Phylogenetic Origin of the Plastids

Valentin, Klaus; Cattolico, Rose Ann; Zetsche, Klaus

doi:10.1007/978-1-4615-2818-0_12

Cited by 21 publications

(17 citation statements)

References 102 publications

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“…As expected, the lowest similarities were observed to the L xtype (form II) RubisCO from R. sphaeroides and Rhodospirillum rubrum. The data support the hypothesis that the RubisCO genes of A. eutrophus, R. sphaeroides (form I), X. flavus, and strain S185-9A1 as well as those of members of the Chromophyta and Rhodophyta might have evolved from a common ancestor (49).…”

Section: Discussionsupporting

confidence: 82%

Characterization of the duplicate ribulose-1,5-bisphosphate carboxylase genes and cbb promoters of Alcaligenes eutrophus

et al. 1995

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Autotrophic CO 2 fixation via the Calvin carbon reduction cycle in Alcaligenes eutrophus H16 is genetically determined by two highly homologous cbb operons, one of which is located on the chromosome and the other on megaplasmid pHG1 of the organism. An activator gene, cbbR, lies in divergent orientation only 167 bp upstream of the chromosomal operon and controls the expression of both cbb operons. The two 5 -terminal genes of the operons, cbbLS, coding for ribulose-1,5-bisphosphate carboxylase/oxygenase, were sequenced. Mapping of the 5 termini of the 2.1-kb cbbLS transcripts by primer extension and by nuclease S1 treatment revealed a single transcriptional start point at the same relative position for the chromosomal and plasmidborne cbb operons. The derived cbb operon promoter showed similarity to 70 -dependent promoters of Escherichia coli. For the 1.4-kb transcripts of cbbR, the transcriptional start points were different in autotrophic and heterotrophic cells. The two corresponding cbbR promoters overlapped the cbb operon promoter and also displayed similarities to 70 -dependent promoters. The deficient cbbR gene located on pHG1 was transcribed as well. A newly constructed double operon fusion vector was used to determine the activities of the cbb promoters. Fusions with fragments carrying the cbb intergenic control regions demonstrated that the cbb operon promoters were strongly regulated in response to autotrophic versus heterotrophic growth conditions. In contrast, the cbbR promoters displayed low constitutive activities. The data suggest that the chromosomal and plasmid-borne cbb promoters of A. eutrophus H16 are functionally equivalent despite minor structural differences.The assimilation of CO 2 in the aerobic, facultatively autotrophic bacterium Alcaligenes eutrophus involves the operation of the Calvin carbon reduction cycle during either lithotrophic growth with hydrogen or organotrophic growth with formate as the sole energy source (11). With the exceptions of the triose-3-phosphate isomerase (EC 5.3.1.1) and pentose-5-phosphate isomerase (EC 5.3.1.6), all enzymes of the cycle, including the CO 2 -fixing ribulose-1,5-bisphosphate carboxylase/oxygenase (EC 4.1.1.39; RubisCO), are encoded within a large cbb operon (cbbLSXYEFPTZGKA) encompassing about 12.5 kilobase pairs (kb) (7,41,42). The RubisCO genes cbbLS form the 5Ј-terminal end of the operon. It is of physiological interest that the 2-phosphoglycolate phosphatase (EC 3.1.3.18) gene cbbZ is also part of the operon. The enzyme initiates the conversion of 2-phosphoglycolate, which is produced by the oxygenase activity of RubisCO, to 3-phosphoglycerate via the glycolate pathway (42). The functions of cbbX and cbbY are still unknown. A. eutrophus H16 possesses two copies of the cbb operon, one located on the chromosome and the other on megaplasmid pHG1. Both the chromosomal and the plasmidborne operon were shown to be functional by phenotypic complementation of pHG1-cured mutants deficient in CO 2 assimilation, carrying insertions of transposon Tn5...

