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Current Biology : CB Apr 2018de Vries and Archibald introduce the topic of plastid genomes - prokaryotic genomes housed within eukaryotic algae and plants. (Review)
Review
de Vries and Archibald introduce the topic of plastid genomes - prokaryotic genomes housed within eukaryotic algae and plants.
Topics: Cyanobacteria; Evolution, Molecular; Genome, Plastid; Phylogeny; Plants; Plastids; Symbiosis
PubMed: 29689202
DOI: 10.1016/j.cub.2018.01.027 -
Current Opinion in Plant Biology Apr 2022The plastid (chloroplast) genome of seed plants represents an attractive target of metabolic pathway engineering by genetic transformation. Although the plastid genome... (Review)
Review
The plastid (chloroplast) genome of seed plants represents an attractive target of metabolic pathway engineering by genetic transformation. Although the plastid genome is relatively small, it can accommodate large amounts of foreign DNA that precisely integrates via homologous recombination, and is largely excluded from pollen transmission due to the maternal mode of plastid inheritance. Since the engineering of metabolic pathways often requires the expression of multiple transgenes, the possibility to conveniently stack transgenes in synthetic operons makes the transplastomic technology particularly appealing in the area of metabolic engineering. Absence of epigenetic gene silencing mechanisms from plastids and the possibility to achieve high transgene expression levels further add to the attractiveness of plastid genome transformation. This review focuses on engineering principles and available tools for the transplastomic expression of enzymes and pathways, and highlights selected recent applications in metabolic engineering.
Topics: Chloroplasts; Genetic Engineering; Metabolic Engineering; Plants, Genetically Modified; Plastids; Transgenes
PubMed: 35183927
DOI: 10.1016/j.pbi.2022.102185 -
Journal of Experimental Botany Nov 2022In plants, plastids are thought to interconvert to various forms that are specialized for photosynthesis, starch and oil storage, and diverse pigment accumulation.... (Review)
Review
In plants, plastids are thought to interconvert to various forms that are specialized for photosynthesis, starch and oil storage, and diverse pigment accumulation. Post-endosymbiotic evolution has led to adaptations and specializations within plastid populations that align organellar functions with different cellular properties in primary and secondary metabolism, plant growth, organ development, and environmental sensing. Here, we review the plastid biology literature in light of recent reports supporting a class of 'sensory plastids' that are specialized for stress sensing and signaling. Abundant literature indicates that epidermal and vascular parenchyma plastids display shared features of dynamic morphology, proteome composition, and plastid-nuclear interaction that facilitate environmental sensing and signaling. These findings have the potential to reshape our understanding of plastid functional diversification.
Topics: Plastids; Plant Development; Photosynthesis; Secondary Metabolism; Symbiosis
PubMed: 35994779
DOI: 10.1093/jxb/erac334 -
Trends in Plant Science Oct 2019Protein amino (N) termini are major determinants of protein stability in the cytosol of eukaryotes and prokaryotes, conceptualized in the N-end rule pathway, lately... (Review)
Review
Protein amino (N) termini are major determinants of protein stability in the cytosol of eukaryotes and prokaryotes, conceptualized in the N-end rule pathway, lately referred to as N-degron pathways. Here we argue for the existence of N-degron pathways in plastids of apicomplexa, algae, and plants. The prokaryotic N-degron pathway depends on a caseinolytic protease (CLP) S recognin (adaptor) for the recognition and delivery of N-degron-bearing substrates to CLP chaperone-protease systems. Diversified CLP systems are found in chloroplasts and nonphotosynthetic plastids, including CLPS homologs that specifically interact with a subset of N-terminal residues and stromal proteins. Chloroplast N-terminome data show enrichment of classic stabilizing residues [Ala (A), Ser (S), Val (V), Thr (T)] and avoidance of charged and large hydrophobic residues. We outline experimental test strategies for plastid N-degron pathways.
Topics: Chloroplasts; Endopeptidase Clp; Plastids
PubMed: 31300194
DOI: 10.1016/j.tplants.2019.06.013 -
Plant Cell Reports Jul 2019
Topics: Chloroplasts; Homeostasis; Organelle Biogenesis; Plants; Plastids; Protein Transport; Signal Transduction; Stress, Physiological
PubMed: 31165906
DOI: 10.1007/s00299-019-02437-7 -
Plant Cell Reports Jul 2019Plant cells are characterized by a unique group of interconvertible organelles called plastids, which are descended from prokaryotic endosymbionts. The most studied... (Review)
Review
Plant cells are characterized by a unique group of interconvertible organelles called plastids, which are descended from prokaryotic endosymbionts. The most studied plastid type is the chloroplast, which carries out the ancestral plastid function of photosynthesis. During the course of evolution, plastid activities were increasingly integrated with cellular metabolism and functions, and plant developmental processes, and this led to the creation of new types of non-photosynthetic plastids. These include the chromoplast, a carotenoid-rich organelle typically found in flowers and fruits. Here, we provide an introduction to non-photosynthetic plastids, and then review the structures and functions of chromoplasts in detail. The role of chromoplast differentiation in fruit ripening in particular is explored, and the factors that govern plastid development are examined, including hormonal regulation, gene expression, and plastid protein import. In the latter process, nucleus-encoded preproteins must pass through two successive protein translocons in the outer and inner envelope membranes of the plastid; these are known as TOC and TIC (translocon at the outer/inner chloroplast envelope), respectively. The discovery of SP1 (suppressor of ppi1 locus1), which encodes a RING-type ubiquitin E3 ligase localized in the plastid outer envelope membrane, revealed that plastid protein import is regulated through the selective targeting of TOC complexes for degradation by the ubiquitin-proteasome system. This suggests the possibility of engineering plastid protein import in novel crop improvement strategies.
