AVIRULENCE IN PROTOTROPHS OF PENICILLIUM EXPANSUM

1966 ◽  
Vol 44 (3) ◽  
pp. 355-358 ◽  
Author(s):  
B. H. MacNeill ◽  
G. L. Barron
Keyword(s):  
Penicillium Expansum ◽  
Wild Type ◽  
Apple Fruits

Over 100,000 prototrophic survivors from ultraviolet-irradiated stock were screened for pathogenicity on apple fruits. Of these, seven showed altered pathogenic capacity when compared with the wild type, five having reduced virulence and two being completely avirulent. The nutritional hypothesis of pathogenicity, as presently conceived, seems inadequate to explain the observed changes in virulence. It is suggested that, in the complex association of host and pathogen, the mechanism controlling pathogenicity must be considered as distinct from that which governs the basic metabolism of the parasite.

scholarly journals A Novel Secreted Cysteine-Rich Anionic (Sca) Protein from the Citrus Postharvest Pathogen Penicillium digitatum Enhances Virulence and Modulates the Activity of the Antifungal Protein B (AfpB)

2020 ◽  
Vol 6 (4) ◽  
pp. 203
Author(s):  
Sandra Garrigues ◽  
Jose F. Marcos ◽  
Paloma Manzanares ◽  
Mónica Gandía
Keyword(s):  
Citrus Fruit ◽  
Penicillium Digitatum ◽  
Antifungal Protein ◽  
Penicillium Expansum ◽  
Wild Type ◽  
Phenotypic Differences ◽  
Antifungal Proteins ◽  
Ascomycete Fungi ◽  
In Vitro Antifungal Activity

Antifungal proteins (AFPs) from ascomycete fungi could help the development of antimycotics. However, little is known about their biological role or functional interactions with other fungal biomolecules. We previously reported that AfpB from the postharvest pathogen Penicillium digitatum cannot be detected in the parental fungus yet is abundantly produced biotechnologically. While aiming to detect AfpB, we identified a conserved and novel small Secreted Cysteine-rich Anionic (Sca) protein, encoded by the gene PDIG_23520 from P. digitatum CECT 20796. The sca gene is expressed during culture and early during citrus fruit infection. Both null mutant (Δsca) and Sca overproducer (Scaop) strains show no phenotypic differences from the wild type. Sca is not antimicrobial but potentiates P. digitatum growth when added in high amounts and enhances the in vitro antifungal activity of AfpB. The Scaop strain shows increased incidence of infection in citrus fruit, similar to the addition of purified Sca to the wild-type inoculum. Sca compensates and overcomes the protective effect of AfpB and the antifungal protein PeAfpA from the apple pathogen Penicillium expansum in fruit inoculations. Our study shows that Sca is a novel protein that enhances the growth and virulence of its parental fungus and modulates the activity of AFPs.

scholarly journals First Report of Penicillium carneum Causing Blue Mold on Stored Apples in Pennsylvania

Plant Disease ◽  
2012 ◽  
Vol 96 (12) ◽  
pp. 1823-1823 ◽  
Author(s):  
K. A. Peter ◽  
I. Vico ◽  
V. Gaskins ◽  
W. J. Janisiewicz ◽  
R. A. Saftner ◽  
...  
Keyword(s):  
Negative Control ◽  
Penicillium Expansum ◽  
Malt Extract ◽  
Conidial Suspension ◽  
Blue Mold ◽  
Separate Species ◽  
First Report ◽  
Golden Delicious ◽  
Apple Fruits ◽  
Β Tubulin

