Abstract
Rhizobial Nod factors (NFs) function as nodulation signals that trigger symbiotic responses of leguminous host plants. NFs consist of a chitin oligomer backbone carrying a fatty acid at the non-reducing end. Depending on the rhizobial strain, NFs carry additional substituents, which may determine host specificity. Transgenic suspension-cultured soybean (Glycine max [L.] Merr.) cells expressing aequorin have been used to record cytosolic [Ca(2+)] changes upon treatment with purified NFs and chitin fragments. Both compounds elicited an increase of cytosolic [Ca(2+)] at nanomolar concentrations. The shape and amplitude of cytosolic [Ca(2+)] changes was similar to the response elicited by un-derivatized chitin oligomers. Cells challenged first with NFs did not respond to a subsequent treatment with chitin oligomers and vice versa. Dose-response experiments showed that un-derivatized chitin oligomers were more active compared with NFs. The capacity of NFs to elicit the calcium response depended on their structure. The presence of reducing end substituents in methylfucosylated NFs from Rhizobium sp. NGR234 and the O-acetyl group at the non-reducing end in NFs from Sinorhizobium meliloti attenuated the activity to cause the calcium changes. The sulfate group in NFs from Rhizobium tropici did not affect the elicitor activity. Pentameric S. meliloti NFs were more active than tetrameric molecules, whereas trimeric or dimeric degradation products were inactive. Substituents in NFs may have the function to avoid stimulation of defense reactions mediated by the perception system for chitin oligomers.
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 12
Claim · model-written summary
Nod factors elicited increased cytosolic calcium at nanomolar concentrations.
- Taxon
- Soybean
Glycine maxt0 - Treatment
- NFse1
- Outcome
- cytosolic [Ca(2+)]e0
- Direction
- increasee0
- Qualifier
- nanomolar concentrationse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Both compounds elicited an increase of cytosolic [Ca(2+)] at nanomolar concentrations.”
t0“Soybean”
e1“treatment with purified NFs and chitin fragments”
Claim · model-written summary
Chitin fragments elicited increased cytosolic calcium at nanomolar concentrations.
- Taxon
- SoybeanGlycine maxt0
- Treatment
- chitin fragmentse1
- Outcome
- cytosolic [Ca(2+)]e0
- Direction
- increasee0
- Qualifier
- nanomolar concentrationse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Both compounds elicited an increase of cytosolic [Ca(2+)] at nanomolar concentrations.”
t0“Soybean”
e1“treatment with purified NFs and chitin fragments”
Claim · model-written summary
Nod factors and un-derivatized chitin oligomers produced similar calcium-response shape and amplitude.
- Taxon
- SoybeanGlycine maxt0
- Outcome
- shape and amplitude of cytosolic [Ca(2+)] changese0
- Comparator
- un-derivatized chitin oligomerse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The shape and amplitude of cytosolic [Ca(2+)] changes was similar to the response elicited by un-derivatized chitin oligomers.”
t0“Soybean”
Claim · model-written summary
Prior Nod-factor challenge prevented a response to subsequent chitin oligomers.
- Taxon
- SoybeanGlycine maxt0
- Treatment
- challenged first with NFse0
- Outcome
- did not respond to a subsequent treatment with chitin oligomerse0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Cells challenged first with NFs did not respond to a subsequent treatment with chitin oligomers and vice versa.”
t0“Soybean”
Claim · model-written summary
Prior chitin-oligomer challenge prevented a response to subsequent Nod factors.
- Taxon
- SoybeanGlycine maxt0
- Treatment
- chitin oligomerse0
- Outcome
- vice versae0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Cells challenged first with NFs did not respond to a subsequent treatment with chitin oligomers and vice versa.”
t0“Soybean”
Claim · model-written summary
Un-derivatized chitin oligomers were more active than Nod factors.
- Taxon
- SoybeanGlycine maxt0
- Outcome
- more activee0
- Direction
- more activee0
- Comparator
- NFse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“un-derivatized chitin oligomers were more active compared with NFs”
t0“Soybean”
Claim · model-written summary
Reducing-end substituents in NGR234 Nod factors attenuated calcium elicitation.
- Taxon
- SoybeanGlycine maxt0
- Treatment
- reducing end substituents in methylfucosylated NFs from Rhizobium sp. NGR234e0
- Interactor
- Rhizobium sp. NGR234Sinorhizobium fredii NGR234e0symbiont
- Outcome
- activity to cause the calcium changese0
- Direction
- attenuatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The presence of reducing end substituents in methylfucosylated NFs from Rhizobium sp. NGR234 and the O-acetyl group at the non-reducing end in NFs from Sinorhizobium meliloti attenuated the activity to cause the calcium changes.”
t0“Soybean”
Claim · model-written summary
The O-acetyl group in S. meliloti Nod factors attenuated calcium elicitation.
- Taxon
- SoybeanGlycine maxt0
- Treatment
- O-acetyl group at the non-reducing end in NFs from Sinorhizobium melilotie0
- Interactor
- Sinorhizobium meliloti
Sinorhizobium melilotie0symbiont - Outcome
- activity to cause the calcium changese0
- Direction
- attenuatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The presence of reducing end substituents in methylfucosylated NFs from Rhizobium sp. NGR234 and the O-acetyl group at the non-reducing end in NFs from Sinorhizobium meliloti attenuated the activity to cause the calcium changes.”
t0“Soybean”
Claim · model-written summary
A sulfate group in R. tropici Nod factors did not alter elicitor activity.
- Taxon
- SoybeanGlycine maxt0
- Interactor
- Rhizobium tropici
Martinezella tropicie0symbiont - Outcome
- elicitor activitye0
- Direction
- did not affecte0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The sulfate group in NFs from Rhizobium tropici did not affect the elicitor activity.”
t0“Soybean”
Claim · model-written summary
Pentameric S. meliloti Nod factors were more active than tetramers.
- Taxon
- SoybeanGlycine maxt0
- Interactor
- S. melilotiSinorhizobium melilotie0symbiont
- Outcome
- more activee0
- Direction
- more activee0
- Comparator
- tetrameric moleculese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Pentameric S. meliloti NFs were more active than tetrameric molecules”
t0“Soybean”
Claim · model-written summary
Trimeric and dimeric degradation products were inactive.
- Taxon
- SoybeanGlycine maxt0
- Outcome
- were inactivee0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“trimeric or dimeric degradation products were inactive”
t0“Soybean”
Claim · model-written summary
Nod-factor substituents may avoid triggering chitin-perception defense reactions.
- Taxon
- SoybeanGlycine maxt0
- Outcome
- avoid stimulation of defense reactionse0
- Qualifier
- perception system for chitin oligomerse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Substituents in NFs may have the function to avoid stimulation of defense reactions mediated by the perception system for chitin oligomers.”
t0“Soybean”
The same questions in other papers
nodulation factor · molecular: metabolites · Glycine max (soybean)Positive and negative results
1 in the opposite direction
- positive
infection · molecular: metabolites · Glycine max (soybean)Positive and negative results
4 papers in the same direction as this paper · 12 in the opposite direction
- positive
- positive
- positive
13 papers more in this group
See all 17 papers →resistance inducer · nutrient: content · Glycine max (soybean)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.