Abstract
Segments from dark-grown cucumber (Cucumis sativus L.) hypocotyls were used to study defense reactions occurring upon fungal infection and induced by elicitors in the same tissue. The segments were rendered resistant to infection by Colletotrichum lagenarium either by growing the seedlings in the presence of dichloroisonicotinic acid (DCIA) or by preincubation of the cut segments with DCIA, salicylic acid (SA), or 5-chlorosalicylic acid (5CSA). This resistance appears to be due mainly to inhibition of fungal penetration into epidermal cells. In the resistant hypocotyl segments, the fungus induced, at the time of attempted penetration, an increased deposition of phenolics, which were visualized by autofluorescence. These phenolics were located mainly in the epidermal cell wall around and in the emerging papillae below appressoria and were quantified either as lignin-like polymers by the thioglycolic acid method or as 4-OH-benzaldehyde, 4-OH-benzoic, or 4-coumaric acid liberated upon treatment with alkali at room temperature. Pretreatment with DCIA, SA, and 5CSA induced little chitinase activity, but this activity greatly increased in resistant tissues upon subsequent infection. These observations indicate that resistance is associated with an improved perception of the pathogen stimulus resulting in the enhanced induction of diverse defense reactions. When the cut segments were pretreated with DCIA, SA, or 5CSA and then split and incubated with chitosan fragments, the deposition of cell wall phenolics was also enhanced. These pretreated and split segments also exhibited an increase in the rapid production of activated oxygen species induced by an elicitor preparation from Phytophthora megasperma f. sp. Glya. Pretreatment of the segments with methyl jasmonate neither induced resistance nor enhanced induction of cell wall phenolics upon fungal infection, although we observed in the corresponding split segments some increase in chitosan-induced cell wall phenolics and in elicitor-induced rapid production of activated oxygen species.
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Claims 12
Claim · model-written summary
Growing cucumber seedlings with DCIA rendered hypocotyl segments resistant to Colletotrichum lagenarium infection.
- Taxon
- cucumber
Cucumis sativuse0 - Treatment
- growing the seedlings in the presence of dichloroisonicotinic acid (DCIA)e1
- Interactor
- Colletotrichum lagenariume1pathogen
- Outcome
- resistant to infectione1
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Segments from dark-grown cucumber (Cucumis sativus L.) hypocotyls”
e1“The segments were rendered resistant to infection by Colletotrichum lagenarium either by growing the seedlings in the presence of dichloroisonicotinic acid (DCIA)”
Claim · model-written summary
Resistance of cucumber hypocotyl segments to Colletotrichum lagenarium is mainly due to inhibited fungal penetration into epidermal cells.
- Taxon
- cucumberCucumis sativuse0
- Organ / stage
- epidermal cellse2
- Interactor
- Colletotrichum lagenariume1pathogen
- Outcome
- inhibition of fungal penetratione2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Segments from dark-grown cucumber (Cucumis sativus L.) hypocotyls”
e1“Colletotrichum lagenarium”
e2“This resistance appears to be due mainly to inhibition of fungal penetration into epidermal cells”
Claim · model-written summary
Fungal infection increased phenolic deposition at attempted penetration in resistant cucumber segments.
- Taxon
- cucumberCucumis sativuse0
- Organ / stage
- epidermal cell walle4
- Interactor
- Colletotrichum lagenariume1pathogen
- Outcome
- deposition of phenolicse3
- Direction
- increasede3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Segments from dark-grown cucumber (Cucumis sativus L.) hypocotyls”
e1“Colletotrichum lagenarium”
e3“In the resistant hypocotyl segments, the fungus induced, at the time of attempted penetration, an increased deposition of phenolics”
e4“These phenolics were located mainly in the epidermal cell wall around and in the emerging papillae below appressoria”
Claim · model-written summary
Pretreatment with DCIA, salicylic acid or 5-chlorosalicylic acid induced little chitinase activity in cucumber segments.
- Taxon
- cucumberCucumis sativuse0
- Treatment
- Pretreatment with DCIA, SA, and 5CSAe5
- Outcome
- chitinase activitye5
- Direction
- lowerinferrede5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Segments from dark-grown cucumber (Cucumis sativus L.) hypocotyls”
e5“Pretreatment with DCIA, SA, and 5CSA induced little chitinase activity, but this activity greatly increased in resistant tissues upon subsequent infection”
Claim · model-written summary
Chitinase activity greatly increased in resistant cucumber tissues upon subsequent Colletotrichum lagenarium infection.
- Taxon
- cucumberCucumis sativuse0
- Organ / stage
- resistant tissuese5
- Treatment
- subsequent infectione5
- Interactor
- Colletotrichum lagenariume1pathogen
- Outcome
- chitinase activitye5
- Direction
- greatly increasede5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Segments from dark-grown cucumber (Cucumis sativus L.) hypocotyls”
e5“Pretreatment with DCIA, SA, and 5CSA induced little chitinase activity, but this activity greatly increased in resistant tissues upon subsequent infection”
e1“Colletotrichum lagenarium”
Claim · model-written summary
Resistance is associated with an improved perception of the pathogen stimulus, enhancing induction of diverse defense reactions.