Blue mold decay occurs during long term storage of apples and is predominantly caused by Penicillium expansum Link. Apples harvested in 2010 were stored in a controlled atmosphere at a commercial Pennsylvania apple packing and storage facility, and were examined for occurrence of decay in May 2011. Several decayed apples from different cultivars, exhibiting blue mold symptoms with a sporulating fungus were collected. One isolate recovered from a decayed ‘Golden Delicious’ apple fruit was identified as P. carneum Frisvad. Genomic DNA was isolated, 800 bp of the 3′ end of the β-tubulin locus was amplified using gene specific primers and sequenced (4). The recovered nucleotide sequence (GenBank Accession No. JX127312) indicated 99% sequence identity with P. carneum strain IBT 3472 (GenBank Accession No. JF302650) (3). The P. carneum colonies strongly sporulated and had a blue green color on potato dextrose agar (PDA), Czapek yeast autolysate agar (CYA), malt extract agar (MEA), and yeast extract sucrose agar (YES) media at 25°C after 7 days. The colonies also had a beige color on plate reverse on CYA and YES media. The species tested positive for the production of alkaloids, as indicated by a violet reaction for the Ehrlich test, and grew on CYA at 30°C and on Czapek with 1,000 ppm propionic acid agar at 25°C; all of which are diagnostic characters of this species (2). The conidiophores were hyaline and tetraverticillate with a finely rough stipe. Conida were produced in long columns, blue green, globose, and averaged 2.9 μm in diameter. To prove pathogenicity, Koch's postulates were conducted using 20 ‘Golden Delicious’ apple fruits. Fruits were washed, surface sterilized with 70% ethanol, and placed onto fruit trays. Using a nail, 3-mm wounds were created and inoculated with 50 μl of a 106/ml conidial suspension or water only as a negative control. The fruit trays were placed into boxes and were stored in the laboratory at 20°C for 7 days. The inoculated fruit developed soft watery lesions, with hard defined edges 37 ± 4 mm in diameter. The sporulating fungus was reisolated from infected tissue of all conidia inoculated apples and confirmed to be P. carneum by polymerase chain reaction (PCR) using the β-tubulin locus as described. Water inoculated control apples were symptomless. Originally grouped with P. roqueforti, P. carneum was reclassified in 1996 as a separate species (1). P. carneum is typically associated with meat products, beverages, and bread spoilage and produces patulin, which is not produced by P. roqueforti (1,2). Our isolate of P. carneum was susceptible to the thiabendazole (TBZ) fungicide at 250 ppm, which is below the recommended labeled application rate of 600 ppm. The susceptibility to TBZ suggests that this P. carneum isolate has been recently introduced because resistance to TBZ has evolved rapidly in P. expansum (4). To the best of our knowledge, P. carneum has not previously been described on apple, and this is the first report of P. carneum causing postharvest decay on apple fruits obtained from storage in Pennsylvania. References: (1) M. Boyson et al. Microbiology 142:541, 1996. (2) J. C. Frisvad and R. A. Samson. Stud. Mycol. 49:1, 2004. (3) B. G. Hansen et al. BMC Microbiology 11:202, 2011. (4) P. L. Sholberg et al. Postharvest Biol. Technol. 36:41, 2005.

scholarly journals Biocontrol Efficacy of Antagonist Yeasts to Gray Mold and Blue Mold on Apples and Pears in Controlled Atmospheres

Plant Disease ◽  
2002 ◽  
Vol 86 (8) ◽  
pp. 848-853 ◽  
Author(s):  
Shiping Tian ◽  
Qing Fan ◽  
Yong Xu ◽  
Haibo Liu
Keyword(s):  
Pathogenic Fungi ◽  
Storage Conditions ◽  
Gray Mold ◽  
Penicillium Expansum ◽  
Cryptococcus Albidus ◽  
Blue Mold ◽  
Controlled Atmospheres ◽  
Biocontrol Efficacy ◽  
Significant Difference ◽  
Apple Fruits

Biocontrol capability of the yeasts Trichosporon sp. and Cryptococcus albidus against Botrytis cinerea and Penicillium expansum was evaluated in apple (cv. Golden Delicious) and pear (cv. Jingbai) fruits at 1°C in air and under controlled atmospheres (CA) with 3% O2 + 3% CO2 or 3% O2 + 8% CO2. Trichosporon sp. controlled gray mold and blue mold of apple fruits more effectively than C. albidus (P < 0.05). Apple fruits treated with Trichosporon sp. and C. albidus had a lower incidence of gray mold rot than blue mold rot in the same storage conditions. Biocontrol efficacy of the yeasts for controlling gray mold and blue mold was better in apples than in pears. Populations of the yeasts in drop-inoculated wounds in fruits increased rapidly after 20 days at 1°C both in air and in CA conditions. There was no significant difference in colony diameters of the two pathogens cultured in 0 to 15% CO2 concentrations after 7 days at 20°C, but the colony diameter of both B. cinerea and P. expansum at 20% CO2 was significantly less than in other treatments (P < 0.05). CA with 3% O2 + 8% CO2 inhibited the pathogenic fungi more than CA with 3% O2 + 3% CO2.

