TY - JOUR A1 - Ribeiro, Dimas M. A1 - Araujo, Wagner L. A1 - Fernie, Alisdair R. A1 - Schippers, Jos H. M. A1 - Müller-Röber, Bernd T1 - Translatome and metabolome effects triggered by gibberellins during rosette growth in Arabidopsis JF - Journal of experimental botany N2 - Although gibberellins (GAs) are well known for their growth control function, little is known about their effects on primary metabolism. Here the modulation of gene expression and metabolic adjustment in response to changes in plant (Arabidopsis thaliana) growth imposed on varying the gibberellin regime were evaluated. Polysomal mRNA populations were profiled following treatment of plants with paclobutrazol (PAC), an inhibitor of GA biosynthesis, and gibberellic acid (GA(3)) to monitor translational regulation of mRNAs globally. Gibberellin levels did not affect levels of carbohydrates in plants treated with PAC and/or GA(3). However, the tricarboxylic acid cycle intermediates malate and fumarate, two alternative carbon storage molecules, accumulated upon PAC treatment. Moreover, an increase in nitrate and in the levels of the amino acids was observed in plants grown under a low GA regime. Only minor changes in amino acid levels were detected in plants treated with GA(3) alone, or PAC plus GA(3). Comparison of the molecular changes at the transcript and metabolite levels demonstrated that a low GA level mainly affects growth by uncoupling growth from carbon availability. These observations, together with the translatome changes, reveal an interaction between energy metabolism and GA-mediated control of growth to coordinate cell wall extension, secondary metabolism, and lipid metabolism. KW - Gibberellin KW - growth KW - paclobutrazol KW - primary metabolism KW - translatome Y1 - 2012 U6 - https://doi.org/10.1093/jxb/err463 SN - 0022-0957 VL - 63 IS - 7 SP - 2769 EP - 2786 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Lu, Dandan A1 - Wang, Ting A1 - Persson, Staffan A1 - Müller-Röber, Bernd A1 - Schippers, Jos H. M. T1 - Transcriptional control of ROS homeostasis by KUODA1 regulates cell expansion during leaf development JF - Nature Communications N2 - The final size of an organism, or of single organs within an organism, depends on an intricate coordination of cell proliferation and cell expansion. Although organism size is of fundamental importance, the molecular and genetic mechanisms that control it remain far from understood. Here we identify a transcription factor, KUODA1 (KUA1), which specifically controls cell expansion during leaf development in Arabidopsis thaliana. We show that KUA1 expression is circadian regulated and depends on an intact clock. Furthermore, KUA1 directly represses the expression of a set of genes encoding for peroxidases that control reactive oxygen species (ROS) homeostasis in the apoplast. Disruption of KUA1 results in increased peroxidase activity and smaller leaf cells. Chemical or genetic interference with the ROS balance or peroxidase activity affects cell size in a manner consistent with the identified KUA1 function. Thus, KUA1 modulates leaf cell expansion and final organ size by controlling ROS homeostasis. Y1 - 2014 U6 - https://doi.org/10.1038/ncomms4767 SN - 2041-1723 VL - 5 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Schmidt, Romy A1 - Schippers, Jos H. M. A1 - Welker, Annelie A1 - Mieulet, Delphine A1 - Guiderdoni, Emmanuel A1 - Müller-Röber, Bernd T1 - Transcription factor OsHsfC1b regulates salt tolerance and development in Oryza sativa ssp japonica JF - AoB PLANTS N2 - Background and aims Salt stress leads to attenuated growth and productivity in rice. Transcription factors like heat shock factors (HSFs) represent central regulators of stress adaptation. Heat shock factors of the classes A and B are well established as regulators of thermal and non-thermal stress responses in plants; however, the role of class C HSFs is unknown. Here we characterized the function of the OsHsfC1b (Os01g53220) transcription factor from rice. Methodology We analysed the expression of OsHsfC1b in the rice japonica cultivars Dongjin and Nipponbare exposed to salt stress as well as after mannitol, abscisic acid (ABA) and H2O2 treatment. For functional characterization of OsHsfC1b, we analysed the physiological response of a T-DNA insertion line (hsfc1b) and two artificial micro-RNA (amiRNA) knock-down lines to salt, mannitol and ABA treatment. In addition, we quantified the expression of small Heat Shock Protein (sHSP) genes and those related to signalling and ion homeostasis by quantitative real-time polymerase chain reaction in roots exposed to salt. The subcellular localization of OsHsfC1b