Abstract
In tobacco (Nicotiana tabacum L. cv Samsun NN), three distinct enzymes account for ortho-diphenol-O-methyltransferase (OMT) activity. OMT I is the major enzyme of healthy leaves, whereas enzymes OMT II and III are preferentially induced during the hypersensitive reaction to tobacco mosaic virus (TMV). Using an anti-OMT III antiserum, we isolated a partial OMT III cDNA clone by immunoscreening an expression library made from mRNA of TMV-infected tobacco leaves. Using this OMT III clone as a probe, we isolated a full-length clone with a deduced amino acid sequence encompassing all of the sequences obtained by Edman degradation of both purified proteins II and III. Thus, OMT II and III of tobacco are likely to be encoded by the same genes and to arise from different posttranslational modifications. Sequence analysis showed that this OMT clone represents a new class of OMT enzymes (class II) with a low level of similarity (53-58%) to OMTs cloned previously from other dicotyledonous plants. Southern analysis indicated that a small family of class II OMT genes inherited from ancestors related to Nicotiana sylvestris and Nicotiana tomentosiformis occurs in the tobacco genome. RNA blot analysis demonstrated that class II OMT genes, unlike class I OMT genes, are not expressed at a high constitutive level in lignified tissues of tobacco. Class II OMT transcripts were found to accumulate in tobacco leaves infected with TMV or treated with megaspermin, a proteinaceous elicitor from Phytophthora megasperma, but not in leaves treated with salicylic acid, a molecule known to trigger many defense genes. In TMV-infected or elicitor-treated tissues, a marked increase in catechol-methylating activity accompanied the accumulation of class II OMT gene products.
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Claims 13
Claim · model-written summary
Three enzymes account for tobacco OMT activity.
- Taxon
- tobacco
Nicotiana tabacume0 - Gene
- ortho-diphenol-O-methyltransferasee0
- Outcome
- three distinct enzymese0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In tobacco (Nicotiana tabacum L. cv Samsun NN), three distinct enzymes account for ortho-diphenol-O-methyltransferase (OMT) activity.”
Claim · model-written summary
OMT I predominated in healthy leaves.
- Taxon
- tobaccoNicotiana tabacumt0
- Gene
- OMT Ie0
- Outcome
- major enzyme of healthy leavese0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“OMT I is the major enzyme of healthy leaves”
t0“Molecular Cloning and Expression of a New Class of Ortho-Diphenol-O-Methyltransferases Induced in Tobacco (Nicotiana tabacum L.) Leaves by Infection or Elicitor Treatment”
Claim · model-written summary
OMT II and III were preferentially induced during the tobacco mosaic virus hypersensitive reaction.
- Taxon
- tobaccoNicotiana tabacumt0
- Interactor
- tobacco mosaic virus
Tobacco mosaic viruse0pathogen - Gene
- OMT II and IIIe0
- Outcome
- preferentially inducede0
- Direction
- inducede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“enzymes OMT II and III are preferentially induced during the hypersensitive reaction to tobacco mosaic virus (TMV)”
t0“Molecular Cloning and Expression of a New Class of Ortho-Diphenol-O-Methyltransferases Induced in Tobacco (Nicotiana tabacum L.) Leaves by Infection or Elicitor Treatment”
Claim · model-written summary
A partial OMT III cDNA clone was isolated.
- Taxon
- tobaccoNicotiana tabacume0
- Gene
- OMT IIIe0
- Outcome
- a partial OMT III cDNA clonee0
Not reportedComparatorValue
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“we isolated a partial OMT III cDNA clone by immunoscreening an expression library made from mRNA of TMV-infected tobacco leaves”
Claim · model-written summary
A full-length OMT clone encoded all sequenced portions of purified OMT II and III.
- Taxon
- tobaccoNicotiana tabacumt0
- Gene
- proteins II and IIIe0
- Outcome
- a full-length clone with a deduced amino acid sequence encompassing all of the sequencese0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“we isolated a full-length clone with a deduced amino acid sequence encompassing all of the sequences obtained by Edman degradation of both purified proteins II and III”
t0“Molecular Cloning and Expression of a New Class of Ortho-Diphenol-O-Methyltransferases Induced in Tobacco (Nicotiana tabacum L.) Leaves by Infection or Elicitor Treatment”
Claim · model-written summary
OMT II and III likely arise from the same genes via different posttranslational modifications.
