Abstract
1. Chlorophyll (ide) formation from protochlorophyll (ide) that is normally inactive was demonstrated in etioplast membranes isolated from maize and barlley plants, the process being dependent on intermittent illumination and the addition of NADPH. 2. The addition of NADPH to the membranes was shown to result in the conversion of inactive protochlorophyll (ide) absorbing at about 630 nm into a form(s) with light-absorption maxima at about 640 and 652 nm, both of which disappear when chlorophyll (ide) is formed on illumination. 3. The temperature-dependence of the activation process and its response to a variety of reagents were examined. From these, the conclusion is drawn that -SH groups are involved in the activation but in the active complex these are unavailable for reaction with -SH reagents. 4. Evidence is presented for the occurrence of glucose 6-phosphate dehydrogenase activity within etioplasts and the suggestion is made that the oxidative pentose phosphate pathway can provide the NADPH required for chlorophyll biosynthesis during the early stages of greening.
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Claims 7
Claim · model-written summary
Chlorophyllide formation from inactive protochlorophyllide occurred in maize membranes with intermittent illumination and NADPH.
- Organ / stage
- etioplast membranese0
- Treatment
- intermittent illumination and the addition of NADPHe0
- Outcome
- Chlorophyll (ide) formatione0
Zea maysNot reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Chlorophyll (ide) formation from protochlorophyll (ide) that is normally inactive was demonstrated in etioplast membranes isolated from maize and barlley plants, the process being dependent on intermittent illumination and the addition of NADPH”
Claim · model-written summary
Chlorophyllide formation from inactive protochlorophyllide occurred in barley membranes with intermittent illumination and NADPH.
- Taxon
- barlleye0
- Organ / stage
- etioplast membranese0
- Treatment
- intermittent illumination and the addition of NADPHe0
- Outcome
- Chlorophyll (ide) formatione0
Not reportedComparatorDirection
Verbatim
e0“Chlorophyll (ide) formation from protochlorophyll (ide) that is normally inactive was demonstrated in etioplast membranes isolated from maize and barlley plants, the process being dependent on intermittent illumination and the addition of NADPH”
Claim · model-written summary
NADPH converted inactive protochlorophyllide into forms absorbing near 640 and 652 nm.
- Treatment
- addition of NADPHe0
- Outcome
- conversion of inactive protochlorophyll (ide)e0
- Value
- about 640 and 652 nme0
Not reportedTaxonComparatorDirection
Verbatim
e0“The addition of NADPH to the membranes was shown to result in the conversion of inactive protochlorophyll (ide) absorbing at about 630 nm into a form(s) with light-absorption maxima at about 640 and 652 nm”
Claim · model-written summary
The 640 and 652 nm forms disappeared after illumination formed chlorophyllide.
Not reportedTaxonDirection
Verbatim
e0“both of which disappear when chlorophyll (ide) is formed on illumination”
Claim · model-written summary
Thiol groups were inferred to participate in activation but to be inaccessible in the active complex.
Not reportedTaxon
Verbatim
e0“the conclusion is drawn that -SH groups are involved in the activation but in the active complex these are unavailable for reaction with -SH reagents”
Claim · model-written summary
Glucose 6-phosphate dehydrogenase activity was found in etioplasts.
- Organ / stage
- etioplastse0
- Gene
- glucose 6-phosphate dehydrogenasee0
- Outcome
- glucose 6-phosphate dehydrogenase activitye0
Not reportedTaxon
Verbatim
e0“Evidence is presented for the occurrence of glucose 6-phosphate dehydrogenase activity within etioplasts”
Claim · model-written summary
The oxidative pentose phosphate pathway was suggested as a source of NADPH for early greening.
Not reportedTaxon
Verbatim
e0“the suggestion is made that the oxidative pentose phosphate pathway can provide the NADPH required for chlorophyll biosynthesis during the early stages of greening”
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See all 21 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.