienholzii on the cultivar Golden Delicious. The present study emphasizes the importance of accurate species identification, because different species may vary in their biological and pathogenic characteristics, and consequently require distinct disease management strategies, both in the field and during the postharvest stages.[Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.


Assuntos
Malus , Ascomicetos , Frutas/microbiologia , Malus/microbiologia , Filogenia
18.
J Sci Food Agric ; 102(3): 1245-1254, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34378222

RESUMO

BACKGROUND: Phytopathogenic microorganisms are the main cause of plant diseases, generating significant economic losses for the agricultural and food supply chain. Cherry tomatoes (Solanum lycopersicum var. cerasiforme) are very perishable plants and highly demanding in the use of pesticides; therefore, alternative solutions such as biosurfactants have aroused as a potent substituent. The main objective of the present study was to investigate the antimicrobial activity of sophorolipids against the phytopathogens Botrytis cinerea, Sclerotium rolfsii, Rhizoctonia solani and Pythium ultimum. RESULTS: The biosurfactant inhibited the mycelial growth in vitro with a minimum concentration of 2 mg mL-1 . The application of sophorolipids at 1, 2 and 4 mg mL-1 in detached leaves of tomato before the inoculation of the fungus B. cinerea was the best treatment, reducing leaf necrosis by up to 76.90%. The use of sophorolipids for washing tomato fruits before the inoculation of B. cinerea was able to inhibit the development of gray mold by up to 96.27%. CONCLUSION: The results for tomato leaves and fruits revealed that the biosurfactant acts more effectively when used preventively. Sophorolipids are stable molecules that show promising action for the potential replacement of pesticides in the field and the post-harvest process against the main tomato phytopathogens. © 2021 Society of Chemical Industry.


Assuntos
Botrytis/efeitos dos fármacos , Fungicidas Industriais/farmacologia , Lycopersicon esculentum/microbiologia , Ácidos Oleicos/farmacologia , Doenças das Plantas/microbiologia , Rhizoctonia/efeitos dos fármacos , Saccharomycetales/metabolismo , Botrytis/fisiologia , Frutas/microbiologia , Fungicidas Industriais/metabolismo , Ácidos Oleicos/metabolismo , Doenças das Plantas/prevenção & controle , Folhas de Planta/microbiologia , Rhizoctonia/fisiologia , Saccharomycetales/química
19.
J Toxicol Environ Health A ; 85(2): 43-55, 2022 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-34459359

RESUMO

Monilinia fructicola (Wint.) Honey is a plant pathogenic fungus that infects stone fruits such as peach, nectarine and plum, which are high demand cultivars found in Brazil. This pathogen may remain latent in the host, showing no apparent signs of disease, and consequently may spread to different countries. The aim of this study was to evaluate the activity of hydroalcoholic extract (HydE) obtained from Lactarius deliciosus (L.) Sf. Gray a mushroom, against M. fructicola phytopathogenic-induced mycelial growth. In addition, the purpose of this study was to examine phytotoxicity attributed to HydE using Brassica oleracea seeds, as well as cytotoxic analysis of this extract on cells of mouse BALB/c monocyte macrophage cell line (J774A.1 cell line) (ATCC TIB-67). The L. deliciosus HydE inhibited fungal growth and reduced phytopathogen mycelial development at a concentration of 1.25 mg/ml. Our results demonstrated that the extract exhibited phytotoxicity as evidenced by (1) interference on germination percentage and rate index, (2) decreased root and initial growth measures, and (3) lower fresh weight of seedlings but no cytotoxicity in Vero cell lines. Data suggest that the use of the L. deliciosus extracts may be beneficial for fungal control without any apparent adverse actions on mouse BALB/c monocyte macrophage cell line (J774A.1 cell line) viability.


Assuntos
Antifúngicos/farmacologia , Basidiomycota/química , Agentes de Controle Biológico/farmacologia , Animais , Antifúngicos/química , Ascomicetos/efeitos dos fármacos , Ascomicetos/crescimento & desenvolvimento , Agentes de Controle Biológico/química , Brasil , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/farmacologia , Frutas/microbiologia , Germinação/efeitos dos fármacos , Camundongos , Micélio/efeitos dos fármacos , Micélio/crescimento & desenvolvimento , Fenol/análise , Doenças das Plantas/microbiologia , Sementes/crescimento & desenvolvimento , Sementes/microbiologia
20.
J Sci Food Agric ; 102(3): 898-907, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34240436

RESUMO

BACKGROUND: Filamentous fungi are the main contamination agent in the viticultural sector. Use of synthetic fungicides is the regular answer to these contaminations. Nevertheless, because of several problems associated with the use of synthetic compounds, the industry demands new and safer methods. In the present work, the biopreservation potential of four lactic acid bacteria (LAB) strains was studied against the principal grape contaminant fungi. RESULTS: Agar diffusion test evidenced that all four culture-free supernatant (CFS) had antifungal properties against all tested fungi. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) test values evidenced that media fermented by the Lactobacillus plantarum E3 and Lactobacillus plantarum E4 strains showed the highest antifungal activity, resulting in an MFC from 6.3 to 100 g L-1 . Analysis of CFS evidenced the presence of different antifungal compounds, such as lactic acid, phenyllactic acid and pyrazines. In tests on red grapes, an average reduction of 1.32 log10 of the spores per gram of fruit was achieved by all CFS in grapes inoculated with Aspergillus ochraceus and by 0.94 log10 for L. plantarum E3 CFS against Botrytis cinerea. CONCLUSION: The antifungal activity of the fermented CFS by L. plantarum E3 reduced the growth of B. cinerea and A. ochraceus in grapes, which are the main contaminant and main producer of ochratoxin A in these crops, respectively. Therefore, based on the results obtained in this work, use of the strain L. plantarum E3 could be an interesting option for the biopreservation of grapes. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Assuntos
Conservação de Alimentos/métodos , Fungos/efeitos dos fármacos , Fungicidas Industriais/farmacologia , Lactobacillus plantarum/química , Vitis/microbiologia , Contaminação de Alimentos/prevenção & controle , Frutas/microbiologia , Fungos/crescimento & desenvolvimento , Fungicidas Industriais/análise , Fungicidas Industriais/metabolismo , Lactatos/análise , Lactatos/metabolismo , Lactatos/farmacologia , Ácido Láctico/análise , Ácido Láctico/metabolismo , Ácido Láctico/farmacologia , Lactobacillus plantarum/metabolismo , Pirazinas/análise , Pirazinas/metabolismo , Pirazinas/farmacologia
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