TY - JOUR A1 - Alseekh, Saleh A1 - Tohge, Takayuki A1 - Wendenberg, Regina A1 - Scossa, Federico A1 - Omranian, Nooshin A1 - Li, Jie A1 - Kleessen, Sabrina A1 - Giavalisco, Patrick A1 - Pleban, Tzili A1 - Müller-Röber, Bernd A1 - Zamir, Dani A1 - Nikoloski, Zoran A1 - Fernie, Alisdair R. T1 - Identification and Mode of Inheritance of Quantitative Trait Loci for Secondary Metabolite Abundance in Tomato JF - The plant cell N2 - A large-scale metabolic quantitative trait loci (mQTL) analysis was performed on the well-characterized Solanum pennellii introgression lines to investigate the genomic regions associated with secondary metabolism in tomato fruit pericarp. In total, 679 mQTLs were detected across the 76 introgression lines. Heritability analyses revealed that mQTLs of secondary metabolism were less affected by environment than mQTLs of primary metabolism. Network analysis allowed us to assess the interconnectivity of primary and secondary metabolism as well as to compare and contrast their respective associations with morphological traits. Additionally, we applied a recently established real-time quantitative PCR platform to gain insight into transcriptional control mechanisms of a subset of the mQTLs, including those for hydroxycinnamates, acyl-sugar, naringenin chalcone, and a range of glycoalkaloids. Intriguingly, many of these compounds displayed a dominant-negative mode of inheritance, which is contrary to the conventional wisdom that secondary metabolite contents decreased on domestication. We additionally performed an exemplary evaluation of two candidate genes for glycolalkaloid mQTLs via the use of virus-induced gene silencing. The combined data of this study were compared with previous results on primary metabolism obtained from the same material and to other studies of natural variance of secondary metabolism. Y1 - 2015 U6 - https://doi.org/10.1105/tpc.114.132266 SN - 1040-4651 SN - 1532-298X VL - 27 IS - 3 SP - 485 EP - 512 PB - American Society of Plant Physiologists CY - Rockville ER - TY - JOUR A1 - Arvidsson, Samuel Janne A1 - Perez-Rodriguez, Paulino A1 - Müller-Röber, Bernd T1 - A growth phenotyping pipeline for Arabidopsis thaliana integrating image analysis and rosette area modeling for robust quantification of genotype effects JF - New phytologist : international journal of plant science N2 - To gain a deeper understanding of the mechanisms behind biomass accumulation, it is important to study plant growth behavior. Manually phenotyping large sets of plants requires important human resources and expertise and is typically not feasible for detection of weak growth phenotypes. Here, we established an automated growth phenotyping pipeline for Arabidopsis thaliana to aid researchers in comparing growth behaviors of different genotypes. The analysis pipeline includes automated image analysis of two-dimensional digital plant images and evaluation of manually annotated information of growth stages. It employs linear mixed-effects models to quantify genotype effects on total rosette area and relative leaf growth rate (RLGR) and ANOVAs to quantify effects on developmental times. Using the system, a single researcher can phenotype up to 7000 plants d(-1). Technical variance is very low (typically < 2%). We show quantitative results for the growth-impaired starch-excessmutant sex4-3 and the growth-enhancedmutant grf9. We show that recordings of environmental and developmental variables reduce noise levels in the phenotyping datasets significantly and that careful examination of predictor variables (such as d after sowing or germination) is crucial to avoid exaggerations of recorded phenotypes and thus biased conclusions. KW - development KW - growth KW - leaf area KW - modeling KW - phenotyping Y1 - 2011 U6 - https://doi.org/10.1111/j.1469-8137.2011.03756.x SN - 0028-646X VL - 191 IS - 3 SP - 895 EP - 907 PB - Wiley-Blackwell CY - Malden ER - TY - JOUR A1 - Balazadeh, Salma A1 - Jaspert, Nils A1 - Arif, Muhammad A1 - Müller-Röber, Bernd A1 - Maurino, Veronica G. T1 - Expression of