Characterization of prolamellar bodies and prothylakoids fractionated from wheat etioplasts

Ryberg, Margareta; Sundqvist, Christer

doi:10.1111/j.1399-3054.1982.tb00313.x

Cited by 145 publications

(117 citation statements)

References 29 publications

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“…Previous studies on the effects of FR irradiation on plastid structure have revealed that this treatment leads to a deficiency in the ordered membrane system of the prolamellar body (Oelmü ller et al, 1986;Barnes et al, 1996;Sperling et al, 1997). This can be largely attributed to the dramatic decline in PORA (Runge et al, 1996), which is the major protein component of the prolamellar body (Ryberg and Sundqvist, 1982;Ikeuchi and Murakami, 1983). In addition, the development of vesicles, which may be related to degradation of plastid components, has also been observed (Barnes et al, 1996).…”

Section: The Transcriptionally Coupled Response Results In the Loss Omentioning

confidence: 95%

Loss of Nuclear Gene Expression during the Phytochrome A-Mediated Far-Red Block of Greening Response

McCormac

Terry

2002

Plant Physiology

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We have examined the expression of the HEMA1 gene, which encodes the key chlorophyll synthesis enzyme glutamyl-tRNA reductase, during the phytochrome A-mediated far-red light (FR) block of greening response in Arabidopsis. Our results demonstrate that the FR block of greening comprises two separate responses: a white light (WL) intensity-independent response that requires 3 d of FR and is associated with a loss of expression of the nuclear genes HEMA1 and Lhcb following the transfer to WL (transcriptionally coupled response) and a WL intensity-dependent response that is induced by 1 d of FR and is transcriptionally uncoupled. Both responses required phytochrome A. The transcriptionally uncoupled response correlated with a deregulation of tetrapyrrole synthesis and potential photooxidative damage and was inhibited by cytokinin. The transcriptionally coupled FR response was additive with the loss of expression following Norflurazoninduced photobleaching and was absent in the presence of sucrose or after lower fluence rate (1 mol m Ϫ2 s Ϫ1 ) FR treatments. Both pathways leading to the loss of nuclear gene expression were inhibited by overexpression of NADPH: protochlorophyllide oxidoreductase, indicating a role for plastid signaling in the FR-mediated pathway. The significance of identifying a distinct phytochrome A-mediated plastid signaling pathway is discussed.The coordinated synthesis of chlorophylls and chlorophyll-binding proteins is critically important during emergence of the etiolated seedling into light, and is essential for the normal development of functional chloroplasts. The key regulatory step in chlorophyll synthesis is the formation of 5-aminolevulinic acid (ALA), which is rate limiting for the tetrapyrrole pathway (Beale and Castelfranco, 1974). As a consequence, inhibition of ALA synthesis through inhibitors or anti-sense approaches (Hö fgen et al., 1994;Kumar and Sö ll, 2000) has a dramatic effect on chloroplast development, resulting in plants that are highly susceptible to photobleaching. In a converse manner, excess ALA also affects chloroplast development (Kittsteiner et al., 1991) and leads to an overaccumulation of porphyrins, which can lead to severe photooxidative damage (Reinbothe et al., 1996).Uncoupling tetrapyrrole synthesis from chloroplast development may also be achieved by irradiating etiolated seedlings with far-red (FR) light (Barnes et al., 1996;Runge et al., 1996). Growth of Arabidopsis seedlings under continuous FR (FRc) can induce partial photomorphogenesis with reduced hypocotyl elongation growth and cotyledon expansion. These responses are characteristic of the FR-high-irradiance response (FR-HIR;Mancinelli, 1994), which is a specific function of phytochrome A (Smith, 1995). FRc irradiation can also activate many of the processes required for chloroplast development. These include the induction of nuclear genes encoding chlorophyll a/b-binding proteins and other photosynthetic proteins (Kuno et al., 2000;Tepperman et al., 2001) and the transcription of chloroplast genes ...