protein fused to green fluorescent protein (GFP) was determined in Arabidopsis mesophyll cell protoplasts. Principal results Expression of OsHsfC1b was induced by salt, mannitol and ABA, but not by H2O2. Impaired function of OsHsfC1b in the hsfc1b mutant and the amiRNA lines led to decreased salt and osmotic stress tolerance, increased sensitivity to ABA, and temporal misregulation of salt-responsive genes involved in signalling and ion homeostasis. Furthermore, sHSP genes showed enhanced expression in knock-down plants under salt stress. We observed retarded growth of hsfc1b and knock-down lines in comparison with control plants under non-stress conditions. Transient expression of OsHsfC1b fused to GFP in protoplasts revealed nuclear localization of the transcription factor. Conclusions OsHsfC1b plays a role in ABA-mediated salt stress tolerance in rice. Furthermore, OsHsfC1b is involved in the response to osmotic stress and is required for plant growth under non-stress conditions. Y1 - 2012 U6 - https://doi.org/10.1093/aobpla/pls011 SN - 2041-2851 IS - 3 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Vogt, Julia H. M. A1 - Schippers, Jos H. M. T1 - Setting the PAS, the role of circadian PAS domain proteins during environmental adaptation in plants JF - Frontiers in plant science N2 - The per-ARNT-sim (PAS) domain represents an ancient protein module that can be found across all kingdoms of life. The domain functions as a sensing unit for a diverse array of signals, including molecular oxygen, small metabolites, and light. In plants, several PAS domain-containing proteins form an integral part of the circadian clock and regulate responses to environmental change. Moreover, these proteins function in pathways that control development and plant stress adaptation responses. Here, we discuss the role of PAS domain-containing proteins in anticipation, and adaptation to environmental changes in plants. KW - PAS domain KW - circadian clock KW - signal transduction KW - environmental stress response KW - growth adaptation Y1 - 2015 U6 - https://doi.org/10.3389/fpls.2015.00513 SN - 1664-462X VL - 6 PB - Frontiers Research Foundation CY - Lausanne ER - TY - GEN A1 - Vogt, Julia H. M. A1 - Schippers, Jos H. M. T1 - Setting the PAS, the role of circadian PAS domain proteins during environmental adaptation in plants T2 - Frontiers in plant science N2 - The per-ARNT-sim (PAS) domain represents an ancient protein module that can be found across all kingdoms of life. The domain functions as a sensing unit for a diverse array of signals, including molecular oxygen, small metabolites, and light. In plants, several PAS domain-containing proteins form an integral part of the circadian clock and regulate responses to environmental change. Moreover, these proteins function in pathways that control development and plant stress adaptation responses. Here, we discuss the role of PAS domain-containing proteins in anticipation, and adaptation to environmental changes in plants. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 430 KW - PAS domain KW - circadian clock KW - signal transduction KW - environmental stress response KW - growth adaptation Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-406492 ER - TY - JOUR A1 - Schmidt, Romy A1 - Schippers, Jos H. M. A1 - Mieulet, Delphine A1 - Watanabe, Mutsumi A1 - Hoefgen, Rainer A1 - Guiderdoni, Emmanuel A1 - Müller-Röber, Bernd T1 - Salt-Rresponsive ERF1 is a negative regulator of grain filling and gibberellin-mediated seedling establishment in rice JF - Molecular plant N2 - Grain quality is an important agricultural trait that is mainly determined by grain size and composition. Here, we characterize the role of the rice transcription factor (TF) SALT-RESPONSIVE ERF1 (SERF1) during grain development. Through genome-wide expression profiling and chromatin immunoprecipitation, we found that SERF1 directly regulates RICE PROLAMIN-BOX BINDING FACTOR (RPBF), a TF that functions as a positive regulator of grain filling. Loss of SERF1 enhances RPBF expression resulting in larger grains with increased starch content, while SERF1 overexpression represses RPBF resulting in smaller grains. Consistently, during grain filling, starch biosynthesis genes such as GRANULE-BOUND STARCH SYNTHASEI (GBSSI), STARCH SYNTHASEI (SSI), SSIIIa, and ADP-GLUCOSE PYROPHOSPHORYLASE LARGE SUBUNIT2 (AGPL2) are up-regulated in SERF1 knockout grains. Moreover, SERF1 is a direct upstream regulator of GBSSI. In addition, SERF1 negatively regulates germination by controlling RPBF expression, which mediates the gibberellic acid (GA)-induced expression of RICE AMYLASE1A (RAmy1A). Loss of SERF1 results in more