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International Journal of Molecular... Feb 2021Eleven published articles (4 reviews, 7 research papers) are collected in the Special Issue entitled "Organelle Genetics in Plants." This selection of papers covers a...
Eleven published articles (4 reviews, 7 research papers) are collected in the Special Issue entitled "Organelle Genetics in Plants." This selection of papers covers a wide range of topics related to chloroplasts and plant mitochondria research: (i) organellar gene expression (OGE) and, more specifically, chloroplast RNA editing in soybean, mitochondria RNA editing, and intron splicing in soybean during nodulation, as well as the study of the roles of transcriptional and posttranscriptional regulation of OGE in plant adaptation to environmental stress; (ii) analysis of the nuclear integrants of mitochondrial DNA (NUMTs) or plastid DNA (NUPTs); (iii) sequencing and characterization of mitochondrial and chloroplast genomes; (iv) recent advances in plastid genome engineering. Here we summarize the main findings of these works, which represent the latest research on the genetics, genomics, and biotechnology of chloroplasts and mitochondria.
Topics: Crops, Agricultural; Genome, Mitochondrial; Plants; Plastids; RNA Editing
PubMed: 33672640
DOI: 10.3390/ijms22042104 -
Protoplasma Jan 2024
Topics: Plastids
PubMed: 38102506
DOI: 10.1007/s00709-023-01913-y -
The Plant Cell Feb 2023Chloroplasts produce singlet oxygen (1O2), which causes changes in nuclear gene expression through plastid-to-nucleus retrograde signaling to increase plant fitness....
Chloroplasts produce singlet oxygen (1O2), which causes changes in nuclear gene expression through plastid-to-nucleus retrograde signaling to increase plant fitness. However, the identity of this 1O2-triggered pathway remains unclear. Here, we identify mutations in GENOMES UNCOUPLED4 (GUN4) and GUN5 as suppressors of phytochrome-interacting factor1 (pif1) pif3 in regulating the photo-oxidative response in Arabidopsis thaliana. GUN4 and GUN5 specifically interact with EXECUTER1 (EX1) and EX2 in plastids, and this interaction is alleviated by treatment with Rose Bengal (RB) or white light. Impaired expression of GUN4, GUN5, EX1, or EX2 leads to insensitivity to excess light and overexpression of EX1 triggers photo-oxidative responses. Strikingly, upon light irradiation or RB treatment, EX1 transiently accumulates in the nucleus and the nuclear fraction of EX1 shows a similar molecular weight as the plastid-located protein. Point mutagenesis analysis indicated that nuclear localization of EX1 is required for its function. EX1 acts as a transcriptional co-activator and interacts with the transcription factors WRKY18 and WRKY40 to promote the expression of 1O2-responsive genes. This study suggests that EX1 may act in plastid-to-nucleus signaling and establishes a 1O2-triggered retrograde signaling pathway that allows plants adapt to changing light environments during chloroplast development.
Topics: Arabidopsis; Singlet Oxygen; Arabidopsis Proteins; Transcription Factors; Plastids; Signal Transduction; Chloroplasts; Mutation; Gene Expression Regulation, Plant; Intracellular Signaling Peptides and Proteins
PubMed: 36423342
DOI: 10.1093/plcell/koac330 -
The New Phytologist Mar 2021The chloroplast has recently emerged as pivotal to co-ordinating plant defence responses and as a target of plant pathogens. Beyond its central position in oxygenic... (Review)
Review
The chloroplast has recently emerged as pivotal to co-ordinating plant defence responses and as a target of plant pathogens. Beyond its central position in oxygenic photosynthesis and primary metabolism - key targets in the complex virulence strategies of diverse pathogens - the chloroplast integrates, decodes and responds to environmental signals. The capacity of chloroplasts to synthesize phytohormones and a diverse range of secondary metabolites, combined with retrograde and reactive oxygen signalling, provides exquisite flexibility to both perceive and respond to biotic stresses. These processes also represent a plethora of opportunities for pathogens to evolve strategies to directly or indirectly target 'chloroplast immunity'. This review covers the contribution of the chloroplast to pathogen associated molecular pattern and effector triggered immunity as well as systemic acquired immunity. We address phytohormone modulation of immunity and surmise how chloroplast-derived reactive oxygen species underpin chloroplast immunity through indirect evidence inferred from genetic modification of core chloroplast components and direct pathogen targeting of the chloroplast. We assess the impact of transcriptional reprogramming of nuclear-encoded chloroplast genes during disease and defence and look at future research challenges.
