Pectolytic, cellulytic and proteolytic activities expressed by cultures of Endothia parasitica, and inhibition of these activities by components extracted from Chinese and American chestnut inner bark

McCarroll, D R; Thor, Eyvind

doi:10.1016/0048-4059(85)90011-6

Cited by 24 publications

(15 citation statements)

References 33 publications

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“…Cooper (1977) and Cooper and Wood (1975) reported that cellulase is the latest cell-wall degrading enzyme produced during pathogenesis. These results, along with those of McCarroll and Thor (1985) support our titidings concerning the importance of cellulase in the saprophytic phase of the disease. In the present work we itivestigated cellulase activity iti itifected trees from a novel point of view; changes in the cellulytic activity along the invaded stem.…”

Section: Discussionsupporting

confidence: 83%

The Role of Cellulase (Endo‐1,4‐β‐Glucanase) in Gummosis Diseases in Apricot

Rotem¹,

Shoseyov²,

Sztejnberg³

1995

Journal of Phytopathology

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Apricot gummosis pathogens — the fungi Hendersonula toruloidea, a Cytosporina sp. and a Cytospora sp., produce cellulase (endo‐1,4‐β‐glucanase, carboxymethylcellulase, CMCase) in culture. Cytospora sp. produced significantly lower amounts of cellulase than H. toruloidea and Cytosporina sp. The tendency of cellulase accumulation inside apricot stems infected with either H. toruloidea or Cytosporina sp. is similar: most of the cellulase was found in the necrotic area, whereas comparatively small amounts accumulated at the advancing edge of the disease symptom. H. toruloidea produces cellulase with a molecular mass of 76 kDa.

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Section: Discussionsupporting

confidence: 83%

The Role of Cellulase (Endo‐1,4‐β‐Glucanase) in Gummosis Diseases in Apricot

Rotem¹,

Shoseyov²,

Sztejnberg³

1995

Journal of Phytopathology

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“…Most, including C. parasitica, require wounds in the bark for entry into the host. Bark, similarly, is a major barrier to the eruption of fruiting bodies, even though this eruption may be facilitated by the enzymatic degradation of host tissues that occurs during the colonization process (16). Our results indicate that such digestion of host tissue by C. parasitica was insufficient to allow eruption of the fruiting bodies.…”

Section: Discussionmentioning

confidence: 41%

A Hydrophobin of the Chestnut Blight Fungus, Cryphonectria parasitica , Is Required for Stromal Pustule Eruption

Kazmierczak

Kim

Turina³

et al. 2005

Eukaryot Cell

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Hydrophobins are abundant small hydrophobic proteins that are present on the surfaces of many filamentous fungi. The chestnut blight pathogen Cryphonectria parasitica was shown to produce a class II hydrophobin, cryparin. Cryparin is the most abundant protein produced by this fungus when grown in liquid culture. When the fungus is growing on chestnut trees, cryparin is found only in the fungal fruiting body walls. Deletion of the gene encoding cryparin resulted in a culture phenotype typical of hydrophobin deletion mutants of other fungi, i.e., easily wettable (nonhydrophobic) hyphae. When grown on the natural substrate of the fungus, however, cryparin-null mutation strains were unable to normally produce its fungal fruiting bodies. Although the stromal pustules showed normal development initially, they were unable to erupt through the bark of the tree. The hydrophobin cryparin thus plays an essential role in the fitness of this important plant pathogen by facilitating the eruption of the fungal fruiting bodies through the bark of its host tree.The exterior surfaces of plants are formidable barriers to pathogens. Most plant pathogens are unable to directly penetrate these barriers, and those that can penetrate these barriers have evolved remarkable strategies for doing so. For example, Plasmodiophora brassicae (1) penetrates the host wall by puncturing it with a specialized structure called the stachel. Magnaporthe grisea, the rice blast pathogen, produces another type of specialized structure, the appressorium, which penetrates the plant cuticle with a peg that develops unusually high hydrostatic pressures (26). To exit a plant, the same barriers that met the pathogen on entry must once again be crossed. Some pathogens, such as the late-blight pathogen Phytophthora infestans, sporulate by exiting natural openings on the plant surface. Little is known, however, of how those fungi that sporulate by erupting through host tissues are able to breach the plant surface barriers. It is known that microbial pathogens must be able to exit their hosts and gain access to new hosts in order to successfully complete the disease cycle.The search for pathogenicity factors of fungal plant pathogens has focused largely upon understanding how the fungus invades its host (8,13,20,29). Much less attention has been paid to the role of sporulation as a potential target for control of disease. From our study of cryparin, a cell surface hydrophobin of the plant pathogen Cryphonectria parasitica, we report the involvement of this protein in the normal egress of the fungus from infected trees. This protein thus acts as a pathogenicity factor since it is necessary for the successful completion of the pathogen's disease cycle.The ascomycete C. parasitica is one of the most devastating plant pathogens of recorded history; it has essentially eliminated its host, the American chestnut, from its natural range. This fungus enters the tree through wounds and, in the process of colonizing the wound, forms a hyphal fan with which the fungus invade...