rapid seedling establishment, while SERF1 overexpression has the opposite effect. Our study reveals that SERF1 represents a negative regulator of grain filling and seedling establishment by timing the expression of RPBF. KW - RPBF KW - rice KW - grain filling KW - germination KW - SERF1 KW - gibberellic acid Y1 - 2014 U6 - https://doi.org/10.1093/mp/sst131 SN - 1674-2052 SN - 1752-9867 VL - 7 IS - 2 SP - 404 EP - 421 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Schmidt, Romy A1 - Mieulet, Delphine A1 - Hubberten, Hans-Michael A1 - Obata, Toshihiro A1 - Höfgen, Rainer A1 - Fernie, Alisdair R. A1 - Fisahn, Joachim A1 - Segundo, Blanca San A1 - Guiderdoni, Emmanuel A1 - Schippers, Jos H. M. A1 - Müller-Röber, Bernd T1 - Salt-responsive ERF1 regulates reactive oxygen species-dependent signaling during the initial response to salt stress in rice JF - The plant cell N2 - Early detection of salt stress is vital for plant survival and growth. Still, the molecular processes controlling early salt stress perception and signaling are not fully understood. Here, we identified SALT-RESPONSIVE ERF1 (SERF1), a rice (Oryza sativa) transcription factor (TF) gene that shows a root-specific induction upon salt and hydrogen peroxide (H2O2) treatment. Loss of SERF1 impairs the salt-inducible expression of genes encoding members of a mitogen-activated protein kinase (MAPK) cascade and salt tolerance-mediating TFs. Furthermore, we show that SERF1-dependent genes are H2O2 responsive and demonstrate that SERF1 binds to the promoters of MAPK KINASE KINASE6 (MAP3K6), MAPK5, DEHYDRATION-RESPONSIVE ELEMENT BINDING2A (DREB2A), and ZINC FINGER PROTEIN179 (ZFP179) in vitro and in vivo. SERF1 also directly induces its own gene expression. In addition, SERF1 is a phosphorylation target of MAPK5, resulting in enhanced transcriptional activity of SERF1 toward its direct target genes. In agreement, plants deficient for SERF1 are more sensitive to salt stress compared with the wild type, while constitutive overexpression of SERF1 improves salinity tolerance. We propose that SERF1 amplifies the reactive oxygen species-activated MAPK cascade signal during the initial phase of salt stress and translates the salt-induced signal into an appropriate expressional response resulting in salt tolerance. Y1 - 2013 U6 - https://doi.org/10.1105/tpc.113.113068 SN - 1040-4651 VL - 25 IS - 6 SP - 2115 EP - 2131 PB - American Society of Plant Physiologists CY - Rockville ER - TY - JOUR A1 - Wang, Ting A1 - Tohge, Takayuki A1 - Ivakov, Alexander A1 - Müller-Röber, Bernd A1 - Fernie, Alisdair R. A1 - Mutwil, Marek A1 - Schippers, Jos H. M. A1 - Persson, Staffan T1 - Salt-Related MYB1 Coordinates Abscisic Acid Biosynthesis and Signaling during Salt Stress in Arabidopsis JF - Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants N2 - Abiotic stresses, such as salinity, cause global yield loss of all major crop plants. Factors and mechanisms that can aid in plant breeding for salt stress tolerance are therefore of great importance for food and feed production. Here, we identified a MYB-like transcription factor, Salt-Related MYB1 (SRM1), that negatively affects Arabidopsis (Arabidopsis thaliana) seed germination under saline conditions by regulating the levels of the stress hormone abscisic acid (ABA). Accordingly, several ABA biosynthesis and signaling genes act directly downstream of SRM1, including SALT TOLERANT1/NINE-CIS-EPOXYCAROTENOID DIOXYGENASE3, RESPONSIVE TO DESICCATION26, and Arabidopsis NAC DOMAIN CONTAINING PROTEIN19. Furthermore, SRM1 impacts vegetative growth and leaf shape. We show that SRM1 is an important transcriptional regulator that directly targets ABA biosynthesis and signaling-related genes and therefore may be regarded as an important regulator of ABA-mediated salt stress tolerance. Y1 - 2015 U6 - https://doi.org/10.1104/pp.15.00962 SN - 0032-0889 SN - 1532-2548 VL - 169 IS - 2 SP - 1027 EP - + PB - American Society of Plant Physiologists CY - Rockville ER - TY - JOUR A1 - Schippers, Jos H. M. A1 - Nguyen, Hung M. A1 - Lu, Dandan A1 - Schmidt, Romy A1 - Müller-Röber, Bernd T1 - ROS homeostasis during development: an evolutionary conserved strategy JF - Cellular and molecular life sciences N2 - The balance between cellular proliferation and differentiation is a key aspect of development in multicellular organisms. Recent studies on Arabidopsis roots revealed distinct roles for different reactive oxygen species (ROS) in these processes. Modulation of the balance between ROS in proliferating cells and elongating cells is controlled at least in part at the transcriptional level. The effect of ROS on proliferation and differentiation