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Section: Discussionsupporting

confidence: 82%

Characterization of the duplicate ribulose-1,5-bisphosphate carboxylase genes and cbb promoters of Alcaligenes eutrophus

et al. 1995

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“…Although most molecular studies of plastid genes indicate a common ancestor for all plastids, a polyphyletic origin of rhodoplasts and chloroplasts has been argued based primarily on differences in gene content (56) and sequence analysis of the large subunit of ribulose-1,5-bisphospate carboxylase (rbcL) (57). It is possible to reconcile these incongruities if widely divergent host taxa independently engulfed different, but genetically related, Cyanobacteria leading to the appearance of monophyletic plastids (2).…”

Section: Discussionmentioning

confidence: 99%

The origin of red algae: Implications for plastid evolution

Stiller

Hall

1997

Proc. Natl. Acad. Sci. U.S.A.

337

157

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The origin of the red algae has remained an enigma. Historically the Rhodophyta were classified first as plants and later as the most ancient eukaryotic organisms. Recent molecular studies have indicated similarities between red and green plastids, which suggest that there was a single endosymbiotic origin for these organelles in a common ancestor of the rhodophytes and green plants. Previous efforts to confirm or reject this effort by analyses of nuclear DNA have been inconclusive; thus, additional molecular markers are needed to establish the relationship between the host cell lineages, independent of the evolutionary history of their plastids. To furnish such a data set we have sequenced the largest subunit of RNA polymerase II from two red algae, a green alga and a relatively derived amoeboid protist. Phylogenetic analyses provide strong statistical support for an early evolutionary emergence of the Rhodophyta that preceded the origin of the line that led to plants, animals, and fungi. These data, which are congruent with results from extensive analyses of nuclear rDNA, argue for a reexamination of current models of plastid evolution.

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“…Chlorophytic and chromophytic photoautotrophs experienced an early evolutionary divergence (Douglas and Turner, 1991), and as a result, the structure of chromophytic alga1 genomes differ significantly from those of terrestrial plants and green algae (Valentin et al, 1992). Recently published phylogenetic analyses have demonstrated that chromophytic chloroplast genomes have unique combinations of the number, identity, and organization of their plastid-encoded genes (Kowallik et al, 1995;Reith and Munholland, 1995;Stirwalt et al, 1995).…”

mentioning

confidence: 99%

“…Vol. 11 5, 1997 (Hardison et al, 1992;Valentin et al, 1992;Kowallik et al, 1995). Although the structure of chromophytic genomes has begun to be analyzed, the mechanisms that govern the response of these unique genomes to light cues have not been well studied.…”

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confidence: 99%

Photoregulation of Chloroplast Gene Transcription in the Chromophytic Alga Heterosigma carterae

Doran

Cattolico

1997

Plant Physiology

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Light acts as a complex regulator of cellular development and gene expression in photoautotrophs. Although light signals are highly effective in controlling cellular division and chloroplast biogenesis in the toxic marine alga Heterosigma carterae, their influence on gene expression has not been well characterized. To address this need cultures of H. carterae synchronized by an alternating light-dark regime were sampled through 12 h of light and 12 h of dark to characterize cell division, chloroplast complement, and chloroplast RNA abundance. These studies have identified a unimodal pattern of chloroplast transcriptional activity for a suite of cellular and photosynthetic genes. To determine the alga's response to a change in photoperiod, 12-h light/12-h dark-synchronized cultures were transferred to constant light and then periodically sampled. Although cellular and chloroplast division cycles remained synchronized in constant conditions for 24 h, the transcriptional apparatus responded by increasing ctRNA abundance within 45 min of the change in photoperiod. However, the ability of the alga to mount this rapid transcriptional response was limited to the first 2 h of the putative dark period. Thus, the chloroplast transcriptional apparatus of H. carterae may initiate a rapid, temporally gated response to a change in photoperiod that is independent of ongoing light-entrained cellular and chloroplast division cycles.

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Phylogenetic Origin of the Plastids

Cited by 21 publications

References 102 publications

Characterization of the duplicate ribulose-1,5-bisphosphate carboxylase genes and cbb promoters of Alcaligenes eutrophus

Characterization of the duplicate ribulose-1,5-bisphosphate carboxylase genes and cbb promoters of Alcaligenes eutrophus

The origin of red algae: Implications for plastid evolution

Photoregulation of Chloroplast Gene Transcription in the Chromophytic Alga Heterosigma carterae

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