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Plant & Cell Physiology May 2024
Topics: Mitochondria; Plastids; Plants
PubMed: 38590035
DOI: 10.1093/pcp/pcae036 -
Current Opinion in Plant Biology Apr 2021Genetic approaches to modify starch in crops have been limited by our knowledge of starch biosynthesis. Recent advances in Arabidopsis have revealed key genetic... (Review)
Review
Genetic approaches to modify starch in crops have been limited by our knowledge of starch biosynthesis. Recent advances in Arabidopsis have revealed key genetic components determining the size, shape and number of granules in a plastid. This has opened the doors to new discoveries on granule initiation in crop species. In parallel, advances in genomic resources and gene editing technologies allow targeted manipulation of starch biosynthesis genes in isogenic crop backgrounds. Such technologies have been successfully deployed to alter starch composition, and can now be used to modify other starch traits. This will allow the complex relationships between starch structure and physicochemical properties to be elucidated, which will facilitate the rational manipulation of starches in crops.
Topics: Arabidopsis; Crops, Agricultural; Gene Editing; Plastids; Starch
PubMed: 33677239
DOI: 10.1016/j.pbi.2021.102013 -
Plant Biotechnology Journal Feb 2022In the age of synthetic biology, plastid engineering requires a nimble platform to introduce novel synthetic circuits in plants. While effective for integrating...
In the age of synthetic biology, plastid engineering requires a nimble platform to introduce novel synthetic circuits in plants. While effective for integrating relatively small constructs into the plastome, plastid engineering via homologous recombination of transgenes is over 30 years old. Here we show the design-build-test of a novel synthetic genome structure that does not disturb the native plastome: the 'mini-synplastome'. The mini-synplastome was inspired by dinoflagellate plastome organization, which is comprised of numerous minicircles residing in the plastid instead of a single organellar genome molecule. The first mini-synplastome in plants was developed in vitro to meet the following criteria: (i) episomal replication in plastids; (ii) facile cloning; (iii) predictable transgene expression in plastids; (iv) non-integration of vector sequences into the endogenous plastome; and (v) autonomous persistence in the plant over generations in the absence of exogenous selection pressure. Mini-synplastomes are anticipated to revolutionize chloroplast biotechnology, enable facile marker-free plastid engineering, and provide an unparalleled platform for one-step metabolic engineering in plants.
Topics: Genetic Engineering; Metabolic Engineering; Plants; Plastids; Synthetic Biology; Transgenes
PubMed: 34585834
DOI: 10.1111/pbi.13717 -
Cells Oct 2020GUN1 (genomes uncoupled 1), a chloroplast-localized pentatricopeptide repeat (PPR) protein with a C-terminal small mutS-related (SMR) domain, plays a central role in the... (Review)
Review
GUN1 (genomes uncoupled 1), a chloroplast-localized pentatricopeptide repeat (PPR) protein with a C-terminal small mutS-related (SMR) domain, plays a central role in the retrograde communication of chloroplasts with the nucleus. This flow of information is required for the coordinated expression of plastid and nuclear genes, and it is essential for the correct development and functioning of chloroplasts. Multiple genetic and biochemical findings indicate that GUN1 is important for protein homeostasis in the chloroplast; however, a clear and unified view of GUN1's role in the chloroplast is still missing. Recently, GUN1 has been reported to modulate the activity of the nucleus-encoded plastid RNA polymerase (NEP) and modulate editing of plastid RNAs upon activation of retrograde communication, revealing a major role of GUN1 in plastid RNA metabolism. In this opinion article, we discuss the recently identified links between plastid RNA metabolism and retrograde signaling by providing a new and extended concept of GUN1 activity, which integrates the multitude of functional genetic interactions reported over the last decade with its primary role in plastid transcription and transcript editing.
Topics: Gene Expression Regulation, Plant; Plant Proteins; Plastids; Protein Binding; RNA, Chloroplast; Stress, Physiological
PubMed: 33081381
DOI: 10.3390/cells9102307 -
Methods in Molecular Biology (Clifton,... 2024Plastids are semi-autonomous organelles like mitochondria and derive from a cyanobacterial ancestor that was engulfed by a host cell. During evolution, they have... (Review)
Review
Plastids are semi-autonomous 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: Plastids; Mitochondria
PubMed: 38502499
DOI: 10.1007/978-1-0716-3726-5_5 -
Trends in Plant Science Apr 2021N terminal protein α-acetylation (NTA) is a pervasive protein modification that has recently attracted renewed interest. Early studies on NTA were mostly conducted in... (Review)
Review
N terminal protein α-acetylation (NTA) is a pervasive protein modification that has recently attracted renewed interest. Early studies on NTA were mostly conducted in yeast and metazoans, providing a detailed portrait of the modification, which was indirectly applied to all eukaryotes. However, new findings originating from photosynthetic organisms have expanded our knowledge of this modification, revealing strong similarities as well as idiosyncratic features. Here, we review the most recent advances on NTA and its dedicated machinery in photosynthetic organisms. We discuss the cytosolic and unique plastid NTA machineries and their critical biological roles in development, stress responses, protein translocation, and stability. These new findings suggest that the multitasking plastid and cytosolic machineries evolved to support the specific needs of photoautotrophs.
