A5043806031- Photosynthetic Processes and Mechanisms
- Porphyrin Metabolism and Disorders
- Plant Stress Responses and Tolerance
- Genomics and Phylogenetic Studies
- Plant Molecular Biology Research
- RNA and protein synthesis mechanisms
- Plant Gene Expression Analysis
- Light effects on plants
- Porphyrin and Phthalocyanine Chemistry
- Plant nutrient uptake and metabolism
- Metalloenzymes and iron-sulfur proteins
- Plant tissue culture and regeneration
- Enzyme Structure and Function
- Chromosomal and Genetic Variations
- Mitochondrial Function and Pathology
- Algal biology and biofuel production
- CRISPR and Genetic Engineering
- Plant Toxicity and Pharmacological Properties
- Plant biochemistry and biosynthesis
- GABA and Rice Research
- Microbial Community Ecology and Physiology
- Metal-Catalyzed Oxygenation Mechanisms
- Protist diversity and phylogeny
- Antioxidant Activity and Oxidative Stress
- Redox biology and oxidative stress
Humboldt-Universität zu Berlin
2012-2024
Adler
2023
Universität Hamburg
2012
Instituto de Biología Molecular y Celular de Plantas
2011
Consejo Superior de Investigaciones Científicas
2011
Universitat Politècnica de València
2011
Max Planck Institute of Molecular Plant Physiology
2011
Lovelace Respiratory Research Institute
2008
Humboldt State University
1999
Institut für Urheber- und Medienrecht
1999
In addition to the RNA polymerases (RNAPs) transcribing nuclear genes, eukaryotic cells also require RNAPs transcribe genes of mitochondrial genome and, in plants, chloroplast genome. The plant Arabidopsis thaliana was found contain two similar encoding RNAP from yeast and bacteriophages T7, T3, SP6. putative transit peptides were capable targeting fusion proteins mitochondria chloroplasts, respectively, vitro. results indicate that plants is a bacteriophage-type enzyme. A gene duplication...
Abstract Fruit of tomato (Solanum lycopersicum), like those from many species, have been characterized to undergo a shift partially photosynthetic truly heterotrophic metabolism. While there is plentiful evidence for functional photosynthesis in young fruit, the rates carbon assimilation rarely exceed dioxide release, raising question its role this tissue. Here, we describe generation and characterization lines exhibiting fruit-specific reduction expression glutamate 1-semialdehyde...
Significance Both posttranscriptional RNA editing and tetrapyrrole metabolism are important processes in land plants animals. A direct link between these two distinct programs had hitherto not been established. This study reveals an unexpected function for protoporphyrinogen IX oxidase 1 from model plant Arabidopsis thaliana regulating plastid through interacting with modulating the stability of multiple organellar factors. In addition to furthering our knowledge composition apparatus, this...
Developmental or metabolic changes in chloroplasts can have profound effects on the rest of plant cell. Such intracellular responses are associated with signals that originate and convey information their physiological status to nucleus, which leads large-scale gene expression (retrograde signaling). A screen designed identify components retrograde signaling resulted discovery so-called genomes uncoupled (gun) mutants. Genetic evidence suggests chloroplast protein GUN1 integrates derived...
5-Aminolevulinic acid (ALA) is the first committed substrate of tetrapyrrole biosynthesis and formed from glutamyl-tRNA by two enzymatic steps. Glutamyl-tRNA reductase (GluTR) as enzyme ALA synthesis encoded HEMA genes tightly regulated at transcriptional posttranslational levels. Here, we show that caseinolytic protease (Clp) adaptor ClpS1 ClpC1 chaperone well GluTR-binding protein (GBP) interact with N terminus GluTR Loss-of function mutants ClpR2 proteins increased stability, whereas...
5-Aminolevulinic acid (ALA) is the universal precursor for tetrapyrrole biosynthesis and synthesized in plants three enzymatic steps: ligation of glutamate (Glu) to tRNA(Glu) by glutamyl-tRNA synthetase, reduction activated Glu Glu-1-semialdehyde reductase (GluTR), transamination ALA 1-semialdehyde aminotransferase. formation controls metabolic flow into biosynthetic pathway. GluTR proposed be key regulatory enzyme that tightly controlled at transcriptional posttranslational levels. We...
Chlorophyll accumulation and chloroplast development are regulated at multiple levels during plant development. The paralogous LLM-domain B-GATA transcription factors GNC GNL contribute to chlorophyll biosynthesis formation in light-grown Arabidopsis thaliana seedlings. Whereas there is already ample knowledge about the transcriptional regulation of GNL, identity their downstream targets largely unclear. Here, we identified genes controlling greening directly GATAs by integrating data from...
Summary Co‐ordination of gene expression between the three genomes present in plastids, mitochondria and nucleus is crucial importance for plant cells. Previous studies revealed that white leaves albostrians ( Hordeum vulgare cv. Haisa) mutant, photosynthesis‐related plastid nuclear genes are expressed only at an extremely low level. The plastids this mutant lack ribosomes, photosynthetic activity have rudimentary membrane systems. Here we report on mitochondrial barley. Steady‐state RNA...
In higher plants, a small nuclear gene family encodes mitochondrial as well chloroplast RNA polymerases (RNAP) homologous to the bacteriophage T7-enzyme. The Arabidopsis genome contains three such RpoT genes, while in monocotyledonous plants only two copies have been found. Analysis of Nicotiana tabacum, natural allotetraploid, identified six different sequences. study progenitor species tobacco, N. sylvestris and tomentosiformis, uncovered that sequences represent orthologous sets each...
