Abstract
The L-isoaspartyl protein methyltransferase (EC 2.1.1.77) has been proposed to be involved in the repair of spontaneously damaged proteins by facilitating the conversion of abnormal L-isoaspartyl residues to normal L-aspartyl residues. Based on the abundance of this enzyme in the seeds of a variety of plants and its unique substrate specificity, it has been hypothesized that it functions to prevent the accumulation of abnormal aspartyl residues in the proteins of aging seeds that can limit the viability of the embryo or its chances for germination. In this work, we show that the expression of the L-isoaspartyl methyltransferase is under developmental regulation in the winter wheat, Triticum aestivum. Methyltransferase mRNA and active enzyme are first detected in seeds during the late stages (III-IV) of caryopsis development. As mature seeds germinate, methyltransferase mRNA levels decline and are nearly undetectable by 72 h post-imbibition. Enzyme activity remains constant for 24 h post-imbibition and then decreases rapidly following the reduction of its corresponding mRNA. Methyltransferase activity is very low or undetectable in wheat seedlings, including leaf and root tissues. We show, however, that the L-isoaspartyl methyltransferase can be induced in vegetative tissues in response to hormone treatment and environmental stress. Abscisic acid, a phytohormone involved in seed development and desiccation tolerance, induces both methyltransferase mRNA and enzyme activity in 4-day-old wheat seedlings. Dehydration and salt stress also induce its transcription and enzymatic activity in seedlings. The ability of a plant to regulate methyltransferase activity in its seeds and vegetative tissues in response to desiccation, aging, and environmental stress may allow the plant to efficiently repair protein damage associated with these physiological changes.
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Claims 8
Claim · model-written summary
Methyltransferase mRNA and enzyme first appeared at late caryopsis development.
- Taxon
- winter wheat
Triticum aestivume0 - Organ / stage
- seedse1
- Gene
- L-isoaspartyl methyltransferasee0
- Outcome
- Methyltransferase mRNA and active enzymee1
- Qualifier
- late stages (III-IV)e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In this work, we show that the expression of the L-isoaspartyl methyltransferase is under developmental regulation in the winter wheat, Triticum aestivum.”
e1“Methyltransferase mRNA and active enzyme are first detected in seeds during the late stages (III-IV) of caryopsis development.”
Claim · model-written summary
Methyltransferase mRNA declined during germination and was nearly undetectable at 72 h.
- Taxon
- winter wheatTriticum aestivume0
- Organ / stage
- mature seedse1
- Gene
- L-isoaspartyl methyltransferasee0
- Outcome
- methyltransferase mRNA levelse1
- Direction
- declinee1
- Value
- 72 he1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In this work, we show that the expression of the L-isoaspartyl methyltransferase is under developmental regulation in the winter wheat, Triticum aestivum.”
e1“As mature seeds germinate, methyltransferase mRNA levels decline and are nearly undetectable by 72 h post-imbibition.”
Claim · model-written summary
Enzyme activity remained constant for 24 h after imbibition.
- Taxon
- winter wheatTriticum aestivume0
- Gene
- L-isoaspartyl methyltransferasee0
- Outcome
- Enzyme activitye1
- Direction
- remains constante1
- Value
- 24 he1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In this work, we show that the expression of the L-isoaspartyl methyltransferase is under developmental regulation in the winter wheat, Triticum aestivum.”
e1“Enzyme activity remains constant for 24 h post-imbibition and then decreases rapidly following the reduction of its corresponding mRNA.”
Claim · model-written summary
Enzyme activity then decreased rapidly.
- Taxon
- winter wheatTriticum aestivume0
- Gene
- L-isoaspartyl methyltransferasee0
- Outcome
- Enzyme activitye1
- Direction
- decreases rapidlye1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In this work, we show that the expression of the L-isoaspartyl methyltransferase is under developmental regulation in the winter wheat, Triticum aestivum.”
e1“Enzyme activity remains constant for 24 h post-imbibition and then decreases rapidly following the reduction of its corresponding mRNA.”
Claim · model-written summary
Methyltransferase activity was very low or undetectable in seedling leaves and roots.
- Taxon
- wheatTriticum aestivume1
- Organ / stage
- leaf and root tissuese1
- Gene
- L-isoaspartyl methyltransferasee0
- Outcome
- Methyltransferase activitye1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In this work, we show that the expression of the L-isoaspartyl methyltransferase is under developmental regulation in the winter wheat, Triticum aestivum.”
e1“Methyltransferase activity is very low or undetectable in wheat seedlings, including leaf and root tissues.”
Claim · model-written summary
Abscisic acid induced methyltransferase transcription and enzyme activity in seedlings.
- Taxon
- winter wheatTriticum aestivume0
- Organ / stage
- seedlingse1
- Treatment
- Abscisic acide1
- Gene
- L-isoaspartyl methyltransferasee0
- Outcome
- methyltransferase mRNA and enzyme activitye1
- Direction
- inducese1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In this work, we show that the expression of the L-isoaspartyl methyltransferase is under developmental regulation in the winter wheat, Triticum aestivum.”
e1“Abscisic acid, a phytohormone involved in seed development and desiccation tolerance, induces both methyltransferase mRNA and enzyme activity in 4-day-old wheat seedlings.”
Claim · model-written summary
Dehydration induced methyltransferase transcription and enzyme activity in seedlings.
- Taxon
- winter wheatTriticum aestivume0
- Organ / stage
- seedlingse1
- Treatment
- Dehydratione1
- Gene
- L-isoaspartyl methyltransferasee0
- Outcome
- transcription and enzymatic activitye1
- Direction
- inducee1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In this work, we show that the expression of the L-isoaspartyl methyltransferase is under developmental regulation in the winter wheat, Triticum aestivum.”
e1“Dehydration and salt stress also induce its transcription and enzymatic activity in seedlings.”
Claim · model-written summary
salt stress induced methyltransferase transcription and enzyme activity in seedlings.
- Taxon
- winter wheatTriticum aestivume0
- Organ / stage
- seedlingse1
- Treatment
- salt stresse1
- Gene
- L-isoaspartyl methyltransferasee0
- Outcome
- transcription and enzymatic activitye1
- Direction
- inducee1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In this work, we show that the expression of the L-isoaspartyl methyltransferase is under developmental regulation in the winter wheat, Triticum aestivum.”
e1“Dehydration and salt stress also induce its transcription and enzymatic activity in seedlings.”
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See all 98 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.