is not specific for plants but appears to be conserved between prokaryotic and eukaryotic life forms. The ways in which ROS is received and how it affects cellular functioning is discussed from an evolutionary point of view. The different redox-sensing mechanisms that evolved ultimately result in the activation of gene regulatory networks that control cellular fate and decision-making. This review highlights the potential common origin of ROS sensing, indicating that organisms evolved similar strategies for utilizing ROS during development, and discusses ROS as an ancient universal developmental regulator. KW - Evolution KW - Reactive oxygen species KW - Development Y1 - 2012 U6 - https://doi.org/10.1007/s00018-012-1092-4 SN - 1420-682X VL - 69 IS - 19 SP - 3245 EP - 3257 PB - Springer CY - Basel ER - TY - JOUR A1 - Lai, Alvina G. A1 - Denton-Giles, Matthew A1 - Müller-Röber, Bernd A1 - Schippers, Jos H. M. A1 - Dijkwel, Paul P. T1 - Positional information resolves structural variations and uncovers an evolutionarily divergent genetic locus in accessions of arabidopsis thaliana JF - Genome biology and evolution N2 - Genome sequencing of closely related individuals has yielded valuable insights that link genome evolution to phenotypic variations. However, advancement in sequencing technology has also led to an escalation in the number of poor quality-drafted genomes assembled based on reference genomes that can have highly divergent or haplotypic regions. The self-fertilizing nature of Arabidopsis thaliana poses an advantage to sequencing projects because its genome is mostly homozygous. To determine the accuracy of an Arabidopsis drafted genome in less conserved regions, we performed a resequencing experiment on a similar to 371-kb genomic interval in the Landsberg erecta (Ler-0) accession. We identified novel structural variations (SVs) between Ler-0 and the reference accession Col-0 using a long-range polymerase chain reaction approach to generate an Illumina data set that has positional information, that is, a data set with reads that map to a known location. Positional information is important for accurate genome assembly and the resolution of SVs particularly in highly duplicated or repetitive regions. Sixty-one regions with misassembly signatures were identified from the Ler-0 draft, suggesting the presence of novel SVs that are not represented in the draft sequence. Sixty of those were resolved by iterative mapping using our data set. Fifteen large indels (> 100 bp) identified from this study were found to be located either within protein-coding regions or upstream regulatory regions, suggesting the formation of novel alleles or altered regulation of existing genes in Ler-0. We propose future genome-sequencing experiments to follow a clone-based approach that incorporates positional information to ultimately reveal haplotype-specific differences between accessions. KW - haplotype KW - allelic variants KW - drafted genomes KW - genome partitioning KW - comparative genomics Y1 - 2011 U6 - https://doi.org/10.1093/gbe/evr038 SN - 1759-6653 VL - 3 IS - 1-2 SP - 627 EP - 640 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Zhao, Liming A1 - Xia, Yan A1 - Wu, Xiao-Yuan A1 - Schippers, Jos H. M. A1 - Jing, Hai-Chun T1 - Phenotypic analysis and molecular markers of leaf senescence JF - Plant Senescence: Methods and Protocols N2 - The process of leaf senescence consists of the final stage of leaf development. It has evolved as a mechanism to degrade macromolecules and micronutrients and remobilize them to other developing parts of the plant; hence it plays a central role for the survival of plants and crop production. During senescence, a range of physiological, morphological, cellular, and molecular events occur, which are generally referred to as the senescence syndrome that includes several hallmarks such as visible yellowing, loss of chlorophyll and water content, increase of ion leakage and cell death, deformation of chloroplast and cell structure, as well as the upregulation of thousands of so-called senescence-associated genes (SAGs) and downregulation of photosynthesis-associated genes (PAGs). This chapter is devoted to methods characterizing the onset and progression of leaf senescence at the morphological, physiological, cellular, and molecular levels. Leaf senescence normally progresses in an age-dependent manner but is also induced prematurely by a variety of environmental stresses in plants. Focused on the hallmarks of the senescence syndrome, a series of protocols is described to asses quantitatively the senescence process caused by developmental cues or environmental perturbations. We first