Abstract
Through a biochemical and a genetic approach, we have identified several plant genes encoding methylthioribose (MTR) kinase, an enzyme involved in recycling of methionine through the methylthioadenosine (MTA) cycle. OsMTK1, an MTR kinase from rice (Oryza sativa), is 48.6 kD in size and shows cooperative kinetics with a V(max) of 4.9 pmol/min and a K0.5 of 16.8 microm. MTR kinase genes are the first genes to be identified from the MTA cycle in plants. Insertional mutagenesis of the unique AtMTK gene in Arabidopsis (Arabidopsis thaliana) resulted in an inability of plants to grow on MTA as a supplemental sulfur source. MTK knock-out plants were not impaired in growth under standard conditions, indicating that the MTA cycle is a nonessential metabolic pathway in Arabidopsis when sulfur levels are replete. In rice, OsMTK genes were strongly up-regulated in shoots and roots when plants were exposed to sulfur starvation. Gene expression was largely unaffected by lack of nitrogen or iron in the nutrient solution, indicating that OsMTK regulation was linked specifically to sulfur metabolism.
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Claims 9
Claim · model-written summary
Several plant genes encoding MTR kinase were identified.
Not reportedDirection
Verbatim
e0“we have identified several plant genes encoding methylthioribose (MTR) kinase”
Claim · model-written summary
Rice OsMTK1 has a size of 48.6 kD.
- Taxon
- rice (Oryza sativa)
Oryza sativae0 - Gene
- OsMTK1e0
- Outcome
- sizee0
- Value
- 48.6 kDe0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“OsMTK1, an MTR kinase from rice (Oryza sativa), is 48.6 kD in size”
Claim · model-written summary
Rice OsMTK1 showed cooperative kinetics with V(max) 4.9 pmol/min.
- Taxon
- rice (Oryza sativa)Oryza sativae0
- Gene
- OsMTK1e0
- Outcome
- V(max)e0
- Value
- 4.9 pmol/mine0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“OsMTK1, an MTR kinase from rice (Oryza sativa), is 48.6 kD in size and shows cooperative kinetics with a V(max) of 4.9 pmol/min and a K0.5 of 16.8 microm.”
Claim · model-written summary
Rice OsMTK1 had K0.5 of 16.8 microm.
- Taxon
- rice (Oryza sativa)Oryza sativae0
- Gene
- OsMTK1e0
- Outcome
- K0.5e0
- Value
- 16.8 microme0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“OsMTK1, an MTR kinase from rice (Oryza sativa), is 48.6 kD in size and shows cooperative kinetics with a V(max) of 4.9 pmol/min and a K0.5 of 16.8 microm.”
Claim · model-written summary
AtMTK insertional mutation prevented Arabidopsis growth on MTA as supplemental sulfur.
- Taxon
- Arabidopsis (Arabidopsis thaliana)
Arabidopsis thalianae0 - Treatment
- Insertional mutagenesise0
- Gene
- AtMTKe0
- Outcome
- inability of plants to grow on MTA as a supplemental sulfur sourcee0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Insertional mutagenesis of the unique AtMTK gene in Arabidopsis (Arabidopsis thaliana) resulted in an inability of plants to grow on MTA as a supplemental sulfur source.”
Claim · model-written summary
MTK knock-out plants grew without impairment under standard conditions.
- Taxon
- plantsViridiplantaee0
- Material
- MTK knock-out plantse0
- Outcome
- growthe0
- Direction
- not impairede0
Verbatim
e0“MTK knock-out plants were not impaired in growth under standard conditions”
Claim · model-written summary
Sulfur starvation strongly up-regulated rice OsMTK genes in shoots and roots.
- Taxon
- riceOryza sativae0
- Organ / stage
- shoots and rootse0
- Treatment
- sulfur starvatione0
- Gene
- OsMTKe0
- Outcome
- OsMTK genese0
- Direction
- up-regulatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In rice, OsMTK genes were strongly up-regulated in shoots and roots when plants were exposed to sulfur starvation.”
Claim · model-written summary
Nitrogen deficiency largely left rice OsMTK gene expression unaffected.
- Taxon
- riceOryza sativae1
- Treatment
- lack of nitrogene0
- Gene
- OsMTKe1
- Outcome
- Gene expressione0
- Direction
- largely unaffectede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Gene expression was largely unaffected by lack of nitrogen or iron in the nutrient solution”
e1“In rice, OsMTK genes were strongly up-regulated in shoots and roots when plants were exposed to sulfur starvation.”
Claim · model-written summary
Iron deficiency largely left rice OsMTK gene expression unaffected.
- Taxon
- riceOryza sativae1
- Treatment
- irone0
- Gene
- OsMTKe1
- Outcome
- Gene expressione0
- Direction
- largely unaffectede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Gene expression was largely unaffected by lack of nitrogen or iron in the nutrient solution”
e1“In rice, OsMTK genes were strongly up-regulated in shoots and roots when plants were exposed to sulfur starvation.”
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This paper is about lacking the nutrient, so it counts the other way round here.
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See all 45 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.