Production of Mycotoxins by Penicillium expansum Inoculated into Apples

2008 ◽  
Vol 71 (8) ◽  
pp. 1714-1719 ◽  
Author(s):  
MITSURU WATANABE
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
High Performance ◽  
Hplc Analysis ◽  
Penicillium Expansum ◽  
Liquid Chromatography Mass Spectrometry ◽  
Blue Mold ◽  
Positive Ion ◽  
Uv And Fluorescence Detection ◽  
Apple Fruits

We investigated the production of mycotoxins in apple fruits inoculated with spores of 40 strains of apple blue mold, Penicillium expansum. Patulin and citrinin contents in the extracts from apples stored at 25°C for 12 days after inoculation were determined by high-performance liquid chromatography (HPLC) analysis with UV and fluorescence detection. Patulin and citrinin were produced by 90% (36) and 80% (32) of the 40 strains, indicating that P. expansum is a consistent producer of these mycotoxins. The patulin content in the extracts was substantially higher than the citrinin content. Other mycotoxins whose production in pure culture has been reported were simultaneously detected with high-resolution liquid chromatography–mass spectrometry (LC-MS) analysis with the positive ion mode of electrospray ionization. Along with patulin and citrinin, expansolides A and B were identified based on the HPLC and LC-MS spectral data and detected in 88% (35) of the extracts. The results indicate that P. expansum is a consistent producer of expansolides A and B in rotten areas of apple fruits. The findings raise the possibility that products from decayed apples might contain expansolides A and B in addition to patulin and citrinin.

scholarly journals Characterization of Fludioxonil-Resistant and Pyrimethanil-Resistant Phenotypes of Penicillium expansum from Apple

2008 ◽  
Vol 98 (4) ◽  
pp. 427-435 ◽  
Author(s):  
H. X. Li ◽  
C. L. Xiao
Keyword(s):  
Osmotic Stress ◽  
The United States ◽  
Apple Fruit ◽  
Penicillium Expansum ◽  
Postharvest Disease ◽  
Wild Type ◽  
Blue Mold ◽  
Pome Fruit ◽  
Development Of Resistance ◽  
Resistant Mutants

Penicillium expansum is the primary cause of blue mold, a major postharvest disease of apple. Fludioxonil and pyrimethanil are two newly registered postharvest fungicides for pome fruit in the United States. To evaluate the potential risk of resistance development in P. expansum to the new postharvest fungicides, one isolate of each of thiabendazole-resistant (TBZ-R) and -sensitive (TBZ-S) P. expansum was exposed to UV radiation to generate fungicide-resistant mutants. Four fludioxonil highly-resistant mutants (EC50 > 1,000 μg/ml) and four pyrimethanil-resistant mutants (EC50 > 10 μg/ml) were tested for sensitivities to thiabendazole, fludioxonil, and pyrimethanil, and fitness parameters including mycelial growth, sporulation on potato dextrose agar (PDA), sensitivity to osmotic stress, and pathogenicity and sporulation on apple fruit. The stability of resistance of the mutants was tested on PDA and apple fruit. Efficacy of the three fungicides to control blue mold incited by the mutants was evaluated on apple fruit. Six fungicide-resistant phenotypes were identified among the parental wild-type isolates and their mutants based upon their resistance levels. All four fludioxonil highly-resistant mutants were sensitive to pyrimethanil and retained the same phenotypes of resistance to TBZ as the parental isolates. All four pyrimethanil-resistant mutants had a low level of resistance to fludioxonil with a resistance factor >15. The two pyrimethanil-resistant mutants derived from a TBZ-S isolate became resistant to TBZ at 5 μg/ml. After 20 successive generations on PDA and four generations on apple fruit, the mutants retained the same phenotypes as the original generations. All mutants were pathogenic on apple fruit at both 0 and 20°C, but fludioxonil highly-resistant mutants were less virulent and produced fewer conidia on apple fruit than pyrimethanil-resistant mutants and their parental wild-type isolates. Compared with the parental isolates, all four fludioxonil highly-resistant mutants had an increased sensitivity to osmotic stress on PDA amended with NaCl, while the pyrimethanil-resistant mutants did not. Pyrimethanil was effective against blue mold caused by fludioxonil-resistant mutants at both 0 and 20°C. Pyrimethanil and fludioxonil reduced blue mold incited by pyrimethanil-resistant mutants during 12-week storage at 0°C but were not effective at 20°C. TBZ was not effective against pyrimethanil-resistant mutants derived from TBZ-S wild-type isolates at room temperature but provided some control at 0°C. The results indicate that: (i) a fitness cost was associated with fludioxonil highly resistant mutants of P. expansum in both saprophytic and pathogenic phases of the pathogen but not pyrimethanil-resistant mutants; (ii) pyrimethanil possessed a higher risk than fludioxonil in the development of resistance in P. expansum; and (iii) triple resistance to the three apple-postharvest fungicides could emerge and become a practical problem if resistance to pyrimethanil develops in P. expansum populations.