briefly describe the senescence process, the events associated with the senescence syndrome, and the theories and methods to phenotype senescence. Detailed protocols for monitoring senescence in planta and in vitro, using the whole plant and the detached leaf, respectively, are presented. For convenience, most of the protocols use the model plant species Arabidopsis and rice, but they can be easily extended to other plants. KW - Leaf senescence KW - Visible yellowing KW - Chlorophyll KW - Ion leakage KW - Cell death KW - Senescence-associated genes (SAGs) KW - Arabidopsis KW - Rice Y1 - 2018 SN - 978-1-4939-7672-0 SN - 978-1-4939-7670-6 U6 - https://doi.org/10.1007/978-1-4939-7672-0_3 SN - 1064-3745 SN - 1940-6029 VL - 1744 SP - 35 EP - 48 PB - Humana Press Inc. CY - Totowa ER - TY - JOUR A1 - Schmidt, Romy A1 - Schippers, Jos H. M. A1 - Mieulet, Delphine A1 - Obata, Toshihiro A1 - Fernie, Alisdair R. A1 - Guiderdoni, Emmanuel A1 - Müller-Röber, Bernd T1 - Multipass, a rice R2R3-type MYB transcription factor, regulates adaptive growth by integrating multiple hormonal pathways JF - The plant journal N2 - Growth regulation is an important aspect of plant adaptation during environmental perturbations. Here, the role of MULTIPASS (OsMPS), an R2R3-type MYB transcription factor of rice, was explored. OsMPS is induced by salt stress and expressed in vegetative and reproductive tissues. Over-expression of OsMPS reduces growth under non-stress conditions, while knockdown plants display increased biomass. OsMPS expression is induced by abscisic acid and cytokinin, but is repressed by auxin, gibberellin and brassinolide. Growth retardation caused by OsMPS over-expression is partially restored by auxin application. Expression profiling revealed that OsMPS negatively regulates the expression of EXPANSIN (EXP) and cell-wall biosynthesis as well as phytohormone signaling genes. Furthermore, the expression of OsMPS-dependent genes is regulated by auxin, cytokinin and abscisic acid. Moreover, we show that OsMPS is a direct upstream regulator of OsEXPA4, OsEXPA8, OsEXPB2, OsEXPB3, OsEXPB6 and the endoglucanase genes OsGLU5 and OsGLU14. The multiple responses of OsMPS and its target genes to various hormones suggest an integrative function of OsMPS in the cross-talk between phytohormones and the environment to regulate adaptive growth. KW - development KW - expansin KW - transcription KW - Oryza sativa KW - hormone KW - abiotic stress Y1 - 2013 U6 - https://doi.org/10.1111/tpj.12286 SN - 0960-7412 SN - 1365-313X VL - 76 IS - 2 SP - 258 EP - 273 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Gechev, Tsanko S. A1 - Benina, Maria A1 - Obata, Toshihiro A1 - Tohge, Takayuki A1 - Neerakkal, Sujeeth A1 - Minkov, Ivan A1 - Hille, Jacques A1 - Temanni, Mohamed-Ramzi A1 - Marriott, Andrew S. A1 - Bergström, Ed A1 - Thomas-Oates, Jane A1 - Antonio, Carla A1 - Müller-Röber, Bernd A1 - Schippers, Jos H. M. A1 - Fernie, Alisdair R. A1 - Toneva, Valentina T1 - Molecular mechanisms of desiccation tolerance in the resurrection glacial relic Haberlea rhodopensis JF - Cellular and molecular life sciences N2 - Haberlea rhodopensis is a resurrection plant with remarkable tolerance to desiccation. Haberlea exposed to drought stress, desiccation, and subsequent rehydration showed no signs of damage or severe oxidative stress compared to untreated control plants. Transcriptome analysis by next-generation sequencing revealed a drought-induced reprogramming, which redirected resources from growth towards cell protection. Repression of photosynthetic and growth-related genes during water deficiency was concomitant with induction of transcription factors (members of the NAC, NF-YA, MADS box, HSF, GRAS, and WRKY families) presumably acting as master switches of the genetic reprogramming, as well as with an upregulation of genes related to sugar metabolism, signaling, and genes encoding early light-inducible (ELIP), late embryogenesis abundant (LEA), and heat shock (HSP) proteins. At the same time, genes encoding other LEA, HSP, and stress protective proteins were constitutively expressed at high levels even in unstressed controls. Genes normally involved in tolerance to salinity, chilling, and pathogens were also highly induced, suggesting a possible cross-tolerance against a number of abiotic and biotic stress factors. A notable percentage of the genes highly regulated in dehydration and subsequent rehydration were novel, with no sequence homology to genes from other plant genomes. Additionally, an extensive antioxidant gene network was identified with several gene families possessing a greater number of antioxidant genes than most other species