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Section: The Transcriptionally Coupled Response Results In the Loss Omentioning

confidence: 95%

Loss of Nuclear Gene Expression during the Phytochrome A-Mediated Far-Red Block of Greening Response

McCormac

Terry

2002

Plant Physiology

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“…Protein Analyses-Three different methods were employed to prepare and analyze POR-pigment complexes, that of Ryberg and Sundqvist (26), that of Klement et al (27), and a modified version of that of Gerhardt and Heldt (28).…”

Section: Methodsmentioning

confidence: 99%

In Vitro Reconstitution of Light-harvesting POR-Protochlorophyllide Complex with Protochlorophyllides a and b

Reinbothe¹,

Buhr²,

Pollmann³

et al. 2003

Journal of Biological Chemistry

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“…We previously showed that glycolipid composition of PLB and PT fractions was qualitatively similar (22). Ryberg and Sundqvist (21) and Ikeuchi and Murakami (10) showed that PT fractions contained several polypeptides while the PLB fraction was dominated by one polypeptide. The methods used in these studies (10,21,22) for separating PLBs and PTs resulted in pure PLB fractions whereas the PT fractions probably contained PLB fragments and/or envelope membranes.…”

mentioning

confidence: 99%

A Comparison between Prolamellar Bodies and Prothylakoid Membranes of Etioplasts of Dark-Grown Wheat Concerning Lipid and Polypeptide Composition

Selstam¹,

Sandelius²

1984

Plant Physiol.

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The aim of the present investigation was to find factors critical for the co-existence of prolamellar bodies and prothylakoids in etioplasts of wheat (Triticum aestivum L. cv Starke II). The lipid composition of the prolamellar body and prothylakoid fractions was qualitatively similar. However, the molar ratio of m ogalactosyl diacy4gycerol to digaactosyl diacylglycerol was higher in the prolamellar body fraction (1.6 ± 0.1), as was the lipid content on a protein basis. Protochlorophyllide was present in both fractions. The system with the planar bilayer membranes of PT (13,20). It is therefore reasonable to assume that several membrane components are common between PLBs and PTs. We previously showed that glycolipid composition of PLB and PT fractions was qualitatively similar (22). Ryberg and Sundqvist (21) and Ikeuchi and Murakami (10) showed that PT fractions contained several polypeptides while the PLB fraction was dominated by one polypeptide. The methods used in these studies (10, 21, 22) for separating PLBs and PTs resulted in pure PLB fractions whereas the PT fractions probably contained PLB fragments and/or envelope membranes.To study which factors could be important for the existence of the continuous system of prothylakoid membranes and branched prolamellar body membranes, a PT fraction representing prothylakoids that in situ had been connected with PLBs was needed. A method for isolating such a PT fraction, as well as a PLB fraction, has been previously described (23). In the present investigation, this method was used for isolating a PLB and a PT fraction. These fractions were compared with respect to lipid, pigment, and polypeptide composition with the aim of finding which compositional differences could explain the structural differences in membrane organization between PLBs and PTs. The generally accepted model for the organization of lipids and proteins in a membrane is the fluid mosaic membrane model, proposed by Singer and Nicolson (26). According to this model, the lipids form a planar bilayer in which the proteins are more or less embedded. Membrane lipids and proteins can also form branched bilayer structures in the cells. In plants, the most conspicuous ones are the crystalline PLBs2, found in plastids. Based on ultrastructural studies, the structure of the PLB is considered to be a branched lattice constructed of four-or sixarmed units (5,8,30). The PLBs are found in developing plastids (33), in etioplasts (32), and in nonirradiated chloroplasts (9, 12). It has been proposed that the PLBs store material to be utilized in the assembly of membranes at later stages of plastid development (20,34 MATERIAIS AND METHODSIsolation of Membrane Fractions. Etioplasts were isolated from dark-grown wheat (Triticum aestivum L. cv Starke II Weibull, Sweden) and purified on a Percoll gradient. After osmotical and mechanical rupture of the plastids, a fraction rich in envelope membranes ('env'), a PLB fraction, and a PT fraction were isolated according to Figure 1. After centrifugation of the ru...

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Characterization of prolamellar bodies and prothylakoids fractionated from wheat etioplasts

Cited by 145 publications

References 29 publications

Loss of Nuclear Gene Expression during the Phytochrome A-Mediated Far-Red Block of Greening Response

Loss of Nuclear Gene Expression during the Phytochrome A-Mediated Far-Red Block of Greening Response

In Vitro Reconstitution of Light-harvesting POR-Protochlorophyllide Complex with Protochlorophyllides a and b

A Comparison between Prolamellar Bodies and Prothylakoid Membranes of Etioplasts of Dark-Grown Wheat Concerning Lipid and Polypeptide Composition

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