Topics: Acetylation; Photosynthesis; Plastids; Protein Processing, Post-Translational
PubMed: 33384262
DOI: 10.1016/j.tplants.2020.11.012 -
Journal of Experimental Botany Nov 2022Plant seeds do not contain differentiated chloroplasts. Upon germination, the seedlings thus need to gain photoautotrophy before storage energies are depleted. This... (Review)
Review
Plant seeds do not contain differentiated chloroplasts. Upon germination, the seedlings thus need to gain photoautotrophy before storage energies are depleted. This requires the coordinated expression of photosynthesis genes encoded in nuclear and plastid genomes. Chloroplast biogenesis needs to be additionally coordinated with the light regulation network that controls seedling development. This coordination is achieved by nucleus to plastid signals called anterograde and plastid to nucleus signals termed retrograde. Retrograde signals sent from plastids during initial chloroplast biogenesis are also called biogenic signals. They have been recognized as highly important for proper chloroplast biogenesis and for seedling development. The molecular nature, transport, targets, and signalling function of biogenic signals are, however, under debate. Several studies disproved the involvement of a number of key components that were at the base of initial models of retrograde signalling. New models now propose major roles for a functional feedback between plastid and cytosolic protein homeostasis in signalling plastid dysfunction as well as the action of dually localized nucleo-plastidic proteins that coordinate chloroplast biogenesis with light-dependent control of seedling development. This review provides a survey of the developments in this research field, summarizes the unsolved questions, highlights several recent advances, and discusses potential new working modes.
Topics: Plastids; Chloroplasts; Genome, Plastid; Chloroplast Proteins; Photosynthesis
PubMed: 36002302
DOI: 10.1093/jxb/erac344 -
The New Phytologist Oct 2019Plastids evolved from a cyanobacterium that was engulfed by a heterotrophic eukaryotic host and became a stable organelle. Some of the resulting eukaryotic algae entered... (Review)
Review
Plastids evolved from a cyanobacterium that was engulfed by a heterotrophic eukaryotic host and became a stable organelle. Some of the resulting eukaryotic algae entered into a number of secondary endosymbioses with diverse eukaryotic hosts. These events had major consequences on the evolution and diversification of life on Earth. Although almost all plastid diversity derives from a single endosymbiotic event, the analysis of nuclear genomes of plastid-bearing lineages has revealed a mosaic origin of plastid-related genes. In addition to cyanobacterial genes, plastids recruited for their functioning eukaryotic proteins encoded by the host nucleus and also bacterial proteins of noncyanobacterial origin. Therefore, plastid proteins and plastid-localised metabolic pathways evolved by tinkering and using gene toolkits from different sources. This mixed heritage seems especially complex in secondary algae containing green plastids, the acquisition of which appears to have been facilitated by many previous acquisitions of red algal genes (the 'red carpet hypothesis').
Topics: Biological Evolution; Gene Expression Regulation; Gene Transfer, Horizontal; Photosynthesis; Plastids; Symbiosis
PubMed: 31135958
DOI: 10.1111/nph.15965 -
Nature Reviews. Microbiology Jun 2024
Topics: Organelles; Plastids
PubMed: 38658788
DOI: 10.1038/s41579-024-01053-x -
The New Phytologist Aug 2022Incongruent phylogenies have been widely observed between nuclear and plastid or mitochondrial genomes in terrestrial plants and animals. However, few studies have...
Incongruent phylogenies have been widely observed between nuclear and plastid or mitochondrial genomes in terrestrial plants and animals. However, few studies have examined these patterns in microalgae or the discordance between the two organelles. Here we investigated the nuclear-mitochondrial-plastid phylogenomic incongruence in Emiliania-Gephyrocapsa, a group of cosmopolitan calcifying phytoplankton with enormous populations and recent speciations. We assembled mitochondrial and plastid genomes of 27 strains from across global oceans and temperature regimes, and analyzed the phylogenomic histories of the three compartments using concatenation and coalescence methods. Six major clades with varying morphology and distribution are well recognized in the nuclear phylogeny, but such relationships are absent in the mitochondrial and plastid phylogenies, which also differ substantially from each other. The rampant phylogenomic discordance is due to a combination of organellar capture (introgression), organellar genome recombination, and incomplete lineage sorting of ancient polymorphic organellar genomes. Hybridization can lead to replacements of whole organellar genomes without introgression of nuclear genes and the two organelles are not inherited as a single cytoplasmic unit. This study illustrates the convoluted evolution and inheritance of organellar genomes in isogamous haplodiplontic microalgae and provides a window into the phylogenomic complexity of marine unicellular eukaryotes.
Topics: Animals; Genome, Mitochondrial; Genome, Plastid; Microalgae; Phylogeny; Plastids
PubMed: 35556250
DOI: 10.1111/nph.18219