Production of a polygalacturonase complex by Botryodiplodia theobromae and its involvement in the rot of sweet potato

Arinze, A. E.; Smith, Ian M.

doi:10.1016/0048-4059(79)90002-x

Cited by 20 publications

(8 citation statements)

References 24 publications

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“…These enzymes are upregulated by the plant hormone ethylene (37,59,60). As a pathogen of woody plants, the production and secretion of cell wall-digesting enzymes, including polygalacturonase, cellulase, and ␤-glucosidase by diplodia, has been well documented (32,34,61,62). These diplodia-produced enzymes could contribute to fruit abscission directly by degrading the cell wall and middle lamella in the abscission zone, and they may also indirectly impact fruit abscission by inducing the fruit to produce ethylene, which in turn induces the plant abscission zone to produce cell wall-degrading enzymes.…”

Section: Figmentioning

confidence: 99%

High Incidence of Preharvest Colonization of Huanglongbing-Symptomatic Citrus sinensis Fruit by Lasiodiplodia theobromae (Diplodia natalensis) and Exacerbation of Postharvest Fruit Decay by That Fungus

Zhao

Bai

McCollum

et al. 2015

Appl Environ Microbiol

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Huanglongbing (HLB), presumably caused by the bacterium "Candidatus Liberibacter asiaticus," is a devastating citrus disease associated with excessive preharvest fruit drop. Lasiodiplodia theobromae (diplodia) is the causal organism of citrus stem end rot (SER). The pathogen infects citrus fruit under the calyx abscission zone (AZ-C) and is associated with cell wall hydrolytic enzymes similar to plant enzymes involved in abscission. By means of DNA sequencing, diplodia was found in "Ca. Liberibacter asiaticus"-positive juice from HLB-symptomatic fruit (S) but not in "Ca. Liberibacter asiaticus"-negative juice. Therefore, the incidence of diplodia in fruit tissues, the impact on HLB-related postharvest decay, and the implications for HLB-related preharvest fruit drop were investigated in Hamlin and Valencia oranges. Quantitative PCR results (qPCR) revealed a significantly (P < 0.001) greater incidence of diplodia in the AZ-C of HLB-symptomatic (S; "Ca. Liberibacter asiaticus" threshold cycle [C T ] of <30) than in the AZ-C of in asymptomatic (AS; "Ca. Liberibacter asiaticus" C T of >30) fruit. In agreement with the qPCR results, 2 weeks after exposure to ethylene, the incidences of SER in S fruit were 66.7% (Hamlin) and 58.7% (Valencia), whereas for AS fruit the decay rates were 6.7% (Hamlin) and 5.3% (Valencia). Diplodia colonization of S fruit AZ-C was observed by scanning electron microscopy and confirmed by PCR test and morphology of conidia in isolates from the AZ-C after surface sterilization. Diplodia C T values were negatively correlated with ethylene production (R ‫؍‬ ؊0.838 for Hamlin; R ‫؍‬ ؊0.858 for Valencia) in S fruit, and positively correlated with fruit detachment force (R ‫؍‬ 0.855 for Hamlin; R ‫؍‬ 0.850 for Valencia), suggesting that diplodia colonization in AZ-C may exacerbate HLB-associated preharvest fruit drop. C itrus huanglongbing (HLB; also known as citrus greening) is one of the most devastating diseases of citrus and has spread throughout the major citrus-producing regions in Asia, Africa, and the Americas, causing great losses for the citrus industry worldwide (1). HLB is associated with "Candidatus Liberibacter" spp., which are Gram-negative, phloem-limited bacteria (2, 3). The Asian form of HLB is currently present in the United States, and the causal pathogen, bacterium "Candidatus Liberibacter asiaticus," was first confirmed in Southeast Florida in 2005 (1) and now is prevalent in all Florida citrus-growing areas in the state. HLB disease causes substantial economic loss by debilitating the productive capacity and shortening the life span of infected trees, promoting fruit drop and reducing fruit quality (4). Yield reduction can reach 30 to 100%, depending on the proportion of the canopy affected and the age of the trees during inoculation (1, 5).HLB-diseased citrus plants develop a multitude of symptoms. Leaf symptoms include chlorosis, which commonly appears in an asymmetric pattern referred to as "blotchy mottle" (4). Chlorosis may typically appear on a single branch and subse...

