Abstract
The relationship of phototransformable protochlorophyll-(ide) to photoinactive protochlorophyll(ide) has been studied in the primary leaves of 7- to 9-day-old dark-grown bean (Phaseolus vulgaris L. var. Red Kidney) seedlings. Subjecting the leaves to an atmosphere of H(2)S causes an immediate loss of phototransformable protochlorophyll(ide)(650) and a simultaneous increase in photoinactive protochlorophyll(ide)(633). When such leaves are returned to air or N(2), the absorbance at 650 nm increases, whereas the absorbance at 633 nm decreases and photoactivity is restored. The reversion of protochlorophyll-(ide)(633) to protochlorophyll(ide)(650) is one-half complete in 3 minutes at 22 C in 8-day-old leaves. Ninety-five per cent recovery of protochlorophyll(ide)(650) is obtained when exposure to H(2)S is less than 3 minutes in duration; longer periods reduce the reversion capacity proportionately. The leaves are relatively undamaged by brief exposures to H(2)S, as judged by electron microscopy and by their ability to synthesize chlorophyll under continuous illumination. Hydrogen sulfide has no immediate effect upon the absorption properties of a partially purified preparation of the protochlorophyll(ide) holochrome, an etioplast suspension, or leaves subjected to freezing and thawing. Compounds such as HCN and HN(3) cause an irreversible conversion of protochlorophyll(ide)(650) to protochlorophyll(ide)(633) with total loss of photoactivity. Sulfhydryl agents, such as beta-mercaptoethanol and cysteine, cause a slow, irreversible transformation of the photoactive pigment to the photoinactive form and inhibit the ability of the leaves to synthesize chlorophyll under continuous illumination. The results obtained suggest that H(2)S may alter the interaction between the source of hydrogens on the protein moiety of the holochrome and the chromophore in vivo by reducing a disulfide bond in the protein, thereby causing a reversible conformational change in the complex.
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Claims 14
Claim · model-written summary
H2S exposure causes an immediate loss of phototransformable protochlorophyll(ide)(650) in bean leaves.
- Taxon
- Phaseolus vulgaris
Phaseolus vulgarise0 - Treatment
- Subjecting the leaves to an atmosphere of H(2)Se1
- Outcome
- phototransformable protochlorophyll(ide)(650)e1
- Direction
- losse1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“dark-grown bean (Phaseolus vulgaris L. var. Red Kidney) seedlings”
e1“Subjecting the leaves to an atmosphere of H(2)S causes an immediate loss of phototransformable protochlorophyll(ide)(650) and a simultaneous increase in photoinactive protochlorophyll(ide)(633)”
Claim · model-written summary
H2S exposure increases photoinactive protochlorophyll(ide)(633) in bean leaves.
- Taxon
- Phaseolus vulgarisPhaseolus vulgarise0
- Treatment
- Subjecting the leaves to an atmosphere of H(2)Se1
- Outcome
- photoinactive protochlorophyll(ide)(633)e1
- Direction
- increasee1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“dark-grown bean (Phaseolus vulgaris L. var. Red Kidney) seedlings”
e1“Subjecting the leaves to an atmosphere of H(2)S causes an immediate loss of phototransformable protochlorophyll(ide)(650) and a simultaneous increase in photoinactive protochlorophyll(ide)(633)”
Claim · model-written summary
Returning H2S-treated bean leaves to air or N2 increases absorbance at 650 nm.
- Taxon
- Phaseolus vulgarisPhaseolus vulgarise0
- Treatment
- returned to air or N(2)e1
- Outcome
- absorbance at 650 nme1
- Direction
- increasese1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“dark-grown bean (Phaseolus vulgaris L. var. Red Kidney) seedlings”
e1“When such leaves are returned to air or N(2), the absorbance at 650 nm increases, whereas the absorbance at 633 nm decreases and photoactivity is restored”
Claim · model-written summary
Returning H2S-treated bean leaves to air or N2 decreases absorbance at 633 nm.
- Taxon
- Phaseolus vulgarisPhaseolus vulgarise0
- Treatment
- returned to air or N(2)e1
- Outcome
- absorbance at 633 nme1
- Direction
- decreasese1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“dark-grown bean (Phaseolus vulgaris L. var. Red Kidney) seedlings”
e1“When such leaves are returned to air or N(2), the absorbance at 650 nm increases, whereas the absorbance at 633 nm decreases and photoactivity is restored”
Claim · model-written summary
Returning H2S-treated bean leaves to air or N2 restores photoactivity.
- Taxon
- Phaseolus vulgarisPhaseolus vulgarise0
- Treatment
- returned to air or N(2)e1
- Outcome
- photoactivity is restorede1
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“dark-grown bean (Phaseolus vulgaris L. var. Red Kidney) seedlings”
e1“When such leaves are returned to air or N(2), the absorbance at 650 nm increases, whereas the absorbance at 633 nm decreases and photoactivity is restored”
Claim · model-written summary
In 8-day-old bean leaves the reversion of protochlorophyll(ide)(633) to protochlorophyll(ide)(650) is one-half complete in 3 minutes at 22 C.
- Taxon
- Phaseolus vulgarisPhaseolus vulgarise0
- Outcome
- reversion of protochlorophyll-(ide)(633) to protochlorophyll(ide)(650)e1
- Value
- 3 minutese1
- Qualifier
- one-half complete in 3 minutes at 22 C in 8-day-old leavese1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“dark-grown bean (Phaseolus vulgaris L. var. Red Kidney) seedlings”
e1“The reversion of protochlorophyll-(ide)(633) to protochlorophyll(ide)(650) is one-half complete in 3 minutes at 22 C in 8-day-old leaves”
Claim · model-written summary
About 95% of protochlorophyll(ide)(650) is recovered when H2S exposure is less than 3 minutes.