Topics: Chloroplasts; Pathogen-Associated Molecular Pattern Molecules; Plant Growth Regulators; Plant Immunity; Signal Transduction
PubMed: 33206379
DOI: 10.1111/nph.17076 -
Current Biology : CB Jun 2019Mitochondria, a nearly ubiquitous feature of eukaryotes, are derived from an ancient symbiosis. Despite billions of years of cooperative coevolution - in what is... (Review)
Review
Mitochondria, a nearly ubiquitous feature of eukaryotes, are derived from an ancient symbiosis. Despite billions of years of cooperative coevolution - in what is arguably the most important mutualism in the history of life - the persistence of mitochondrial genomes also creates conditions for genetic conflict with the nucleus. Because mitochondrial genomes are present in numerous copies per cell, they are subject to both within- and among-organism levels of selection. Accordingly, 'selfish' genotypes that increase their own proliferation can rise to high frequencies even if they decrease organismal fitness. It has been argued that uniparental (often maternal) inheritance of cytoplasmic genomes evolved to curtail such selfish replication by minimizing within-individual variation and, hence, within-individual selection. However, uniparental inheritance creates conditions for cytonuclear conflict over sex determination and sex ratio, as well as conditions for sexual antagonism when mitochondrial variants increase transmission by enhancing maternal fitness but have the side-effect of being harmful to males (i.e., 'mother's curse'). Here, we review recent advances in understanding selfish replication and sexual antagonism in the evolution of mitochondrial genomes and the mechanisms that suppress selfish interactions, drawing parallels and contrasts with other organelles (plastids) and bacterial endosymbionts that arose more recently. Although cytonuclear conflict is widespread across eukaryotes, it can be cryptic due to nuclear suppression, highly variable, and lineage-specific, reflecting the diverse biology of eukaryotes and the varying architectures of their cytoplasmic genomes.
Topics: Bacterial Physiological Phenomena; Biological Evolution; Eukaryota; Genome, Mitochondrial; Plastids; Symbiosis
PubMed: 31163164
DOI: 10.1016/j.cub.2019.03.020 -
The New Phytologist Sep 2021Endosymbiosis is a relationship between two organisms wherein one cell resides inside the other. This affiliation, when stable and beneficial for the 'host' cell, can... (Review)
Review
Endosymbiosis is a relationship between two organisms wherein one cell resides inside the other. This affiliation, when stable and beneficial for the 'host' cell, can result in massive genetic innovation with the foremost examples being the evolution of eukaryotic organelles, the mitochondria and plastids. Despite its critical evolutionary role, there is limited knowledge about how endosymbiosis is initially established and how host-endosymbiont biology is integrated. Here, we explore this issue, using as our model the rhizarian amoeba Paulinella, which represents an independent case of primary plastid origin that occurred c. 120 million yr ago. We propose the 'chassis and engine' model that provides a theoretical framework for understanding primary plastid endosymbiosis, potentially explaining why it is so rare.
Topics: Amoeba; Biological Evolution; Eukaryota; Phylogeny; Plastids; Symbiosis
PubMed: 34018613
DOI: 10.1111/nph.17478 -
The New Phytologist Jul 2019The chloroplast organelle in mesophyll cells of higher plants represents a sunlight-driven metabolic factory that eventually fuels life on our planet. Knowledge of the... (Review)
Review
The chloroplast organelle in mesophyll cells of higher plants represents a sunlight-driven metabolic factory that eventually fuels life on our planet. Knowledge of the ultrastructure and the dynamics of this unique organelle is essential to understanding its function in an ever-changing and challenging environment. Recent technological developments promise unprecedented insights into chloroplast architecture and its functionality. The review highlights these new methodical approaches and provides structural models based on recent findings about the plasticity of the thylakoid membrane system in response to different light regimes. Furthermore, the potential role of the lipid droplets plastoglobuli is discussed. It is emphasized that detailed structural insights are necessary on different levels ranging from molecules to entire membrane systems for a holistic understanding of chloroplast function.
Topics: Chloroplasts; Photosynthesis; Plants; Thylakoids
PubMed: 30721547
DOI: 10.1111/nph.15730 -
The Plant Cell Dec 2020
Topics: Chaperonins; Membrane Proteins; Thylakoids
PubMed: 33093142
DOI: 10.1105/tpc.20.00881 -
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 -
Redox Biology Oct 2020Oxylipins (compounds derived from the oxidation of polyunsaturated fatty acids) are essential in retrograde signaling emanating from plastids to the nucleus during plant... (Review)
Review
Oxylipins (compounds derived from the oxidation of polyunsaturated fatty acids) are essential in retrograde signaling emanating from plastids to the nucleus during plant developmental and stress responses. In this graphical review, we provide an overview of the chemical structure, biosynthesis and role of oxylipins, as both redox and hormonal signals, in controlling plant development and stress responses. We also briefly summarize current gaps in the understanding of the involvement of oxylipins in plastidial retrograde signaling to highlight future avenues for research.
Topics: Fatty Acids, Unsaturated; Oxylipins; Plants; Plastids; Signal Transduction
PubMed: 32979794
DOI: 10.1016/j.redox.2020.101717