Abstract
Nitric oxide (NO) generation by soybean (Glycine max var. ADM 4800) chloroplasts was studied as an endogenous product assessed by the electron paramagnetic resonance spin-trapping technique. Nitrite and l-arginine (Arg) are substrates for enzymatic activities considered to be the possible sources of NO in plants. Soybean chloroplasts showed a NO production of 3.2 +/- 0.2 nmol min(-1) mg(-1) protein in the presence of 1 mm NaNO(2). Inhibition of photosynthetic electron flow by 3-(3,4-dichlorophenyl)-1,1-dimethyl urea resulted in a lower rate (1.21 +/- 0.04 nmol min(-1) mg(-1) protein) of NO generation. Chloroplasts incubated with 1 mm Arg showed NO production of 0.76 +/- 0.04 nmol min(-1) mg(-1) protein that was not affected either by omission of Ca(2+) or by supplementation with Ca(2+) and calmodulin to the incubation medium. This production was inhibited when chloroplasts were incubated in the presence of NO synthase inhibitors N(omega)-nitro-l-Arg methyl ester hydrochloride and N(omega)-nitro-l-Arg. In vitro exposure of chloroplasts to an NO donor (250 mum S-nitrosoglutathione) decreased lipid radical content in membranes by 29%; however, incubation in the presence of 25 mum peroxynitrite (ONOO(-)) led to an increase in lipid-derived radicals (34%). The effect of ONOO(-) on protein oxidation was determined by western blotting, showing an increase in carbonyl content either in stroma or thylakoid proteins as compared to controls. Moreover, ONOO(-) treatment significantly affected both O(2) evolution and chlorophyll fluorescence in thylakoids. Data reported here suggest that NO is an endogenous metabolite in soybean chloroplasts and that reactive nitrogen species could exert either antioxidant or prooxidant effects on chloroplast macromolecules.
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Claims 9
Claim · model-written summary
Soybean chloroplasts produced NO at 3.2 +/- 0.2 nmol min(-1) mg(-1) protein with 1 mm nitrite.
- Taxon
- Soybean
Glycine maxe0 - Treatment
- 1 mm NaNO(2)e0
- Outcome
- NO productione0
- Value
- 3.2 +/- 0.2 nmol min(-1) mg(-1) proteine0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soybean chloroplasts showed a NO production of 3.2 +/- 0.2 nmol min(-1) mg(-1) protein in the presence of 1 mm NaNO(2)”
Claim · model-written summary
Inhibiting photosynthetic electron flow lowered chloroplast NO generation to 1.21 +/- 0.04 nmol min(-1) mg(-1) protein.
- Taxon
- soybeanGlycine maxt0
- Treatment
- 3-(3,4-dichlorophenyl)-1,1-dimethyl ureae0
- Outcome
- NO generatione0
- Direction
- lowere0
- Value
- 1.21 +/- 0.04 nmol min(-1) mg(-1) proteine0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Inhibition of photosynthetic electron flow by 3-(3,4-dichlorophenyl)-1,1-dimethyl urea resulted in a lower rate (1.21 +/- 0.04 nmol min(-1) mg(-1) protein) of NO generation”
t0“Nitric oxide (NO) generation by soybean (Glycine max var. ADM 4800)”
Claim · model-written summary
Arg incubation yielded 0.76 +/- 0.04 nmol min(-1) mg(-1) protein of chloroplast NO.
- Taxon
- soybeanGlycine maxt0
- Treatment
- 1 mm Arge0
- Outcome
- NO productione0
- Value
- 0.76 +/- 0.04 nmol min(-1) mg(-1) proteine0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Chloroplasts incubated with 1 mm Arg showed NO production of 0.76 +/- 0.04 nmol min(-1) mg(-1) protein”
t0“Nitric oxide (NO) generation by soybean (Glycine max var. ADM 4800)”
Claim · model-written summary
Changing calcium or calmodulin availability did not affect Arg-dependent NO production.
- Taxon
- soybeanGlycine maxt0
- Treatment
- omission of Ca(2+)e0
- Outcome
- NO productione1
- Direction
- not affectede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“that was not affected either by omission of Ca(2+) or by supplementation with Ca(2+) and calmodulin to the incubation medium”
t0“Nitric oxide (NO) generation by soybean (Glycine max var. ADM 4800)”
e1“NO production of 0.76 +/- 0.04 nmol min(-1) mg(-1) protein”
Claim · model-written summary
NO synthase inhibitors inhibited Arg-dependent chloroplast NO production.
- Taxon
- soybeanGlycine maxt0
- Treatment
- NO synthase inhibitors N(omega)-nitro-l-Arg methyl ester hydrochloride and N(omega)-nitro-l-Arge0
- Outcome
- productione0
- Direction
- inhibitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This production was inhibited when chloroplasts were incubated in the presence of NO synthase inhibitors N(omega)-nitro-l-Arg methyl ester hydrochloride and N(omega)-nitro-l-Arg”
t0“Nitric oxide (NO) generation by soybean (Glycine max var. ADM 4800)”
Claim · model-written summary
An NO donor reduced chloroplast membrane lipid radicals by 29%.
- Taxon
- soybeanGlycine maxt0
- Treatment
- 250 mum S-nitrosoglutathionee0
- Outcome
- lipid radical content in membranese0
- Direction
- decreasede0
- Value
- 29%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In vitro exposure of chloroplasts to an NO donor (250 mum S-nitrosoglutathione) decreased lipid radical content in membranes by 29%”
t0“Nitric oxide (NO) generation by soybean (Glycine max var. ADM 4800)”
Claim · model-written summary
Peroxynitrite increased chloroplast lipid-derived radicals by 34%.
- Taxon
- soybeanGlycine maxt0
- Treatment
- 25 mum peroxynitrite (ONOO(-))e0
- Outcome
- lipid-derived radicalse0
- Direction
- increasee0
- Value
- 34%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“incubation in the presence of 25 mum peroxynitrite (ONOO(-)) led to an increase in lipid-derived radicals (34%)”
t0“Nitric oxide (NO) generation by soybean (Glycine max var. ADM 4800)”
Claim · model-written summary
Peroxynitrite raised protein carbonyl content in stroma and thylakoids relative to controls.
- Taxon
- soybeanGlycine maxt0
- Treatment
- ONOO(-)e0
- Outcome
- carbonyl contente0
- Direction
- increasee0
- Comparator
- controlse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“ONOO(-) on protein oxidation was determined by western blotting, showing an increase in carbonyl content either in stroma or thylakoid proteins as compared to controls”
t0“Nitric oxide (NO) generation by soybean (Glycine max var. ADM 4800)”
Claim · model-written summary
Peroxynitrite significantly affected thylakoid oxygen evolution and chlorophyll fluorescence.
- Taxon
- soybeanGlycine maxt0
- Treatment
- ONOO(-) treatmente0
- Outcome
- O(2) evolution and chlorophyll fluorescencee0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“ONOO(-) treatment significantly affected both O(2) evolution and chlorophyll fluorescence in thylakoids”
t0“Nitric oxide (NO) generation by soybean (Glycine max var. ADM 4800)”
The same questions in other papers
S-nitrosoglutathione · molecular: metabolites · Glycine max (soybean)Positive and negative results
1 in the opposite direction
- no effect
peroxynitrite · molecular: metabolites · Glycine max (soybean)Results agree
1 paper in the same direction as this paper
- negative
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.