- Taxon
- cucumberCucumis sativuse0
- Outcome
- resistancee7
- Qualifier
- an improved perception of the pathogen stimuluse7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Segments from dark-grown cucumber (Cucumis sativus L.) hypocotyls”
e7“These observations indicate that resistance is associated with an improved perception of the pathogen stimulus resulting in the enhanced induction of diverse defense reactions”
Claim · model-written summary
Pretreated and split cucumber segments incubated with chitosan fragments showed enhanced deposition of cell wall phenolics.
- Taxon
- cucumberCucumis sativuse0
- Treatment
- chitosan fragmentse1
- Outcome
- deposition of cell wall phenolicse1
- Direction
- enhancede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Segments from dark-grown cucumber (Cucumis sativus L.) hypocotyls”
e1“When the cut segments were pretreated with DCIA, SA, or 5CSA and then split and incubated with chitosan fragments, the deposition of cell wall phenolics was also enhanced”
Claim · model-written summary
Pretreated and split cucumber segments showed an increase in elicitor-induced rapid production of activated oxygen species.
- Taxon
- cucumberCucumis sativuse0
- Treatment
- elicitor preparation from Phytophthora megasperma f. sp. Glyae1
- Interactor
- Phytophthora megasperma
Phytophthora megaspermae1pathogen - Outcome
- rapid production of activated oxygen speciese1
- Direction
- an increasee1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Segments from dark-grown cucumber (Cucumis sativus L.) hypocotyls”
e1“These pretreated and split segments also exhibited an increase in the rapid production of activated oxygen species induced by an elicitor preparation from Phytophthora megasperma f. sp. Glya”
Claim · model-written summary
Methyl jasmonate did not induce resistance of cucumber segments to Colletotrichum lagenarium.
- Taxon
- cucumberCucumis sativuse0
- Treatment
- methyl jasmonatee1
- Outcome
- resistancee1
- Direction
- no_changeinferrede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Segments from dark-grown cucumber (Cucumis sativus L.) hypocotyls”
e1“Pretreatment of the segments with methyl jasmonate neither induced resistance nor enhanced induction of cell wall phenolics upon fungal infection”
Claim · model-written summary
Methyl jasmonate did not enhance cell wall phenolics induced by fungal infection in cucumber segments.
- Taxon
- cucumberCucumis sativuse0
- Treatment
- methyl jasmonatee1
- Outcome
- cell wall phenolicse1
- Direction
- no_changeinferrede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Segments from dark-grown cucumber (Cucumis sativus L.) hypocotyls”
e1“Pretreatment of the segments with methyl jasmonate neither induced resistance nor enhanced induction of cell wall phenolics upon fungal infection”
Claim · model-written summary
Methyl jasmonate-pretreated split segments showed some increase in chitosan-induced cell wall phenolics.
- Taxon
- cucumberCucumis sativuse0
- Treatment
- methyl jasmonatee1
- Outcome
- chitosan-induced cell wall phenolicse2
- Direction
- some increasee2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Segments from dark-grown cucumber (Cucumis sativus L.) hypocotyls”
e1“Pretreatment of the segments with methyl jasmonate neither induced resistance nor enhanced induction of cell wall phenolics upon fungal infection”
e2“we observed in the corresponding split segments some increase in chitosan-induced cell wall phenolics and in elicitor-induced rapid production of activated oxygen species”
Claim · model-written summary
Methyl jasmonate-pretreated split segments showed some increase in elicitor-induced rapid production of activated oxygen species.
- Taxon
- cucumberCucumis sativuse0
- Treatment
- methyl jasmonatee1
- Outcome
- elicitor-induced rapid production of activated oxygen speciese2
- Direction
- some increasee2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Segments from dark-grown cucumber (Cucumis sativus L.) hypocotyls”
e1“Pretreatment of the segments with methyl jasmonate neither induced resistance nor enhanced induction of cell wall phenolics upon fungal infection”
e2“we observed in the corresponding split segments some increase in chitosan-induced cell wall phenolics and in elicitor-induced rapid production of activated oxygen species”
The same questions in other papers
(-)-methyl jasmonate · yield · Cucumis sativus (cucumber)Results agree
2 papers in the same direction as this paper
- positive
- positive
infection · physiology: antioxidant enzymes · Cucumis sativus (cucumber)Positive and negative results
3 papers in the same direction as this paper · 3 in the opposite direction
- negative
- no effect
- negative
3 papers more in this group
See all 7 papers →resistance inducer · yield · Cucumis sativus (cucumber)Results agree
1 paper in the same direction as this paper
- positive
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.