Chloroplast biogenesis

Mattheis, James R.; Rebeiz, Constantin A.

doi:10.1016/0003-9861(77)90341-1

Cited by 17 publications

(6 citation statements)

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“…well-established cell-free systems have been successfully used in demonstrating the conversion of various tetrapyrroles into Pchlide a and Chi a (Mattheis & Rebeiz, 1977b-d). Since it was not possible to demonstrate with these same cell-free systems a precursor-product relationship between Pchlide and Pchlide ester (Mattheis & Rebeiz, 1977a), this was taken as further proof for the operation of a two-branched Pchl(ide) biosynthetic pathway in plants (Rebeiz et al, 1978). It was therefore conjectured that a detailed cell-free study of the precursor-product relationships among various intermediates of the Pchl(ide) pathway might help to determine the precise location of the branching point in the proposed two-branched pathway.…”

Section: Resultsmentioning

confidence: 99%

“…of [14C] ALA in a total volume of 5.5 mL (Mattheis & Rebeiz, 1977a). In preparing [14C]MPE, the incubation also included 20 µ of , ,'-dipyridyl dissolved in 0.03 mL of methanol (Mattheis & Rebeiz, 1977b).…”

Section: Methodsmentioning

confidence: 99%

“…The proposal of the above pathway was based on the following observations, (a) Kinetic analysis of [14C]ALA incorporation into the Pchlide and the Pchlide ester pools2 ***&in vivo was only compatible with biosynthetic models that involved the formation of Pchlide and Pchlide ester in parallel from a common precursor (Rebeiz et al, 1970). (b) Investigations of a possible precursor-product relationship between [14C]Pchlide and [14C]Pchlide ester in crude homogenates (Ellsworth & Nowak, 1973) and in isolated etiochloroplasts (Mattheis & Rebeiz, 1977a) failed to demonstrate the conversion of [14C]Pchlide into [14C]Pchlide ester and vice versa.…”

mentioning

confidence: 97%

“…These results led in turn to the conclusion that the Pchlide and Pchlide ester pools were not metabolically interconnected in greening tissues (Mattheis & Rebeiz, 1977a). (c) The very recent discovery of a fully esterified MPE-7 ester pool in plant tissues (Figure 1) suggested that the tetrapyrrole precursors of Pchlide ester may be fully esterified Mg-porphyrins (McCarthy et al, 1981).…”

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confidence: 99%

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Chloroplast biogenesis: biosynthesis of protochlorophyll(ide) via acidic and fully esterified biosynthetic branches in higher plants

McCarthy¹,

Mattheis²,

Rebeiz³

1982

Biochemistry

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The operation of two parallel biosynthetic pathways during the biosynthesis of the protochlorophyll(ide) pool of cucumber cotyledons was probed with the use of several [14C]tetrapyrroles in vitro. A comparison of the ratio (R) of delta-amino[14C]levulinic acid incorporation into protochlorophyllide/14C incorporation into protochlorophyllide ester with other incorporation ratios, RX, where X represents any of several [14C]tetrapyrrole substrates, allowed us to determine which exogenous 14C-labeled substrate was common precursor of protochlorophyllide and protochlorophyllide ester and which one was not. From such comparisons, a biosynthetic pathway of protochlorophyll(ide) biosynthesis is inferred. According to this pathway, protochlorophyllide is formed via an acidic (mono/dicarboxylic) biosynthetic branch, while protochlorophyllide ester is formed via a fully esterified (neutral) biosynthetic branch. The two biosynthetic branches are linked together by porphyrin ester synthetases at the level of protochlorophyllides and possibly at the level of the photoporphyrin IX and the magnesium protoporphyrin monoester pools.

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 97%

mentioning

confidence: 99%

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Chloroplast biogenesis: biosynthesis of protochlorophyll(ide) via acidic and fully esterified biosynthetic branches in higher plants

McCarthy¹,

Mattheis²,

Rebeiz³

1982

Biochemistry

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“…"C-labeled Pchlide was prepared as described previously (Mattheis and Rebeiz, 1977b). Briefly, etiolated cotyledons were harvested in the dark and illuminated with 3.2W/mf of cool white fluorescent light for 5 min to phototransform as much of the endogenous Pchlide as possible.…”

Section: Introductionmentioning

confidence: 99%

CHLOROPLAST BIOGENESIS. XXIII. THE CONVERSION OF EXOGENOUS PROTOCHLOROPHYLLIDE INTO PHOTOTRANSFORMABLE PROTOCHLOROPHYLLIDE *IN VITRO**