Topics: Chloroplast Proteins; Chloroplasts; Organelles; Plant Proteins; Plasmids; Plastids; Protein Transport
PubMed: 31079194
DOI: 10.1007/s00299-019-02420-2 -
Trends in Cell Biology Jan 2016Chloroplasts depend on the nucleus for much of their proteome. Consequently, strong transcriptional coordination exists between the genomes, which is attuned to the...
Chloroplasts depend on the nucleus for much of their proteome. Consequently, strong transcriptional coordination exists between the genomes, which is attuned to the developmental and physiological needs of the organelle. Recent studies highlight that the post-translational modifier ubiquitin adds another layer to plastid homeostasis and even helps eliminate damaged chloroplasts.
Topics: Cell Nucleus; Chloroplasts; Humans; Plastids; Proteome; Ubiquitin
PubMed: 26706380
DOI: 10.1016/j.tcb.2015.12.001 -
Plant Cell Reports Jul 2023Novel episomal systems have the potential to accelerate plastid genetic engineering for application in plant synthetic biology. Plastids represent valuable subcellular... (Review)
Review
Novel episomal systems have the potential to accelerate plastid genetic engineering for application in plant synthetic biology. Plastids represent valuable subcellular compartments for genetic engineering of plants with intrinsic advantages to engineering the nucleus. The ability to perform site-specific transgene integration by homologous recombination (HR), coordination of transgene expression in operons, and high production of heterologous proteins, all make plastids an attractive target for synthetic biology. Typically, plastid engineering is performed by homologous recombination; however, episomal-replicating vectors have the potential to accelerate the design/build/test cycles for plastid engineering. By accelerating the timeline from design to validation, it will be possible to generate translational breakthroughs in fields ranging from agriculture to biopharmaceuticals. Episomal-based plastid engineering will allow precise single step metabolic engineering in plants enabling the installation of complex synthetic circuits with the ambitious goal of reaching similar efficiency and flexibility of to the state-of-the-art genetic engineering of prokaryotic systems. The prospect to design novel episomal systems for production of transplastomic marker-free plants will also improve biosafety for eventual release in agriculture.
Topics: Genetic Engineering; Plastids; Plants; Transgenes; Metabolic Engineering; DNA; Plants, Genetically Modified; Transformation, Genetic
PubMed: 37127835
DOI: 10.1007/s00299-023-03020-x -
Biochimica Et Biophysica Acta Sep 2015Progress in the field of regulated intramembrane proteolysis (RIP) in recent years has not surpassed plant biology. Nevertheless, reports on RIP in plants, and... (Review)
Review
Progress in the field of regulated intramembrane proteolysis (RIP) in recent years has not surpassed plant biology. Nevertheless, reports on RIP in plants, and especially in chloroplasts, are still scarce. Of the four different families of intramembrane proteases, only two have been linked to chloroplasts so far, rhomboids and site-2 proteases (S2Ps). The lack of chloroplast-located rhomboid proteases was associated with reduced fertility and aberrations in flower morphology, probably due to perturbations in jasmonic acid biosynthesis, which occurs in chloroplasts. Mutations in homologues of S2P resulted in chlorophyll deficiency and impaired chloroplast development, through a yet unknown mechanism. To date, the only known substrate of RIP in chloroplasts is a PHD transcription factor, located in the envelope. Upon proteolytic cleavage by an unknown protease, the soluble N-terminal domain of this protein is released from the membrane and relocates to the nucleus, where it activates the transcription of the ABA response gene ABI4. Continuing studies on these proteases and substrates, as well as identification of the genes responsible for different chloroplast mutant phenotypes, are expected to shed more light on the roles of intramembrane proteases in chloroplast biology.
Topics: Membrane Proteins; Peptide Hydrolases; Plastids; Proteolysis
PubMed: 25528366
DOI: 10.1016/j.bbabio.2014.12.006 -
Methods in Molecular Biology (Clifton,... 2018Plastids are semiautonomous organelles like mitochondria, and derive from a cyanobacterial ancestor that was engulfed by a host cell. During evolution, they have... (Review)
Review
Plastids are semiautonomous organelles like mitochondria, and derive from a cyanobacterial ancestor that was engulfed by a host cell. During evolution, they have recruited proteins originating from the nuclear genome, and only parts of their ancestral metabolic properties were conserved and optimized to limit functional redundancy with other cell compartments. Furthermore, large disparities in metabolic functions exist among various types of plastids, and the characterization of their various metabolic properties is far from being accomplished. In this review, we provide an overview of the main functions, known to be achieved by plastids or shared by plastids and other compartments of the cell. In short, plastids appear at the heart of all main plant functions.
Topics: Biological Evolution; Energy Metabolism; Plastids
PubMed: 29987715
DOI: 10.1007/978-1-4939-8654-5_5