with sequenced genomes. Two of the transcripts most abundant during all conditions encoded catalases and five more catalases were induced in water-deficient samples. Using the pharmacological inhibitor 3-aminotriazole (AT) to compromise catalase activity resulted in increased sensitivity to desiccation. Metabolome analysis by GC or LC-MS revealed accumulation of sucrose, verbascose, spermidine, and gamma-aminobutyric acid during drought, as well as particular secondary metabolites accumulating during rehydration. This observation, together with the complex antioxidant system and the constitutive expression of stress protective genes suggests that both constitutive and inducible mechanisms contribute to the extreme desiccation tolerance of H. rhodopensis. KW - Antioxidant genes KW - Catalase KW - Desiccation tolerance KW - Drought stress KW - Metabolome analysis KW - Resurrection plants Y1 - 2013 U6 - https://doi.org/10.1007/s00018-012-1155-6 SN - 1420-682X VL - 70 IS - 4 SP - 689 EP - 709 PB - Springer CY - Basel ER - TY - JOUR A1 - Lai, Alvina Grace A1 - Doherty, Colleen J. A1 - Müller-Röber, Bernd A1 - Kay, Steve A. A1 - Schippers, Jos H. M. A1 - Dijkwel, Paul P. T1 - CIRCADIAN CLOCK-ASSOCIATED 1 regulates ROS homeostasis and oxidative stress responses JF - Proceedings of the National Academy of Sciences of the United States of America N2 - Organisms have evolved endogenous biological clocks as internal timekeepers to coordinate metabolic processes with the external environment. Here, we seek to understand the mechanism of synchrony between the oscillator and products of metabolism known as Reactive Oxygen Species (ROS) in Arabidopsis thaliana. ROS-responsive genes exhibit a time-of-day-specific phase of expression under diurnal and circadian conditions, implying a role of the circadian clock in transcriptional regulation of these genes. Hydrogen peroxide production and scavenging also display time-of-day phases. Mutations in the core-clock regulator, CIRCADIAN CLOCK ASSOCIATED 1 (CCA1), affect the transcriptional regulation of ROS-responsive genes, ROS homeostasis, and tolerance to oxidative stress. Mis-expression of EARLY FLOWERING 3, LUX ARRHYTHMO, and TIMING OF CAB EXPRESSION 1 affect ROS production and transcription, indicating a global effect of the clock on the ROS network. We propose CCA1 as a master regulator of ROS homeostasis through association with the Evening Element in promoters of ROS genes in vivo to coordinate time-dependent responses to oxidative stress. We also find that ROS functions as an input signal that affects the transcriptional output of the clock, revealing an important link between ROS signaling and circadian output. Temporal coordination of ROS signaling by CCA1 and the reciprocal control of circadian output by ROS reveal a mechanistic link that allows plants to master oxidative stress responses. KW - redox homeostasis KW - transcriptional coordination Y1 - 2012 U6 - https://doi.org/10.1073/pnas.1209148109 SN - 0027-8424 VL - 109 IS - 42 SP - 17129 EP - 17134 PB - National Acad. of Sciences CY - Washington ER - TY - JOUR A1 - Nguyen, Hung M. A1 - Schippers, Jos H. M. A1 - Goni-Ramos, Oscar A1 - Christoph, Mathias P. A1 - Dortay, Hakan A1 - van der Hoorn, Renier A. L. A1 - Müller-Röber, Bernd T1 - An upstream regulator of the 26S proteasome modulates organ size in Arabidopsis thaliana JF - The plant journal N2 - In both animal and plant kingdoms, body size is a fundamental but still poorly understood attribute of biological systems. Here we report that the Arabidopsis NAC transcription factor Regulator of Proteasomal Gene Expression' (RPX) controls leaf size by positively modulating proteasome activity. We further show that the cis-element recognized by RPX is evolutionarily conserved between higher plant species. Upon over-expression of RPX, plants exhibit reduced growth, which may be reversed by a low concentration of the pharmacological proteasome inhibitor MG132. These data suggest that the rate of protein turnover during growth is a critical parameter for determining final organ size. KW - Arabidopsis thaliana KW - organ size KW - evolution KW - leaf development KW - proteasome KW - gene regulatory network Y1 - 2013 U6 - https://doi.org/10.1111/tpj.12097 SN - 0960-7412 VL - 74 IS - 1 SP - 25 EP - 36 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Ribeiro, Dimas M. A1 - Araujo, Wagner L. A1 - Fernie, Alisdair R. A1 - Schippers, Jos H. M. A1 - Müller-Röber, Bernd T1 - Action of Gibberellins on growth and metabolism of arabidopsis plants Associated with high concentration of carbon dioxide JF - Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants N2 - Although the