Abstract
ABSTRACT The potential of the endophytic bacterium Serratia plymuthica strain R1GC4 in stimulating defense reactions in cucumber (Cucumis sativus) seedlings inoculated with the soilborne pathogen Pythium ultimum was explored at the cellular level. Bacterial treatment prior to Pythium inoculation resulted in less seedling disease development as compared with that in nontreated control plants, in which typical root symptoms were visible by 3 days after inoculation with the pathogen. Histological investigations of root samples revealed striking differences in the extent of plant defense reactions between bacterized and nonbacterized plants. These observations were further confirmed at the ultrastructural level with the demonstration that restriction of fungal colonization to the outermost root tissues of bacterized seedlings correlated with the deposition of enlarged callose-enriched wall appositions at sites of potential pathogen penetration and the accumulation of an osmiophilic material in the colonized areas. Hyphae of the pathogen, surrounded by this electron-opaque material, exhibited considerable changes including cytoplasm disorganization and, in many cases, loss of the protoplasm. However, labeling with the beta-1,4-exoglucanase resulted in a regular labeling of Pythium cell walls, even at a time when these walls were entirely coated by the osmiophilic material. This material was also found to infiltrate into the invading hyphae to form either an internal coating of the cell wall or a network of polymorphic droplets in the area previously occupied by the cytoplasm. Cytochemical investigations revealed that callose, pectin, and cellulose appeared in the wall appositions. In addition, glucosides, lipids, and phenolics were detected in the electron-dense aggregates forming the core of most wall appositions. Finally, galactose residues were among the minor polysaccharidic compounds detected in the wall appositions. Evidence is provided in this study showing that treatment with S. plymuthica sensitizes susceptible cucumber plants to react more rapidly and more efficiently to Pythium attack through the formation of physical and chemical barriers at sites of potential fungal entry.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 10
Claim · model-written summary
Serratia pretreatment reduced cucumber seedling disease after Pythium inoculation relative to untreated plants.
- Taxon
- Cucumber
Cucumis sativust0 - Treatment
- Bacterial treatment prior to Pythium inoculatione0
- Second interactor
- Serratia plymuthica
Serratia plymuthicat0biocontrol_agente0 - Outcome
- seedling disease developmente0
- Direction
- lesse0
- Comparator
- nontreated control plantse0
.jpg?width=60){kind=small}
PythiumOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“Bacterial treatment prior to Pythium inoculation resulted in less seedling disease development as compared with that in nontreated control plants”
t0“Cucumber: Beneficial Effect of the Endophytic Bacterium Serratia plymuthica on the Protection Against Infection by Pythium ultimum”
Claim · model-written summary
Bacterized seedlings restricted fungal colonization to outer root tissues.
- Taxon
- CucumberCucumis sativust0
- Organ / stage
- root tissuese0
- Treatment
- bacterized seedlingse0
- Interactor
- Pythium ultimumGlobisporangium ultimumt0pathogene0
- Second interactor
- Serratia plymuthicaSerratia plymuthicat0biocontrol_agente0
- Outcome
- restriction of fungal colonization to the outermost root tissuese0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“restriction of fungal colonization to the outermost root tissues of bacterized seedlings correlated with the deposition of enlarged callose-enriched wall appositions”
t0“Cucumber: Beneficial Effect of the Endophytic Bacterium Serratia plymuthica on the Protection Against Infection by Pythium ultimum”
Claim · model-written summary
Restricted colonization correlated with callose rich wall appositions and osmiophilic material.
- Taxon
- CucumberCucumis sativust0
- Organ / stage
- root tissuese0
- Outcome
- restriction of fungal colonizatione0
- Qualifier
- deposition of enlarged callose-enriched wall appositionse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“restriction of fungal colonization to the outermost root tissues of bacterized seedlings correlated with the deposition of enlarged callose-enriched wall appositions at sites of potential pathogen penetration and the accumulation of an osmiophilic material in the colonized areas.”
t0“Cucumber”
Claim · model-written summary
Hyphae surrounded by electron opaque material showed cytoplasmic disorganization and often protoplasm loss.
- Taxon
- CucumberCucumis sativust0
- Interactor
- pathogene0pathogen
- Outcome
- cytoplasm disorganization and, in many cases, loss of the protoplasme0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Hyphae of the pathogen, surrounded by this electron-opaque material, exhibited considerable changes including cytoplasm disorganization and, in many cases, loss of the protoplasm.”
t0“Cucumber”
Claim · model-written summary
Pythium cell walls were regularly labeled by beta-1,4-exoglucanase despite their osmiophilic coating.
- Taxon
- CucumberCucumis sativust0
- Gene
- beta-1,4-exoglucanasee0
- Outcome
- regular labeling of Pythium cell wallse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“labeling with the beta-1,4-exoglucanase resulted in a regular labeling of Pythium cell walls, even at a time when these walls were entirely coated by the osmiophilic material.”
t0“Cucumber”
Claim · model-written summary
Osmiophilic material infiltrated invading hyphae and formed an internal wall coating or polymorphic droplets.
- Taxon
- CucumberCucumis sativust0
- Interactor
- Pythium ultimumGlobisporangium ultimumt0pathogene0
- Outcome
- internal coating of the cell wall or a network of polymorphic dropletse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This material was also found to infiltrate into the invading hyphae to form either an internal coating of the cell wall or a network of polymorphic droplets in the area previously occupied by the cytoplasm.”
t0“Cucumber: Beneficial Effect of the Endophytic Bacterium Serratia plymuthica on the Protection Against Infection by Pythium ultimum”
Claim · model-written summary
Wall appositions contained callose, pectin and cellulose.
- Taxon
- CucumberCucumis sativust0
- Outcome
- callose, pectin, and cellulose appeared in the wall appositionse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“callose, pectin, and cellulose appeared in the wall appositions.”
t0“Cucumber”
Claim · model-written summary
Wall apposition cores contained glucosides, lipids and phenolics.
- Taxon
- CucumberCucumis sativust0
- Outcome
- glucosides, lipids, and phenolicse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“glucosides, lipids, and phenolics were detected in the electron-dense aggregates forming the core of most wall appositions.”
t0“Cucumber”
Claim · model-written summary
Wall appositions also contained galactose residues among minor polysaccharides.
- Taxon
- CucumberCucumis sativust0
- Outcome
- galactose residuese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“galactose residues were among the minor polysaccharidic compounds detected in the wall appositions.”
t0“Cucumber”
Claim · model-written summary
The authors conclude that Serratia sensitizes cucumber to faster, more effective barriers against Pythium.
- Taxon
- cucumberCucumis sativuse0
- Treatment
- treatment with S. plymuthicae0
- Second interactor
- S. plymuthicaSerratia plymuthicae0biocontrol_agent
- Outcome
- react more rapidly and more efficiently to Pythium attacke0
- Qualifier
- formation of physical and chemical barrierse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“treatment with S. plymuthica sensitizes susceptible cucumber plants to react more rapidly and more efficiently to Pythium attack through the formation of physical and chemical barriers at sites of potential fungal entry.”
The same questions in other papers
Pythium · disease · Cucumis sativus (cucumber)Positive and negative results
1 in the opposite direction
- negative
inoculation · disease · Cucumis sativus (cucumber)Positive and negative results
49 papers in the same direction as this paper · 33 in the opposite direction
- negative
- negative
- negative
79 papers more in this group
See all 83 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.