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“…Canker formation by the chestnut blight fungus involves maceration and destruction of host tissues in advance of penetrating fungal hyphae (12). Thus, a logical prediction is that secreted cell wall-degrading enzymes have an important role in disease expression (16). However, the diversity and likely redundancy of hydrolytic enzymes produced by C. parasitica, and phytopathogenic fungi in general, complicate attempts to demonstrate the importance of specific enzymes or classes of enzymes in fungal virulence.…”

Section: Discussionmentioning

confidence: 99%

“…Several studies designed to identify the underlying basis for host susceptibility versus resistance and hypovirus-mediated hypovirulence have focused on the role of fungus-encoded plant cell wall-degrading enzymes. In this regard, C. parasitica has been shown to produce and secrete a number of hydrolytic enzymes, including the rennin-like protease endothiapepsin (26), cellulases (16,25), polygalacturonase (PG) (10), and cutinase (22). Of these, PG activity has been characterized in the greatest detail and measured under the most relevant experimental conditions.…”

mentioning

confidence: 99%

Cloning and targeted disruption of enpg-1, encoding the major in vitro extracellular endopolygalacturonase of the chestnut blight fungus, Cryphonectria parasitica

Gao

Choi

Shain

et al. 1996

Appl Environ Microbiol

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The gene enpg-1, encoding the major extracellular endopolygalacturonase (endoPG) purified from culture filtrates of the chestnut blight fungus, Cryphonectria parasitica, was cloned and characterized. The deduced mature enpg-1 protein product, ENPG-1, had a calculated molecular mass of 34.5 kDa and a pI of 7.2, consistent with empirically derived values for the purified enzyme, and had 66% identity with an endoPG from the maize pathogen Cochliobolus carbonum. Targeted disruption of enpg-1 was accomplished by homologous recombination with a cloned copy of the gene that contained the Escherichia coli hygromycin B phosphotransferase gene (hph) inserted into exon 1. enpg-1 disruption resulted in no reduction in canker formation on dormant American chestnut stems. Unexpectedly, the level of polygalacturonase (PG) activity measured in cankered bark tissue infected with enpg-1 disruptants was indistinguishable from that found in canker tissue infected with virulent strain EP155. Isoelectric focusing and activity gel analysis of PG activity extracted from canker bark tissue revealed ENPG-1 to be a minor (less than 5%) activity component in tissue infected with the virulent strain and to be absent in tissue infected with the disruption mutants. The predominant activity in both canker samples consisted of two previously undetected acidic PG forms that appear absent in C. parasitica culture filtrates. We conclude from these results that the major C. parasitica extracellular endoPG produced in culture, ENPG-1, does not play a significant role in fungal virulence. However, the identification of two acidic PG activities expressed predominantly, if not exclusively, in planta provides new opportunities for examining the importance of PGs in C. parasitica pathogenesis.

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Pectolytic, cellulytic and proteolytic activities expressed by cultures of Endothia parasitica, and inhibition of these activities by components extracted from Chinese and American chestnut inner bark

Cited by 24 publications

References 33 publications

The Role of Cellulase (Endo‐1,4‐β‐Glucanase) in Gummosis Diseases in Apricot

The Role of Cellulase (Endo‐1,4‐β‐Glucanase) in Gummosis Diseases in Apricot

A Hydrophobin of the Chestnut Blight Fungus, Cryphonectria parasitica , Is Required for Stromal Pustule Eruption

Cloning and targeted disruption of enpg-1, encoding the major in vitro extracellular endopolygalacturonase of the chestnut blight fungus, Cryphonectria parasitica

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