positive effect of elevated CO2 concentration [CO2] on plant growth is well known, it remains unclear whether global climate change will positively or negatively affect crop yields. In particular, relatively little is known about the role of hormone pathways in controlling the growth responses to elevated [CO2]. Here, we studied the impact of elevated [CO2] on plant biomass and metabolism in Arabidopsis (Arabidopsis thaliana) in relation to the availability of gibberellins (GAs). Inhibition of growth by the GA biosynthesis inhibitor paclobutrazol (PAC) at ambient [CO2] (350 mu mol CO2 mol(-1)) was reverted by elevated [CO2] (750 mu mol CO2 mol(-1)). Thus, we investigated the metabolic adjustment and modulation of gene expression in response to changes in growth of plants imposed by varying the GA regime in ambient and elevated [CO2]. In the presence of PAC (low-GA regime), the activities of enzymes involved in photosynthesis and inorganic nitrogen assimilation were markedly increased at elevated [CO2], whereas the activities of enzymes of organic acid metabolism were decreased. Under ambient [CO2], nitrate, amino acids, and protein accumulated upon PAC treatment; however, this was not the case when plants were grown at elevated [CO2]. These results suggest that only under ambient [CO2] is GA required for the integration of carbohydrate and nitrogen metabolism underlying optimal biomass determination. Our results have implications concerning the action of the Green Revolution genes in future environmental conditions. Y1 - 2012 U6 - https://doi.org/10.1104/pp.112.204842 SN - 0032-0889 VL - 160 IS - 4 SP - 1781 EP - 1794 PB - American Society of Plant Physiologists CY - Rockville ER - TY - JOUR A1 - Shirzadian-Khorramabad, Reza A1 - Jing, Hai-Chun A1 - Everts, Gerja E. A1 - Schippers, Jos H. M. A1 - Hille, Jacques A1 - Dijkwel, Paul P. T1 - A mutation in the cytosolic O-acetylserine (thiol) lyase induces a genome-dependent early leaf death phenotype in Arabidopsis N2 - Background: Cysteine is a component in organic compounds including glutathione that have been implicated in the adaptation of plants to stresses. O-acetylserine (thiol) lyase (OAS-TL) catalyses the final step of cysteine biosynthesis. OAS-TL enzyme isoforms are localised in the cytoplasm, the plastids and mitochondria but the contribution of individual OAS-TL isoforms to plant sulphur metabolism has not yet been fully clarified. Results: The seedling lethal phenotype of the Arabidopsis onset of leaf death3-1 (old3-1) mutant is due to a point mutation in the OAS-A1 gene, encoding the cytosolic OAS-TL. The mutation causes a single amino acid substitution from Gly(162) to Glu(162), abolishing old3-1 OAS-TL activity in vitro. The old3-1 mutation segregates as a monogenic semidominant trait when backcrossed to its wild type accession Landsberg erecta (Ler-0) and the Di-2 accession. Consistent with its semi- dominant behaviour, wild type Ler-0 plants transformed with the mutated old3-1 gene, displayed the early leaf death phenotype. However, the old3-1 mutation segregates in an 11: 4: 1 (wild type: semi-dominant: mutant) ratio when backcrossed to the Colombia-0 and Wassilewskija accessions. Thus, the early leaf death phenotype depends on two semi- dominant loci. The second locus that determines the old3-1 early leaf death phenotype is referred to as odd-ler (for old3 determinant in the Ler accession) and is located on chromosome 3. The early leaf death phenotype is temperature dependent and is associated with increased expression of defence-response and oxidative-stress marker genes. Independent of the presence of the odd-ler gene, OAS-A1 is involved in maintaining sulphur and thiol levels and is required for resistance against cadmium stress. Conclusions: The cytosolic OAS-TL is involved in maintaining organic sulphur levels. The old3-1 mutation causes genome-dependent and independent phenotypes and uncovers a novel function for the mutated OAS- TL in cell death regulation. Y1 - 2010 UR - http://www.biomedcentral.com/1471-2229/ U6 - https://doi.org/10.1186/1471-2229-10-80 SN - 1471-2229 ER - TY - GEN A1 - Shirzadian-Khorramabad, Reza A1 - Jing, Hai-Chun A1 - Everts, Gerja E. A1 - Schippers, Jos H. M. A1 - Hille, Jacques A1 - Dijkwel, Paul P. T1 - A mutation in the cytosolic O-acetylserine (thiol) lyase induces a genome-dependent early leaf death phenotype in Arabidopsis T2 - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe N2 - Background: Cysteine is a component in organic compounds including glutathione that have been implicated in the adaptation of plants to stresses. O-acetylserine (thiol) lyase (OAS-TL) catalyses the final step of cysteine