ROS-responsive genes and transcription factors after metabolic formation of H2O2 in chloroplasts JF - Frontiers in plant science N2 - Glycolate oxidase (GO) catalyses the oxidation of glycolate to glyoxylate, thereby consuming O-2 and producing H2O2. In this work, Arabidopsis thaliana plants expressing GO in the chloroplasts (GO plants) were used to assess the expressional behavior of reactive oxygen species (ROS)-responsive genes and transcription factors (TFs) after metabolic induction of H2O2 formation in chloroplasts. In this organelle, GO uses the glycolate derived from the oxygenase activity of RubisCO. Here, to identify genes responding to an abrupt production of H2O2 in chloroplasts we used quantitative real-time PCR (qRT-PCR) to test the expression of 187 ROS-responsive genes and 1880 TFs after transferring GO and wild-type (WT) plants grown at high CO2 levels to ambient CO2 concentration. Our data revealed coordinated expression changes of genes of specific functional networks 0.5 h after metabolic induction of H2O2 production in GO plants, including the induction of indole glucosinolate and camalexin biosynthesis genes. Comparative analysis using available microarray data suggests that signals for the induction of these genes through H2O2 may originate in the chloroplast. The TF profiling indicated an up-regulation in GO plants of a group of genes involved in the regulation of proanthocyanidin and anthocyanin biosynthesis. Moreover, the upregulation of expression of IF and IF interacting proteins affecting development (e.g., cell division, stem branching, flowering time, flower development) would impact growth and reproductive capacity, resulting in altered development under conditions that promote the formation of H2O2. KW - glycolate oxidase KW - H2O2 KW - ROS-responsive genes KW - transcription factors Y1 - 2012 U6 - https://doi.org/10.3389/fpls.2012.00234 SN - 1664-462X VL - 3 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Balazadeh, Salma A1 - Kwasniewski, Miroslaw A1 - Caldana, Camila A1 - Mehrnia, Mohammad A1 - Zanor, Maria Ines A1 - Xue, Gang-Ping A1 - Müller-Röber, Bernd T1 - ORS1, an H2O2-Responsive NAC Transcription Factor, Controls Senescence in Arabidopsis thaliana JF - Molecular plant N2 - We report here that ORS1, a previously uncharacterized member of the NAC transcription factor family, controls leaf senescence in Arabidopsis thaliana. Overexpression of ORS1 accelerates senescence in transgenic plants, whereas its inhibition delays it. Genes acting downstream of ORS1 were identified by global expression analysis using transgenic plants producing dexamethasone-inducible ORS1-GR fusion protein. Of the 42 up-regulated genes, 30 (similar to 70%) were previously shown to be up-regulated during age-dependent senescence. We also observed that 32 (similar to 76%) of the ORS1-dependent genes were induced by long-term (4 d), but not short-term (6 h) salinity stress (150 mM NaCl). Furthermore, expression of 16 and 24 genes, respectively, was induced after 1 and 5 h of treatment with hydrogen peroxide (H2O2), a reactive oxygen species known to accumulate during salinity stress. ORS1 itself was found to be rapidly and strongly induced by H2O2 treatment in both leaves and roots. Using in vitro binding site selection, we determined the preferred binding motif of ORS1 and found it to be present in half of the ORS1-dependent genes. ORS1 is a paralog of ORE1/ANAC092/AtNAC2, a previously reported regulator of leaf senescence. Phylogenetic footprinting revealed evolutionary conservation of the ORS1 and ORE1 promoter sequences in different Brassicaceae species, indicating strong positive selection acting on both genes. We conclude that ORS1, similarly to ORE1, triggers expression of senescence-associated genes through a regulatory network that may involve cross-talk with salt- and H2O2-dependent signaling pathways. KW - NAC transcription factor KW - leaf senescence KW - gene expression KW - gene regulatory network KW - hydrogen peroxide Y1 - 2011 U6 - https://doi.org/10.1093/mp/ssq080 SN - 