scholarly journals Analytical study on Fungal Cellulase Produced by Penicillium Expansum grown on Malus Domestica (Apple Fruits)

2021 ◽  
Vol 4 (1) ◽  
pp. 1-10
Author(s):  
MR Adedayo ◽  
OV Ayilara
Keyword(s):  
Malus Domestica ◽  
Methyl Cellulose ◽  
Cellulase Activity ◽  
Apple Fruit ◽  
Penicillium Expansum ◽  
Cellulolytic Activity ◽  
Assay Condition ◽  
Bacterial Contaminants ◽  
Fungal Cellulase ◽  
Apple Fruits

The rise in world industrialization and the cost of importing enzyme by local industries have led to arise in the search for novel and native enzyme producing microorganisms. Cellulase is an enzyme that catalyzes the breaking down of carbon chains in cellulose and hemicellulose, this research therefore aimed at studying fungal cellulase produced by Penicillium expansum grown on malus domestica (apple fruits). Fresh apple fruit was allowed to deteriorate under laboratory condition until there was visible mould growth. The mould with desired features of the organism of interest was subcultured by direct plating on PDA plates to which 10 % streptomycin has been added to prevent bacterial contaminants. The plates were incubated at 28±2 0C for 7 days until a visible mass of blue mycelia appear. The isolate was further subcultured onto freshly prepared media until pure culture was obtained. Characterization and identification of isolate were done using macroscopy and microscopy techniques. The isolate was re-inoculated into healthy apple fruits and the fruits were incubated at temperature of 28±2 oC for 8 days. Cellulolytic activity was examined every day throughout the incubation period. Crude enzyme was extracted each day using standard methods. Carboxyl methyl cellulose was used as standard for the crude cellulase activity assay after extraction from the infected apple fruits using Dinitrosalicylic acid (DNSA). Culture parameters like pH and temperature were also optimized to determine their effect on cellulolytic activity of the fungus. Cellulase activity was defined as the amount of glucose produced in μmol/mg/min under the assay condition. The highest cellulase activity of 86.84±0.52 μmol/mg/min was observed on day 6 of incubation at 28±2 oC and at pH 7. In conclusion, it is evident from this research that P. expansum isolated could be used as potential novel organism for industrial production of cellulase under optimized fermentation conditions.

scholarly journals Integrated management of causal agents of postharvest fruit rot of apple

2011 ◽  
Vol 26 (4) ◽  
pp. 289-299 ◽  
Author(s):  
Mila Grahovac ◽  
Dusanka Indjic ◽  
Brankica Tanovic ◽  
Sanja Lazic ◽  
Slavica Vukovic ◽  
...  
Keyword(s):  
Fungal Pathogens ◽  
Colletotrichum Gloeosporioides ◽  
Integrated Management ◽  
Poor Quality ◽  
Phytopathogenic Fungi ◽  
Fruit Rot ◽  
Penicillium Expansum ◽  
Phytopathogenic Fungus ◽  
Economic Losses ◽  
Apple Fruits

One of the major causes of poor quality and fruit loss (during storage and transport) are diseases caused by phytopathogenic fungi. Economic losses which are the consequence of the phytopathogenic fungus activity after harvest exceed the losses in the field. The most important postharvest fungal pathogens of apple fruits are: Botrytis cinerea Pers. ex Fr., Penicillium expansum (Lk.) Thom., Cryptosporiopsis curvispora (Peck.) Grem., Colletotrichum gloeosporioides (Penz.) Sacc., Monilinia sp., Gloeosporium album Osterw, Alternaria alternata (Fr.) Keissler, Cladosporium herbarium Link., Cylindrocarpon mali (Alles.) Wollenw., Stemphylium botryosum Wallr. The use of available protection technologies can significantly reduce losses caused by pathogens in storage. The concept of integrated pest management (IPM) in apple fruits i.e. sustainable approach in control of causal agents of postharvest fruit rot, using cultural, physical, biological and chemical measures, to minimize economic, health and risks to consumers and environment, is presented in the paper.

Efficacy of salicylic acid to reduce Penicillium expansum inoculum and preserve apple fruits

2016 ◽  
Vol 221 ◽  
pp. 54-60 ◽  
Author(s):  
Argus Cezar da Rocha Neto ◽  
Caroline Luiz ◽  
Marcelo Maraschin ◽  
Robson Marcelo Di Piero
Keyword(s):  
Salicylic Acid ◽  
Penicillium Expansum ◽  
Apple Fruits
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