Although chloroplast genomes are small, the transcriptional machinery is very complex in plastids of higher plants. Plastidial genes plants transcribed by plastid-encoded (PEP) and nuclear-encoded RNA polymerases (NEP). The nuclear genome Arabidopsis contains two candidate for NEP, RpoTp RpoTmp, both coding phage-type polymerases. We have analyzed use PEP NEP promoters transgenic lines with altered activities insertion mutants lacking functional RpoTp. Low or activity resulted an albino...
Summary Fluorescent in blue light (FLU) is a negative regulator involved dark repression of 5‐aminolevulinic acid (ALA) synthesis and interacts with glutamyl‐tRNA reductase (GluTR), the rate‐limiting enzyme tetrapyrrole biosynthesis. In this study, we investigated FLU‘s regulatory function light‐exposed FLU‐overexpressing (FLUOE) Arabidopsis lines under fluctuating intensities wild‐type (WT) flu seedlings. FLUOE suppress ALA light, resulting reduced chlorophyll content, but more strongly low...
Summary Tetrapyrroles have essential functions as pigments and cofactors during plant growth development, the tetrapyrrole biosynthesis pathway is tightly controlled. Multiple organellar RNA editing factors (MORFs) are required for of a wide variety sites in chloroplasts mitochondria, but their biochemical properties remain elusive. Here, we uncovered roles chloroplast‐localized MORF2 MORF9 modulating embryogenesis Arabidopsis thaliana . The lack or reduced transcripts significantly affected...
Summary The recent identification of phage‐type RNA polymerases encoded in the nuclear genome higher plants has provided circumstantial evidence for functioning these transcription mitochondrial and plastid genomes, as demonstrated by sequence analysis vitro import experiments. To determine subcellular localization organellar planta , putative transit peptides RpoT;1 RpoT;3 from Arabidopsis thaliana RpoT Chenopodium album were fused to coding a green fluorescent protein (GFP). constructs...
Arabidopsis HEMA1 and HEMA2 encode glutamyl-tRNA reductase (GluTR) 1 2, the two isoforms of initial enzyme tetrapyrrole biosynthesis. is dominantly expressed in photosynthetic tissue, while shows low constitutive expression induced upon stress treatments. We introduce a new knockout mutant which grows only heterotrophically on MS (Murashige Skoog) medium at light, indicating that remaining GluTR2 does not sufficiently compensate for extensive needs metabolic precursors Chl. While hema1...
Abstract GATAs are evolutionarily conserved zinc‐finger transcription factors from eukaryotes. In plants, can be subdivided into four classes, A–D, based on their DNA‐binding domain, and further subclasses additional protein motifs. B‐GATAs with a so‐called leucine‐leucine‐methionine (LLM)‐domain already found in algae. angiosperms, the B‐GATA family is expanded to LLM‐ or HAN‐domain B‐GATAs. Both, domains of unknown biochemical function. Interestingly, liverwort Marchantia polymorpha moss...
Abstract All land plants encode 2 isoforms of protoporphyrinogen oxidase (PPO). While PPO1 is predominantly expressed in green tissues and its loss seedling-lethal Arabidopsis (Arabidopsis thaliana), the effects PPO2 deficiency have not been investigated detail. We identified ppo2 T-DNA insertion mutants from publicly available collections, one which (ppo2-2) a knock-out mutant. did result any obvious phenotype, substantial changes PPO activity were measured etiolated root tissues. However,...
Tetrapyrrole biosynthesis (TBS) is a dynamically and strictly regulated process. Disruptions in tetrapyrrole metabolism influence many aspects of plant physiology, including photosynthesis, programmed cell death (PCD), retrograde signaling, thus affecting growth development at multiple levels. However, the genetic molecular basis TBS not fully understood. We report here PCD8, newly identified thylakoid-localized protein encoded by an essential gene Arabidopsis. PCD8 knockdown causes necrotic...
Riboflavin serves as a precursor for flavocoenzymes (FMN and FAD) is essential all living organisms. The two committed enzymatic steps of riboflavin biosynthesis are performed in plants by bifunctional RIBA enzymes comprised GTP cyclohydrolase II (GCHII) 3,4-dihydroxy-2-butanone-4-phosphate synthase (DHBPS). Angiosperms share small gene family consisting three members. A reduction AtRIBA1 expression the Arabidopsis rfd1mutant RIBA1 antisense lines not complemented simultaneously expressed...
The synthesis of 5-aminolevulinic acid (ALA) determines adequate amounts metabolites for the tetrapyrrole biosynthetic pathway. Glutamyl-tRNA reductase (GluTR) catalyzes rate-limiting step ALA and was previously considered to be exclusively localized in chloroplast stroma light-exposed plants. To assess intraplastidic localization GluTR, we developed a fast separation protocol soluble membrane-bound proteins reassessed subplastidal allocation GluTR membrane fractions Arabidopsis plants grown...
During photoperiodic growth, the light-dependent nature of chlorophyll synthesis in angiosperms necessitates robust control production 5-aminolevulinic acid (ALA), rate-limiting step initial stage tetrapyrrole biosynthesis (TBS). We are interested dissecting post-translational this process, which suppresses ALA for dark-grown plants. Using biochemical approaches analysis Arabidopsis wild-type (WT) and mutant lines as well complementation lines, we show that heme-synthesizing ferrochelatase 2...