1674-2052 VL - 4 IS - 2 SP - 346 EP - 360 PB - Oxford Univ. Press CY - Oxford ER - TY - GEN A1 - Balazadeh, Salma A1 - Müller-Röber, Bernd T1 - A balance to death T2 - Nature plants N2 - Leaf senescence plays a crucial role in nutrient recovery in late-stage plant development and requires vast transcriptional reprogramming by transcription factors such as ORESARA1 (ORE1). A proteolytic mechanism is now found to control ORE1 degradation, and thus senescence, during nitrogen starvation. Y1 - 2018 U6 - https://doi.org/10.1038/s41477-018-0279-6 SN - 2055-026X SN - 2055-0278 VL - 4 IS - 11 SP - 863 EP - 864 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Balazadeh, Salma A1 - Schildhauer, Joerg A1 - Araujo, Wagner L. A1 - Munne-Bosch, Sergi A1 - Fernie, Alisdair R. A1 - Proost, Sebastian A1 - Humbeck, Klaus A1 - Müller-Röber, Bernd T1 - Reversal of senescence by N resupply to N-starved Arabidopsis thaliana: transcriptomic and metabolomic consequences JF - Journal of experimental botany N2 - Leaf senescence is a developmentally controlled process, which is additionally modulated by a number of adverse environmental conditions. Nitrogen shortage is a well-known trigger of precocious senescence in many plant species including crops, generally limiting biomass and seed yield. However, leaf senescence induced by nitrogen starvation may be reversed when nitrogen is resupplied at the onset of senescence. Here, the transcriptomic, hormonal, and global metabolic rearrangements occurring during nitrogen resupply-induced reversal of senescence in Arabidopsis thaliana were analysed. The changes induced by senescence were essentially in keeping with those previously described; however, these could, by and large, be reversed. The data thus indicate that plants undergoing senescence retain the capacity to sense and respond to the availability of nitrogen nutrition. The combined data are discussed in the context of the reversibility of the senescence programme and the evolutionary benefit afforded thereby. Future prospects for understanding and manipulating this process in both Arabidopsis and crop plants are postulated. KW - Arabidopsis KW - gene expression KW - metabolomics KW - nitrogen limitation KW - senescence KW - transcriptome Y1 - 2014 U6 - https://doi.org/10.1093/jxb/eru119 SN - 0022-0957 SN - 1460-2431 VL - 65 IS - 14 SP - 3975 EP - 3992 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Balazadeh, Salma A1 - Siddiqui, Hamad A1 - Allu, Annapurna Devi A1 - Matallana-Ramirez, Lilian Paola A1 - Caldana, Camila A1 - Mehrnia, Mohammad A1 - Zanor, Maria-Inés A1 - Koehler, Barbara A1 - Müller-Röber, Bernd T1 - A gene regulatory network controlled by the NAC transcription factor ANAC092/AtNAC2/ORE1 during salt-promoted senescence N2 - P>The onset and progression of senescence are under genetic and environmental control. The Arabidopsis thaliana NAC transcription factor ANAC092 (also called AtNAC2 and ORE1) has recently been shown to control age-dependent senescence, but its mode of action has not been analysed yet. To explore the regulatory network administered by ANAC092 we performed microarray-based expression profiling using estradiol-inducible ANAC092 overexpression lines. Approximately 46% of the 170 genes up-regulated upon ANAC092 induction are known senescence-associated genes, suggesting that the NAC factor exerts its role in senescence through a regulatory network that includes many of the genes previously reported to be senescence regulated. We selected 39 candidate genes and confirmed their time-dependent response to enhanced ANAC092 expression by quantitative RT-PCR. We also found that the majority of them (24 genes) are up-regulated by salt stress, a major promoter of plant senescence, in a manner similar to that of ANAC092, which itself is salt responsive. Furthermore, 24 genes like ANAC092 turned out to be stage-dependently expressed during seed growth with low expression at early and elevated expression at late stages of seed development. Disruption of ANAC092 increased the rate of seed germination