Chloroplast evolution from photobacteria to endosymbiotic organelles of eukaryotes

1989 ◽  
Vol 19 (3-5) ◽  
pp. 427-428
Author(s):  
I. N. Stadnichuk
Keyword(s):  
Chloroplast Evolution

scholarly journals Chloroplast genomes in Populus (Salicaceae): comparisons from an intensively sampled genus reveal dynamic patterns of evolution

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiawei Zhou ◽  
Shuo Zhang ◽  
Jie Wang ◽  
Hongmei Shen ◽  
Bin Ai ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Population Level ◽  
Gene Content ◽  
Sequencing Data ◽  
Cellular Functions ◽  
Chloroplast Evolution ◽  
Chloroplast Genomes ◽  
Genome Features ◽  
Genome Annotations ◽  
Genome Analyses

AbstractThe chloroplast is one of two organelles containing a separate genome that codes for essential and distinct cellular functions such as photosynthesis. Given the importance of chloroplasts in plant metabolism, the genomic architecture and gene content have been strongly conserved through long periods of time and as such are useful molecular tools for evolutionary inferences. At present, complete chloroplast genomes from over 4000 species have been deposited into publicly accessible databases. Despite the large number of complete chloroplast genomes, comprehensive analyses regarding genome architecture and gene content have not been conducted for many lineages with complete species sampling. In this study, we employed the genus Populus to assess how more comprehensively sampled chloroplast genome analyses can be used in understanding chloroplast evolution in a broadly studied lineage of angiosperms. We conducted comparative analyses across Populus in order to elucidate variation in key genome features such as genome size, gene number, gene content, repeat type and number, SSR (Simple Sequence Repeat) abundance, and boundary positioning between the four main units of the genome. We found that some genome annotations were variable across the genus owing in part from errors in assembly or data checking and from this provided corrected annotations. We also employed complete chloroplast genomes for phylogenetic analyses including the dating of divergence times throughout the genus. Lastly, we utilized re-sequencing data to describe the variations of pan-chloroplast genomes at the population level for P. euphratica. The analyses used in this paper provide a blueprint for the types of analyses that can be conducted with publicly available chloroplast genomes as well as methods for building upon existing datasets to improve evolutionary inference.

Probabilistic Analysis Indicates Discordant Gene Trees in Chloroplast Evolution

2003 ◽  
Vol 56 (3) ◽  
pp. 330-340 ◽  
Author(s):  
Claus Vogl ◽  
Jonathan Badger ◽  
Paul Kearney ◽  
Ming Li ◽  
Michael Clegg ◽  
...  
Keyword(s):  
Probabilistic Analysis ◽  
Gene Trees ◽  
Chloroplast Evolution

Letters to the Editor: Pros and Cons of Chloroplast Evolution

Taxon ◽  
1975 ◽  
Vol 24 (2/3) ◽  
pp. 397
Author(s):  
Robert Edward Lee ◽  
F. J. R. Taylor
Keyword(s):  
Letters To The Editor ◽  
Chloroplast Evolution ◽  
Pros And Cons

scholarly journals CHLOROPLAST EVOLUTION

1981 ◽  
Vol 87 (2) ◽  
pp. 233-247 ◽  
Author(s):  
JEAN M. WHATLEY ◽  
F. R. WHATLEY
Keyword(s):  
Chloroplast Evolution

scholarly journals Outer membrane-deprived cyanobacteria liberate periplasmic and thylakoid luminal components that support the growth of heterotrophs

2020 ◽  
Author(s):  
Seiji Kojima ◽  
Yasuaki Okumura
Keyword(s):  
Host Cell ◽  
Outer Membrane ◽  
Cell Function ◽  
Heterotrophic Bacteria ◽  
Photosynthetic Electron Transport ◽  
Physical Interaction ◽  
Free Living ◽  
Chloroplast Evolution ◽  
Photosynthetic Products ◽  
Host Metabolism

ABSTRACTChloroplasts originate from endosymbiosis of a cyanobacterium within a heterotrophic host cell. Establishing endosymbiosis requires the translocation across its envelope of photosynthetic products generated inside the once free-living cyanobacterium to be exploited by host metabolism. However, the nature of this translocation event is unknown. We previously found that most cyanobacterial outer membrane components were eliminated during the primitive stage of chloroplast evolution, suggesting the importance of evolutionary changes of the outer membrane. Here, we removed the outer membrane from Synechocystis sp. PCC 6803 by disrupting the physical interaction with peptidoglycan, and characterized the effects on cell function. Outer membrane-deprived cells liberated diverse substances into the environment without significantly compromising photoautotrophic growth. The amount of liberated proteins increased to ~0.35 g/L within five days of culture. Proteomic analysis showed that most liberated proteins were periplasmic and thylakoid luminal components. Connectivity between the thylakoid lumen-extracellular space was confirmed by findings that an exogenous hydrophilic oxidant was reduced by photosynthetic electron transport chain on the thylakoid membrane. Metabolomic analysis detected the release of nucleotide-related metabolites at concentrations around 1 μM. The liberated materials supported the proliferation of heterotrophic bacteria. These findings show that breaching the outer membrane, without any manipulations to the cytoplasmic membrane, converts a cyanobacterium to a chloroplast-like organism that conducts photosynthesis and releases its biogenic materials. This conversion not only represents a potential explanation why the outer membrane markedly changed during the earliest stage of chloroplast evolution, but also provides the opportunity to harness cyanobacterial photosynthesis for biomanufacturing processes.SIGNIFICANCE STATEMENTAlthough it is well accepted that chloroplasts stem from endosymbiosis of a cyanobacterium within a heterotrophic host cell, the issue of how photosynthetic products generated inside a formerly free-living cyanobacterium are translocated across its envelope and exploited by host metabolism has been little addressed. Here we show that breaching the cyanobacterial outer membrane barrier converts a cyanobacterium to a chloroplast-like organism that conducts photosynthesis and releases its diverse biogenic materials into its external environment, which sustains the growth of heterotrophic organisms. This conversion represents a possible example of metabolic exploitation of cyanobacterial photosynthesis. Further, this “quasi-chloroplast” provides a potential opportunity for industrial application such as producing feedstock for biomanufacturing processes that harnesses heterotrophic bacteria.

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