biosynthesis. OAS-TL enzyme isoforms are localised in the cytoplasm, the plastids and mitochondria but the contribution of individual OAS-TL isoforms to plant sulphur metabolism has not yet been fully clarified. Results: The seedling lethal phenotype of the Arabidopsis onset of leaf death3-1 (old3-1) mutant is due to a point mutation in the OAS-A1 gene, encoding the cytosolic OAS-TL. The mutation causes a single amino acid substitution from Gly(162) to Glu(162), abolishing old3-1 OAS-TL activity in vitro. The old3-1 mutation segregates as a monogenic semidominant trait when backcrossed to its wild type accession Landsberg erecta (Ler-0) and the Di-2 accession. Consistent with its semi-dominant behaviour, wild type Ler-0 plants transformed with the mutated old3-1 gene, displayed the early leaf death phenotype. However, the old3-1 mutation segregates in an 11: 4: 1 (wild type: semi-dominant: mutant) ratio when backcrossed to the Colombia-0 and Wassilewskija accessions. Thus, the early leaf death phenotype depends on two semi-dominant loci. The second locus that determines the old3-1 early leaf death phenotype is referred to as odd-ler (for old3 determinant in the Ler accession) and is located on chromosome 3. The early leaf death phenotype is temperature dependent and is associated with increased expression of defence-response and oxidative-stress marker genes. Independent of the presence of the odd-ler gene, OAS-A1 is involved in maintaining sulphur and thiol levels and is required for resistance against cadmium stress. Conclusions: The cytosolic OAS-TL is involved in maintaining organic sulphur levels. The old3-1 mutation causes genome-dependent and independent phenotypes and uncovers a novel function for the mutated OAS-TL in cell death regulation. KW - acyltransferase gene family KW - cysteine synthase complex KW - map-based cloning KW - serine acetyltransferase KW - o-acetylserine(thiol)lyase gene KW - amino-acids KW - glutathione homeostasis KW - functional-analysis KW - sulfur metabolism KW - cadmium tolerance Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427574 SN - 1866-8372 IS - 833 ER - TY - JOUR A1 - Benina, Maria A1 - Ribeiro, Dimas Mendes A1 - Gechev, Tsanko S. A1 - Müller-Röber, Bernd A1 - Schippers, Jos H. M. T1 - A cell type-specific view on the translation of mRNAs from ROS-responsive genes upon paraquat treatment of Arabidopsis thaliana leaves JF - Plant, cell & environment : cell physiology, whole-plant physiology, community physiology N2 - Oxidative stress causes dramatic changes in the expression levels of many genes. The formation of a functional protein through successful mRNA translation is central to a coordinated cellular response. To what extent the response towards reactive oxygen species (ROS) is regulated at the translational level is poorly understood. Here we analysed leaf- and tissue-specific translatomes using a set of transgenic Arabidopsis thaliana lines expressing a FLAG-tagged ribosomal protein to immunopurify polysome-bound mRNAs before and after oxidative stress. We determined transcript levels of 171 ROS-responsive genes upon paraquat treatment, which causes formation of superoxide radicals, at the whole-organ level. Furthermore, the translation of mRNAs was determined for five cell types: mesophyll, bundle sheath, phloem companion, epidermal and guard cells. Mesophyll and bundle sheath cells showed the strongest response to paraquat treatment. Interestingly, several ROS-responsive transcription factors displayed cell type-specific translation patterns, while others were translated in all cell types. In part, cell type-specific translation could be explained by the length of the 5-untranslated region (5-UTR) and the presence of upstream open reading frames (uORFs). Our analysis reveals insights into the translational regulation of ROS-responsive genes, which is important to understanding cell-specific responses and functions during oxidative stress. The study illustrates the response of different Arabidopsis thaliana leaf cells and tissues to oxidative stress at the translational level, an aspect of reactive oxygen species (ROS) biology that has been little studied in the past. Our data reveal insights into how translational regulation of ROS-responsive genes is fine-tuned at the cellular level, a phenomenon contributing to the integrated physiological response of leaves to stresses involving changes in ROS levels. KW - Arabidopsis KW - gene regulation KW - oxidative stress KW - tissue-specific KW - translation Y1 - 2015 U6 - https://doi.org/10.1111/pce.12355 SN - 0140-7791 SN - 1365-3040 VL - 38 IS - 2 SP - 349 EP - 363 PB - Wiley-Blackwell CY - Hoboken ER -