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Section: Figmentioning

confidence: 99%

High Incidence of Preharvest Colonization of Huanglongbing-Symptomatic Citrus sinensis Fruit by Lasiodiplodia theobromae (Diplodia natalensis) and Exacerbation of Postharvest Fruit Decay by That Fungus

Zhao

Bai

McCollum

et al. 2015

Appl Environ Microbiol

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“…Enzyme multiplicity and the diversity between the "in vivo" and "in witro" patterns have been observed in many other cases (BATEMAN 1972;HARMANN and CORDEN 1972;CERVONE et al 1977;ARINZE and SMITH 1979;BYRDE 1979;MAGRO, DI LENNA and MARCIANO 1979;BROOKHOUSER, HANCOCK and WEINHOLD 1980;MAGRO et al 1980;BARTHE, CANTENYS and TouzB 1981). Enzyme multiplicity has been interpreted as the result of the evolution in order to provide metabolic flexibility in a changeable environment (SCANDALIOS 1975).…”

Section: Discussionmentioning

confidence: 89%

Cell wall‐degrading enzymes produced by Seiridium cardinale, agent of the cypress canker

Magro

Lenna

Marciano

1982

European Journal of Forest Pathology

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“…L'ACS et l'acide caféique sont des orthodiphénols qui représentent des substrats préférentiels des polyphénoloxydases ( Harborne, 1989). Les produits d'oxydation des composés phénoliques sont plus toxiques vis‐à‐vis des microorganismes que leurs composés parentaux ( Harborne, 1989) et jouent un rôle important dans l'inactivation des enzymes lytiques ( Hunter, 1978; Arinze et Smith, 1979; Harborne, 1989). L'inhibition des enzymes hydrolytiques parasitaires par les produits d'oxydation des composés phénoliques est signalée par ailleurs dans plusieurs interactions hôte × parasite ( Byrde et al, 1960; Leatham et al, 1980; Friend, 1981; Harborne, 1989; El Modafar et al, 1996).…”

Section: Discussionunclassified

Effet de L'acide Caféoylshikimique des Racines du Palmier Dattier sur L'activité et la Production des Enzymes Hydrolytiques de Fusarium oxysporum f. sp. albedinis

Modafar¹,

Tantaoui

Boustani

2000

Journal of Phytopathology

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Résumé L'acide caféoylshikimique (ACS), composé phénolique soluble majeur des racines du palmier dattier, représente l'un des facteurs de résistance de l'hôte au Fusarium oxysporum f. sp. albedinis. L'ACS est testéà différentes concentrations (0,25 à 3 µ mol/ml) sur l'activité et la production d'enzymes hydrolytiques de F. oxysporum f. sp. albedinis dans le filtrat de culture. Les enzymes étudiées sont les protéases, les cellulases, les pectineméthyl‐estérases (PME), les polygalacturonases (PG) et les polygalacturonate trans‐éliminases (PGTE). Les résultats obtenus montrent que l'ACS affecte très peu l'activité des différentes enzymes alors qu'il réduit fortement leur production. La croissance mycélienne du champignon est également affectée par l'ACS, mais elle ne permet pas d'expliquer à elle seule la forte réduction de la production des hydrolases. Afin d'expliquer cet effet différentiel de l'ACS sur l'activité et la production d'enzymes lytiques parasitaires, nous avons testé d'une part, l'effet des produits d'hydrolyse de l'ACS (acide caféique, acide shikimique) et d'autre part, l'effet des produits d'oxydation de l'ACS (quinones) obtenus par oxydation via la tyrosinase. Les résultats obtenus montrent que l'acide shikimique n'a pas d'effet significatif sur l'activité des hydrolases et ne présente qu'une faible inhibition de leur production. Quant à l'acide caféique, il présente un pouvoir inhibiteur plus important sur l'activité des différentes enzymes que celui de l'ACS et son effet inhibiteur se manifeste davantage sur leur production. L'oxydation de l'ACS par la tyrosinase se traduit par une forte inhibition de l'activité des différentes enzymes étudiées. Cette inhibition est sensiblement comparable à celle observée par l'ACS non oxydé sur la production des enzymes. De même, l'acide caféique oxydé manifeste un effet inhibiteur plus important sur l'activité des hydrolases que celui de l'acide caféique non oxydé. L'ensemble de ces résultats suggère que l'ACS génère des produits d'hydrolyse (notamment l'acide caféique) et des produits d'oxydation (quinones) qui inhibent l'activité des enzymes protéolytiques, cellulolytiques et pectinolytiques produites par F. oxysporum f. sp. albedinis dans le milieu de culture.

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Production of a polygalacturonase complex by Botryodiplodia theobromae and its involvement in the rot of sweet potato

Cited by 20 publications

References 24 publications

High Incidence of Preharvest Colonization of Huanglongbing-Symptomatic Citrus sinensis Fruit by Lasiodiplodia theobromae (Diplodia natalensis) and Exacerbation of Postharvest Fruit Decay by That Fungus

High Incidence of Preharvest Colonization of Huanglongbing-Symptomatic Citrus sinensis Fruit by Lasiodiplodia theobromae (Diplodia natalensis) and Exacerbation of Postharvest Fruit Decay by That Fungus

Cell wall‐degrading enzymes produced by Seiridium cardinale, agent of the cypress canker

Effet de L'acide Caféoylshikimique des Racines du Palmier Dattier sur L'activité et la Production des Enzymes Hydrolytiques de Fusarium oxysporum f. sp. albedinis

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