- Taxon
- Phaseolus vulgarisPhaseolus vulgarise0
- Treatment
- exposure to H(2)Se1
- Outcome
- recovery of protochlorophyll(ide)(650)e1
- Value
- Ninety-five per cente1
- Qualifier
- less than 3 minutes in duratione1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“dark-grown bean (Phaseolus vulgaris L. var. Red Kidney) seedlings”
e1“Ninety-five per cent recovery of protochlorophyll(ide)(650) is obtained when exposure to H(2)S is less than 3 minutes in duration”
Claim · model-written summary
Longer H2S exposure periods reduce the reversion capacity of bean leaves proportionately.
- Taxon
- Phaseolus vulgarisPhaseolus vulgarise0
- Treatment
- longer periodse1
- Outcome
- reversion capacitye1
- Direction
- reducee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“dark-grown bean (Phaseolus vulgaris L. var. Red Kidney) seedlings”
e1“longer periods reduce the reversion capacity proportionately”
Claim · model-written summary
Brief H2S exposures leave bean leaves relatively undamaged, judged by electron microscopy and chlorophyll synthesis under illumination.
- Taxon
- Phaseolus vulgarisPhaseolus vulgarise0
- Treatment
- brief exposures to H(2)Se1
- Outcome
- relatively undamagede1
- Qualifier
- as judged by electron microscopye1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“dark-grown bean (Phaseolus vulgaris L. var. Red Kidney) seedlings”
e1“The leaves are relatively undamaged by brief exposures to H(2)S, as judged by electron microscopy and by their ability to synthesize chlorophyll under continuous illumination”
Claim · model-written summary
H2S has no immediate effect on the absorption properties of a partially purified protochlorophyll(ide) holochrome preparation, an etioplast suspension, or freeze-thawed leaves.
- Taxon
- Phaseolus vulgarisPhaseolus vulgarise0
- Treatment
- Hydrogen sulfidee1
- Outcome
- absorption propertiese1
- Qualifier
- a partially purified preparation of the protochlorophyll(ide) holochromee1
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“dark-grown bean (Phaseolus vulgaris L. var. Red Kidney) seedlings”
e1“Hydrogen sulfide has no immediate effect upon the absorption properties of a partially purified preparation of the protochlorophyll(ide) holochrome, an etioplast suspension, or leaves subjected to freezing and thawing”
Claim · model-written summary
HCN and HN3 cause an irreversible conversion of protochlorophyll(ide)(650) to protochlorophyll(ide)(633) with total loss of bean leaf photoactivity.
- Taxon
- Phaseolus vulgarisPhaseolus vulgarise0
- Treatment
- HCN and HN(3)e1
- Outcome
- photoactivitye1
- Direction
- total losse1
- Qualifier
- irreversible conversion of protochlorophyll(ide)(650) to protochlorophyll(ide)(633)e1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“dark-grown bean (Phaseolus vulgaris L. var. Red Kidney) seedlings”
e1“Compounds such as HCN and HN(3) cause an irreversible conversion of protochlorophyll(ide)(650) to protochlorophyll(ide)(633) with total loss of photoactivity”
Claim · model-written summary
Beta-mercaptoethanol and cysteine cause a slow, irreversible transformation of the photoactive pigment to the photoinactive form in bean leaves.
- Taxon
- Phaseolus vulgarisPhaseolus vulgarise0
- Treatment
- beta-mercaptoethanol and cysteinee1
- Outcome
- photoactive pigmente1
- Direction
- transformatione1
- Qualifier
- slow, irreversiblee1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“dark-grown bean (Phaseolus vulgaris L. var. Red Kidney) seedlings”
e1“Sulfhydryl agents, such as beta-mercaptoethanol and cysteine, cause a slow, irreversible transformation of the photoactive pigment to the photoinactive form and inhibit the ability of the leaves to synthesize chlorophyll under continuous illumination”
Claim · model-written summary
Beta-mercaptoethanol and cysteine inhibit the ability of bean leaves to synthesize chlorophyll under continuous illumination.
- Taxon
- Phaseolus vulgarisPhaseolus vulgarise0
- Treatment
- beta-mercaptoethanol and cysteinee1
- Outcome
- ability of the leaves to synthesize chlorophyll under continuous illuminatione1
- Direction
- inhibite1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“dark-grown bean (Phaseolus vulgaris L. var. Red Kidney) seedlings”
e1“Sulfhydryl agents, such as beta-mercaptoethanol and cysteine, cause a slow, irreversible transformation of the photoactive pigment to the photoinactive form and inhibit the ability of the leaves to synthesize chlorophyll under continuous illumination”
Claim · model-written summary
H2S may alter the interaction between the hydrogen source on the holochrome protein and the chromophore by reducing a protein disulfide bond.
- Taxon
- Phaseolus vulgarisPhaseolus vulgarise0
- Outcome
- interaction between the source of hydrogens on the protein moiety of the holochrome and the chromophoree1
- Qualifier
- reducing a disulfide bond in the proteine1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“dark-grown bean (Phaseolus vulgaris L. var. Red Kidney) seedlings”
e1“The results obtained suggest that H(2)S may alter the interaction between the source of hydrogens on the protein moiety of the holochrome and the chromophore in vivo by reducing a disulfide bond in the protein, thereby causing a reversible conformational change in the complex”
The same questions in other papers
hydrogen sulfide · nutrient: content · Phaseolus vulgaris (common bean)Positive and negative results
1 in the opposite direction
- positive
cysteine · physiology: pigments · Phaseolus vulgaris (common bean)Results agree
2 papers in the same direction as this paper
- negative
- 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.