under saline conditions, whereas the opposite occurred in respective overexpression plants. We also detected a delay of salinity-induced chlorophyll loss in detached anac092-1 mutant leaves. Promoter-reporter (GUS) studies revealed transcriptional control of ANAC092 expression during leaf and flower ageing and in response to salt stress. We conclude that ANAC092 exerts its functions during senescence and seed germination through partly overlapping target gene sets. Y1 - 2010 UR - http://www3.interscience.wiley.com/cgi-bin/issn?DESCRIPTOR=PRINTISSN&VALUE=0960-7412 U6 - https://doi.org/10.1111/j.1365-313X.2010.04151.x SN - 0960-7412 ER - TY - JOUR A1 - Banks, Jo Ann A1 - Nishiyama, Tomoaki A1 - Hasebe, Mitsuyasu A1 - Bowman, John L. A1 - Gribskov, Michael A1 - dePamphilis, Claude A1 - Albert, Victor A. A1 - Aono, Naoki A1 - Aoyama, Tsuyoshi A1 - Ambrose, Barbara A. A1 - Ashton, Neil W. A1 - Axtell, Michael J. A1 - Barker, Elizabeth A1 - Barker, Michael S. A1 - Bennetzen, Jeffrey L. A1 - Bonawitz, Nicholas D. A1 - Chapple, Clint A1 - Cheng, Chaoyang A1 - Correa, Luiz Gustavo Guedes A1 - Dacre, Michael A1 - DeBarry, Jeremy A1 - Dreyer, Ingo A1 - Elias, Marek A1 - Engstrom, Eric M. A1 - Estelle, Mark A1 - Feng, Liang A1 - Finet, Cedric A1 - Floyd, Sandra K. A1 - Frommer, Wolf B. A1 - Fujita, Tomomichi A1 - Gramzow, Lydia A1 - Gutensohn, Michael A1 - Harholt, Jesper A1 - Hattori, Mitsuru A1 - Heyl, Alexander A1 - Hirai, Tadayoshi A1 - Hiwatashi, Yuji A1 - Ishikawa, Masaki A1 - Iwata, Mineko A1 - Karol, Kenneth G. A1 - Koehler, Barbara A1 - Kolukisaoglu, Uener A1 - Kubo, Minoru A1 - Kurata, Tetsuya A1 - Lalonde, Sylvie A1 - Li, Kejie A1 - Li, Ying A1 - Litt, Amy A1 - Lyons, Eric A1 - Manning, Gerard A1 - Maruyama, Takeshi A1 - Michael, Todd P. A1 - Mikami, Koji A1 - Miyazaki, Saori A1 - Morinaga, Shin-ichi A1 - Murata, Takashi A1 - Müller-Röber, Bernd A1 - Nelson, David R. A1 - Obara, Mari A1 - Oguri, Yasuko A1 - Olmstead, Richard G. A1 - Onodera, Naoko A1 - Petersen, Bent Larsen A1 - Pils, Birgit A1 - Prigge, Michael A1 - Rensing, Stefan A. A1 - Mauricio Riano-Pachon, Diego A1 - Roberts, Alison W. A1 - Sato, Yoshikatsu A1 - Scheller, Henrik Vibe A1 - Schulz, Burkhard A1 - Schulz, Christian A1 - Shakirov, Eugene V. A1 - Shibagaki, Nakako A1 - Shinohara, Naoki A1 - Shippen, Dorothy E. A1 - Sorensen, Iben A1 - Sotooka, Ryo A1 - Sugimoto, Nagisa A1 - Sugita, Mamoru A1 - Sumikawa, Naomi A1 - Tanurdzic, Milos A1 - Theissen, Guenter A1 - Ulvskov, Peter A1 - Wakazuki, Sachiko A1 - Weng, Jing-Ke A1 - Willats, William W. G. T. A1 - Wipf, Daniel A1 - Wolf, Paul G. A1 - Yang, Lixing A1 - Zimmer, Andreas D. A1 - Zhu, Qihui A1 - Mitros, Therese A1 - Hellsten, Uffe A1 - Loque, Dominique A1 - Otillar, Robert A1 - Salamov, Asaf A1 - Schmutz, Jeremy A1 - Shapiro, Harris A1 - Lindquist, Erika A1 - Lucas, Susan A1 - Rokhsar, Daniel A1 - Grigoriev, Igor V. T1 - The selaginella genome identifies genetic changes associated with the evolution of vascular plants JF - Science N2 - Vascular plants appeared similar to 410 million years ago, then diverged into several lineages of which only two survive: the euphyllophytes (ferns and seed plants) and the lycophytes. We report here the genome sequence of the lycophyte Selaginella moellendorffii (Selaginella), the first nonseed vascular plant genome reported. By comparing gene content in evolutionarily diverse taxa, we found that the transition from a gametophyte- to a sporophyte-dominated life cycle required far fewer new genes than the transition from a nonseed vascular to a flowering plant, whereas secondary metabolic genes expanded extensively and in parallel in the lycophyte and angiosperm lineages. Selaginella differs in posttranscriptional gene regulation, including small RNA regulation of repetitive elements, an absence of the trans-acting small interfering RNA pathway, and extensive RNA editing of organellar genes. Y1 - 2011 U6 - https://doi.org/10.1126/science.1203810 SN - 0036-8075 VL - 332 IS - 6032 SP - 960 EP - 963 PB - American Assoc. for the Advancement of Science CY - Washington ER - TY - JOUR A1 - Becker, Dirk A1 - Geiger, D. A1 - Dunkel, M. A1 - Roller, A. A1 - Bertl, Adam A1 - Latz, A. A1 - Carpaneto, Armando A1 - Dietrich, Peter A1 - Roelfsema, M. R. G. A1 - Voelker, C. A1 - Schmidt, D. A1 - Müller-Röber, Bernd A1 - Czempinski, Katrin A1 - Hedrich, R. T1 - AtTPK4, an Arabidopsis tandem-pore K+ channel, poised to control the pollen membrane voltage in a pH- and Ca2+- dependent manner N2 - The Arabidopsis tandem-pore K+ (TPK) channels displaying four transmembrane domains and two pore regions share structural homologies with their animal counterparts of the KCNK family. In contrast to the Shaker-like Arabidopsis channels (six transmembrane domains/one pore region), the functional properties and the biological role of plant TPK channels have not been elucidated yet. Here, we show that AtTPK4 (KCO4) localizes to the plasma membrane and is predominantly expressed in pollen. AtTPK4 (KCO4) resembles the electrical properties of a voltage-independent K+ channel after expression in Xenopus oocytes and yeast. Hyperpolarizing as well as depolarizing membrane voltages elicited instantaneous K+ currents, which were blocked by extracellular calcium and cytoplasmic protons. Functional complementation assays using a K+ transport-deficient yeast confirmed the biophysical and pharmacological properties of the AtTPK4 channel. The features of AtTPK4 point toward a role in potassium homeostasis and membrane voltage control of the growing pollen tube. Thus, AtTPK4 represents a member of plant tandem-pore-K+ channels, resembling the characteristics of its animal counterparts as well as plant-specific features with respect to modulation of channel activity by acidosis and calcium Y1 - 2004 SN - 0027-8424 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 - TY - JOUR A1 - Brotman, Yariv A1 - Landau, Udi A1 - Pnini, Smadar A1 - Lisec, Jan A1 - Balazadeh, Salma A1 - Müller-Röber, Bernd A1 - Zilberstein, Aviah A1 - Willmitzer, Lothar A1 - Chet, Ilan A1 - Viterbo, Ada T1 - The LysM Receptor-Like Kinase LysM RLK1 is required to activate defense and abiotic-stress responses induced by overexpression of fungal chitinases in arabidopsis plants JF - Molecular plant N2 - Application of crab shell chitin or pentamer chitin oligosaccharide to Arabidopsis seedlings increased tolerance to salinity in wild-type but not in knockout mutants of the LysM Receptor-Like Kinase1 (CERK1/LysM RLK1) gene, known to play a critical role in signaling defense responses induced by exogenous chitin. Arabidopsis plants overexpressing the endochitinase chit36 and hexoaminidase excy1 genes from the fungus Trichoderma asperelleoides T203 showed increased tolerance to salinity, heavy-metal stresses, and Botrytis cinerea infection. Resistant lines, overexpressing fungal chitinases at different levels, were outcrossed to lysm rlk1 mutants. Independent homozygous hybrids lost resistance to biotic and abiotic stresses, despite enhanced chitinase activity. Expression analysis of 270 stress-related genes, including those induced by reactive oxygen species (ROS) and chitin, revealed constant up-regulation (at least twofold) of 10 genes in the chitinase-overexpressing line and an additional 76 salt-induced genes whose expression was not elevated in the lysm rlk1 knockout mutant or the hybrids harboring the mutation. These findings elucidate that chitin-induced signaling mediated by LysM RLK1 receptor is not limited to biotic stress response but also encompasses abiotic-stress signaling and can be conveyed by ectopic expression of chitinases in plants. KW - abiotic stress KW - chitin-induced signaling KW - chitinases KW - LysM receptor kinase KW - Trichoderma Y1 - 2012 U6 - https://doi.org/10.1093/mp/sss021 SN - 1674-2052 VL - 5 IS - 5 SP - 1113 EP - 1124 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Czarnocka, Weronika A1 - Van Der Kelen, Katrien A1 - Willems, Patrick A1 - Szechynska-Hebda, Magdalena A1 - Shahnejat-Bushehri, Sara A1 - Balazadeh, Salma A1 - Rusaczonek, Anna A1 - Müller-Röber, Bernd A1 - Van Breusegem, Frank