- Taxon
- tobaccoNicotiana tabacume0
- Gene
- OMT II and IIIe0
- Outcome
- encoded by the same genese0
- Qualifier
- different posttranslational modificationse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“OMT II and III of tobacco are likely to be encoded by the same genes and to arise from different posttranslational modifications”
Claim · model-written summary
The cloned OMT represents a new class II enzyme with 53-58% similarity to previously cloned dicot OMTs.
- Taxon
- tobaccoNicotiana tabacumt0
- Gene
- OMTe0
- Outcome
- similaritye0
- Direction
- lowe0
- Value
- 53-58%e0
- Comparator
- OMTs cloned previously from other dicotyledonous plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“this OMT clone represents a new class of OMT enzymes (class II) with a low level of similarity (53-58%) to OMTs cloned previously from other dicotyledonous plants”
t0“Molecular Cloning and Expression of a New Class of Ortho-Diphenol-O-Methyltransferases Induced in Tobacco (Nicotiana tabacum L.) Leaves by Infection or Elicitor Treatment”
Claim · model-written summary
A small class II OMT gene family occurs in the tobacco genome and derives from ancestors related to two Nicotiana species.
- Taxon
- tobaccoNicotiana tabacume0
- Gene
- class II OMT genese0
- Outcome
- a small family of class II OMT genese0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a small family of class II OMT genes inherited from ancestors related to Nicotiana sylvestris and Nicotiana tomentosiformis occurs in the tobacco genome”
Claim · model-written summary
Class II OMT genes lack high constitutive expression in lignified tobacco tissue relative to class I genes.
- Taxon
- tobaccoNicotiana tabacume0
- Gene
- class II OMT genese0
- Outcome
- expressed at a high constitutive levele0
- Direction
- not expressede0
- Comparator
- class I OMT genese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“class II OMT genes, unlike class I OMT genes, are not expressed at a high constitutive level in lignified tissues of tobacco”
Claim · model-written summary
TMV infection increased class II OMT transcript accumulation.
- Taxon
- tobaccoNicotiana tabacume0
- Treatment
- infected with TMVe0
- Interactor
- TMVTobacco mosaic viruse0pathogen
- Gene
- Class II OMT transcriptse0
- Outcome
- Class II OMT transcriptse0
- Direction
- accumulatee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Class II OMT transcripts were found to accumulate in tobacco leaves infected with TMV or treated with megaspermin”
Claim · model-written summary
Megaspermin treatment increased class II OMT transcript accumulation.
- Taxon
- tobaccoNicotiana tabacume0
- Treatment
- treated with megaspermine0
- Gene
- Class II OMT transcriptse0
- Outcome
- Class II OMT transcriptse0
- Direction
- accumulatee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Class II OMT transcripts were found to accumulate in tobacco leaves infected with TMV or treated with megaspermin, a proteinaceous elicitor from Phytophthora megasperma”
Claim · model-written summary
Salicylic acid treatment did not induce class II OMT transcripts.
- Taxon
- tobaccoNicotiana tabacumt0
- Treatment
- treated with salicylic acide0
- Gene
- class II OMTt1
- Outcome
- class II OMTt1
- Direction
- note0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“but not in leaves treated with salicylic acid”
t0“Molecular Cloning and Expression of a New Class of Ortho-Diphenol-O-Methyltransferases Induced in Tobacco (Nicotiana tabacum L.) Leaves by Infection or Elicitor Treatment”
t1“Class II OMT transcripts were found to accumulate”
Claim · model-written summary
TMV infection or elicitor treatment increased catechol-methylating activity alongside class II OMT products.
- Taxon
- tobaccoNicotiana tabacumt0
- Treatment
- TMV-infected or elicitor-treatede0
- Outcome
- catechol-methylating activitye0
- Direction
- increasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In TMV-infected or elicitor-treated tissues, a marked increase in catechol-methylating activity accompanied the accumulation of class II OMT gene products.”
t0“Molecular Cloning and Expression of a New Class of Ortho-Diphenol-O-Methyltransferases Induced in Tobacco (Nicotiana tabacum L.) Leaves by Infection or Elicitor Treatment”
The same questions in other papers
salicylic acid · molecular: metabolites · Nicotiana tabacum (tobacco)Positive and negative results
5 papers in the same direction as this paper · 9 in the opposite direction
- positive
- positive
- positive
11 papers more in this group
See all 15 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.