Mattheis

Rebeiz

1978

Photochem & Photobiology

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Abstract— An in vitro assay is described for the quantitative conversion of nonphototransformable protochlorophyllide into phototransformable protochlorophyllide. The assay involves: (a) the conversion of exogenous nonphototransformable protochlorophyllide into phototransformable protochlorophyllide in the dark, and (b) the quantitative monitoring of this conversion by the disappearance of the phototransformable protochlorophyllide as it is converted to chlorophyllide a by a single, 15 s illumination. This was achieved under conditions where no significant photodestruction of protochlorophyllide occurred. The formation of phototransformable protochlorophyllide from nonphototransformable protochlorophyllide in vitro was further demonstrated by the conversion of exogenous nonphototransformable [14C]protochlorophyllide into [14C]chlorophyll. This was achieved in three steps: (a) the conversion of nonphototransformable [14C]protochlorophyllide into phototransformable [14C]protochlorophyllide in the dark; (b) the conversion of phototransformable [14C]protochlorophyllide into [14C]chlorophyllide a by a single 15 s illumination; and (c) the esterification of the newly formed [14C]chlorophyllide a to yield [14C]chlorophyll. The extent of these reactions was monitored by the incorporation of the 14C‐label into chlorophyll. About 96% of the radioactivity in the [14C]chlorophyll fraction was found in [14C]chlorophyll a.

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Bioengineering of photosynthetic membranes. Requirement of magnesium for the conversion of chlorophyllide a to chlorophyll a during the greening of etiochloroplasts in vitro

Daniell

Rebeiz

1984

Biotech & Bioengineering

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The massive conversion of delta-aminolevulinic acid (ALA) to protochlorophyllide (Pchlide) and the massive conversion of chlorophyllide a (Chlide a) to chlorophyll a (Chl a) are two essential conditions for the ALA-dependent assembly of photosynthetic membranes in vitro. In this work, we describe the development of a cell-free system capable of the forementioned biosynthetic activities at rates higher than in vivo, for the first 2 h of dark-incubation. The cell-free system consisted of (1) etiochloroplasts prepared from kinetin and gibberellic-acid-pretreated cucumber cotyledons, and (2) cofactors and additives described elsewhere and which are needed for the massive conversion of ALA to Pchlide, (3) high concentrations of ATP, MgCl(2), and an isoprenol alcohol such as phytol, were required for the massive conversion of Chlide a to Chl a. An absolute and novel requirement of Mg(2+) for the conversion of Chlide a to Chl a was also demonstrated. In addition to the role of phytol as a substrate for the conversion of Chlide a to Chl a, the data suggested that this alcohol may also be involved in the regulation of the reactions between ALA and Pchlide. It is proposed that during greening, the conversion of Chlide a to Chl a may follow different biosynthetic rates, having different substrate and cofactor requirements, depending on the stage of plastid development.

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Chloroplast biogenesis

Cited by 17 publications

References 17 publications

Chloroplast biogenesis: biosynthesis of protochlorophyll(ide) via acidic and fully esterified biosynthetic branches in higher plants

Chloroplast biogenesis: biosynthesis of protochlorophyll(ide) via acidic and fully esterified biosynthetic branches in higher plants

CHLOROPLAST BIOGENESIS. XXIII. THE CONVERSION OF EXOGENOUS PROTOCHLOROPHYLLIDE INTO PHOTOTRANSFORMABLE PROTOCHLOROPHYLLIDE *IN VITRO**

Bioengineering of photosynthetic membranes. Requirement of magnesium for the conversion of chlorophyllide a to chlorophyll a during the greening of etiochloroplasts in vitro

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Chloroplast biogenesis

Cited by 17 publications

References 17 publications

Chloroplast biogenesis: biosynthesis of protochlorophyll(ide) via acidic and fully esterified biosynthetic branches in higher plants

Chloroplast biogenesis: biosynthesis of protochlorophyll(ide) via acidic and fully esterified biosynthetic branches in higher plants

CHLOROPLAST BIOGENESIS. XXIII. THE CONVERSION OF EXOGENOUS PROTOCHLOROPHYLLIDE INTO PHOTOTRANSFORMABLE PROTOCHLOROPHYLLIDE IN VITRO*

Bioengineering of photosynthetic membranes. Requirement of magnesium for the conversion of chlorophyllide a to chlorophyll a during the greening of etiochloroplasts in vitro

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CHLOROPLAST BIOGENESIS. XXIII. THE CONVERSION OF EXOGENOUS PROTOCHLOROPHYLLIDE INTO PHOTOTRANSFORMABLE PROTOCHLOROPHYLLIDE *IN VITRO**