A1 - Karpinski, Stanislaw T1 - The dual role of LESION SIMULATING DISEASE 1 as a condition-dependent scaffold protein and transcription regulator JF - Plant, cell & environment : cell physiology, whole-plant physiology, community physiology N2 - Since its discovery over two decades ago as an important cell death regulator in Arabidopsis thaliana, the role of LESION SIMULATING DISEASE 1 (LSD1) has been studied intensively within both biotic and abiotic stress responses as well as with respect to plant fitness regulation. However, its molecular mode of action remains enigmatic. Here, we demonstrate that nucleo-cytoplasmic LSD1 interacts with a broad range of other proteins that are engaged in various molecular pathways such as ubiquitination, methylation, cell cycle control, gametogenesis, embryo development and cell wall formation. The interaction of LSD1 with these partners is dependent on redox status, as oxidative stress significantly changes the quantity and types of LSD1-formed complexes. Furthermore, we show that LSD1 regulates the number and size of leaf mesophyll cells and affects plant vegetative growth. Importantly, we also reveal that in addition to its function as a scaffold protein, LSD1 acts as a transcriptional regulator. Taken together, our results demonstrate that LSD1 plays a dual role within the cell by acting as a condition-dependent scaffold protein and as a transcription regulator. KW - Arabidopsis KW - thaliana KW - dry weight KW - LSD1 KW - oxidative stress KW - protein interaction KW - transcription regulation Y1 - 2017 U6 - https://doi.org/10.1111/pce.12994 SN - 0140-7791 SN - 1365-3040 VL - 40 SP - 2644 EP - 2662 PB - Wiley CY - Hoboken ER - TY - GEN A1 - Das Gupta, Mainak A1 - Roesch, Florian A1 - Hochrein, Lena A1 - Machens, Fabian A1 - Müller-Röber, Bernd T1 - Facilitating Genome Engineering Through RNP-mediated Precise Gene Targeting T2 - In Vitro Cellular & Developmental Biology - Plant Y1 - 2019 SN - 1054-5476 SN - 1475-2689 VL - 55 IS - 4 SP - 481 EP - 481 PB - Springer CY - New York ER - TY - JOUR A1 - Dong, Yanni A1 - Gupta, Saurabh A1 - Sievers, Rixta A1 - Wargent, Jason J. A1 - Wheeler, David A1 - Putterill, Joanna A1 - Macknight, Richard A1 - Gechev, Tsanko S. A1 - Müller-Röber, Bernd A1 - Dijkwel, Paul P. T1 - Genome draft of the Arabidopsis relative Pachycladon cheesemanii reveals environment JF - BMC genomics N2 - BackgroundPachycladon cheesemanii is a close relative of Arabidopsis thaliana and is an allotetraploid perennial herb which is widespread in the South Island of New Zealand. It grows at altitudes of up to 1000m where it is subject to relatively high levels of ultraviolet (UV)-B radiation. To gain first insights into how Pachycladon copes with UV-B stress, we sequenced its genome and compared the UV-B tolerance of two Pachycladon accessions with those of two A. thaliana accessions from different altitudes.ResultsA high-quality draft genome of P. cheesemanii was assembled with a high percentage of conserved single-copy plant orthologs. Synteny analysis with genomes from other species of the Brassicaceae family found a close phylogenetic relationship of P. cheesemanii with Boechera stricta from Brassicaceae lineage I. While UV-B radiation caused a greater growth reduction in the A. thaliana accessions than in the P. cheesemanii accessions, growth was not reduced in one P. cheesemanii accession. The homologues of A. thaliana UV-B radiation response genes were duplicated in P. cheesemanii, and an expression analysis of those genes indicated that the tolerance mechanism in P. cheesemanii appears to differ from that in A. thaliana.ConclusionAlthough the P. cheesemanii genome shows close similarity with that of A. thaliana, it appears to have evolved novel strategies allowing the plant to tolerate relatively high UV-B radiation. KW - Abiotic stress KW - Arabidopsis KW - Genome assembly KW - Pachycladon KW - UV-B tolerance Y1 - 2019 U6 - https://doi.org/10.1186/s12864-019-6084-4 SN - 1471-2164 VL - 20 IS - 1 PB - BMC CY - London ER - TY - JOUR A1 - Dortay, Hakan