Abstract
Using incorporation of exogenous substrates in chlorophyll biosynthesis chain it was found that in etiolated leaves there is a machinery capable of chlorophyllide a to chlorophyll a and chlorophyllide b to chlorophyll b transformations as well as inverse transformation of chlorophyll b into chlorophyll a. Immunochemical methods were employed to reveal protein precursors of pigment-protein complex I, pigment-protein complex II and light-harvesting complex in etioplasts. The investigation of the fluorescence excitation spectra has shown that just after illumination of etiolated leaves Photosystem I appears as a system of respective chlorophyll forms with an efficient energy sink to the longwave minor form emitting at 720 nm. The study of delayed luminescence indicates that Photosystem II arises as early as during the Shibata shift. While being incorporated into Photosystems, chlorophyll molecules undergo at least two translocations from the sites of their synthesis. Chlorophyll 672 is likely to be a special pigment pool utilized for the construction of the photosynthetic apparatus. In the course of the Shibata shift, the translocation rate of chlorophyll molecules to the new surrounding varies within ontogenesis of seedlings and also under the influence of chloramphenicol and cycloheximide. Meanwhile, there is no rapid photoinduced synthesis of new proteins in plastids. Photoinduced increase of the chlorophyll synthesis rate in greening leaves is accompanied by accumulation of magnesium protoporphyrin IX monomethyl ester, and the constant rate of greening coincides with a decrease of the intermediate content. The analysis of the pigment synthesis rates under continuous and intermittent illumination suggests existence of two types of the centers of chlorophyll biosynthesis which differ in the light regulation of 6-aminolevulinic acid synthesis and, probably, in their abilities to produce chlorophylls a and b.
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Claims 12
Claim · model-written summary
Etiolated leaves can convert chlorophyllide a to chlorophyll a, chlorophyllide b to chlorophyll b, and chlorophyll b back to chlorophyll a.
- Outcome
- chlorophyllide a to chlorophyll a and chlorophyllide b to chlorophyll b transformations as well as inverse transformation of chlorophyll b into chlorophyll ae0
Not reportedTaxonDirection
Verbatim
e0“in etiolated leaves there is a machinery capable of chlorophyllide a to chlorophyll a and chlorophyllide b to chlorophyll b transformations as well as inverse transformation of chlorophyll b into chlorophyll a”
Claim · model-written summary
Etioplasts contain protein precursors of three pigment protein complexes.
- Organ / stage
- etioplastse0
- Outcome
- protein precursors of pigment-protein complex I, pigment-protein complex II and light-harvesting complexe0
Not reportedTaxonDirection
Verbatim
e0“protein precursors of pigment-protein complex I, pigment-protein complex II and light-harvesting complex in etioplasts”
Claim · model-written summary
Photosystem I appears immediately after illumination, with an energy sink at the longwave form emitting at 720 nm.
Not reportedTaxonDirection
Verbatim
e0“just after illumination of etiolated leaves Photosystem I appears as a system of respective chlorophyll forms with an efficient energy sink to the longwave minor form emitting at 720 nm”
Claim · model-written summary
Photosystem II arises during the Shibata shift.
Not reportedTaxonDirection
Verbatim
e0“Photosystem II arises as early as during the Shibata shift”
Claim · model-written summary
Chlorophyll molecules undergo at least two translocations during incorporation into photosystems.
- Outcome
- chlorophyll molecules undergo at least two translocationse0
- Value
- at least two translocationse0
Not reportedTaxonDirection
Verbatim
e0“While being incorporated into Photosystems, chlorophyll molecules undergo at least two translocations from the sites of their synthesis”
Claim · model-written summary
Chlorophyll 672 is proposed as a pigment pool used to build the photosynthetic apparatus.
Not reportedTaxonDirection
Verbatim
e0“Chlorophyll 672 is likely to be a special pigment pool utilized for the construction of the photosynthetic apparatus”
Claim · model-written summary
Chlorophyll translocation rate varies with seedling ontogenesis during the Shibata shift.
Not reportedTaxonDirection
Verbatim
e0“the translocation rate of chlorophyll molecules to the new surrounding varies within ontogenesis of seedlings”
Claim · model-written summary
Chloramphenicol and cycloheximide influence chlorophyll translocation rate during the Shibata shift.
Not reportedTaxonComparatorDirection
Verbatim
e0“the translocation rate of chlorophyll molecules to the new surrounding varies within ontogenesis of seedlings and also under the influence of chloramphenicol and cycloheximide”
Claim · model-written summary
Rapid light induced synthesis of new plastid proteins was absent.
- Outcome
- no rapid photoinduced synthesis of new proteins in plastidse0
Not reportedTaxonDirection
Verbatim
e0“there is no rapid photoinduced synthesis of new proteins in plastids”
Claim · model-written summary
An increase in chlorophyll synthesis rate accompanies accumulation of magnesium protoporphyrin IX monomethyl ester.
- Compound
- magnesium protoporphyrin IX monomethyl estere0
- Outcome
- chlorophyll synthesis ratee0
- Direction
- increasee0
Not reportedTaxon
Verbatim
e0“Photoinduced increase of the chlorophyll synthesis rate in greening leaves is accompanied by accumulation of magnesium protoporphyrin IX monomethyl ester”
Claim · model-written summary
A constant greening rate coincides with a decrease in intermediate content.
Not reportedTaxonOrgan / stage
Verbatim
e0“the constant rate of greening coincides with a decrease of the intermediate content”
Claim · model-written summary
Pigment synthesis rates suggest two chlorophyll biosynthesis center types with different light regulation of 6-aminolevulinic acid synthesis and possibly different chlorophyll a and b production.
- Outcome
- two types of the centers of chlorophyll biosynthesise0
- Qualifier
- light regulation of 6-aminolevulinic acid synthesise0
Not reportedTaxonDirection
Verbatim
e0“suggests existence of two types of the centers of chlorophyll biosynthesis which differ in the light regulation of 6-aminolevulinic acid synthesis and, probably, in their abilities to produce chlorophylls a and b”