A1 - Akula, Usha Madhuri A1 - Westphal, Christin A1 - Sittig, Marie A1 - Müller-Röber, Bernd T1 - High-throughput protein expression using a combination of ligation-independent cloning (LIC) and infrared fluorescent protein (IFP) detection JF - PLoS one N2 - Protein expression in heterologous hosts for functional studies is a cumbersome effort. Here, we report a superior platform for parallel protein expression in vivo and in vitro. The platform combines highly efficient ligation-independent cloning (LIC) with instantaneous detection of expressed proteins through N- or C-terminal fusions to infrared fluorescent protein (IFP). For each open reading frame, only two PCR fragments are generated (with three PCR primers) and inserted by LIC into ten expression vectors suitable for protein expression in microbial hosts, including Escherichia coli, Kluyveromyces lactis, Pichia pastoris, the protozoon Leishmania tarentolae, and an in vitro transcription/translation system. Accumulation of IFP-fusion proteins is detected by infrared imaging of living cells or crude protein extracts directly after SDS-PAGE without additional processing. We successfully employed the LIC-IFP platform for in vivo and in vitro expression of ten plant and fungal proteins, including transcription factors and enzymes. Using the IFP reporter, we additionally established facile methods for the visualisation of protein-protein interactions and the detection of DNA-transcription factor interactions in microtiter and gel-free format. We conclude that IFP represents an excellent reporter for high-throughput protein expression and analysis, which can be easily extended to numerous other expression hosts using the setup reported here. Y1 - 2011 U6 - https://doi.org/10.1371/journal.pone.0018900 SN - 1932-6203 VL - 6 IS - 4 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Dortay, Hakan A1 - Müller-Röber, Bernd T1 - A highly efficient pipeline for protein expression in Leishmania tarentolae using infrared fluorescence protein as marker N2 - Background: Leishmania tarentolae, a unicellular eukaryotic protozoan, has been established as a novel host for recombinant protein production in recent years. Current protocols for protein expression in Leishmania are, however, time consuming and require extensive lab work in order to identify well-expressing cell lines. Here we established an alternative protein expression work-flow that employs recently engineered infrared fluorescence protein (IFP) as a suitable and easy-to-handle reporter protein for recombinant protein expression in Leishmania. As model proteins we tested three proteins from the plant Arabidopsis thaliana, including a NAC and a type-B ARR transcription factor. Results: IFP and IFP fusion proteins were expressed in Leishmania and rapidly detected in cells by deconvolution microscopy and in culture by infrared imaging of 96-well microtiter plates using small cell culture volumes (2 mu L Y1 - 2010 UR - http://www.microbialcellfactories.com/home/ U6 - https://doi.org/10.1186/1475-2859-9-29 SN - 1475-2859 ER - TY - JOUR A1 - Dortay, Hakan A1 - Schmöckel, Sandra M. A1 - Fettke, Jörg A1 - Müller-Röber, Bernd T1 - Expression of human c-reactive protein in different systems and its purification from Leishmania tarentolae JF - Protein expression and purification N2 - With its homo-pentameric structure and calcium-dependent specificity for phosphocholine (PCh), human c-reactive protein (CRP) is produced by the liver and secreted in elevated quantities in response to inflammation. CRP is widely accepted as a cardiac marker, e.g. in point-of-care diagnostics, however, its heterologous expression has proven difficult. Here, we demonstrate the expression of CRP in different Escherichia coli strains as well as by in vitro transcription/translation. Although expression in these systems was straightforward, most of the protein that accumulated was insoluble. We therefore expanded our study to include the expression of CRP in two eukaryotic hosts, namely the yeast Kluyveromyces lactis and the protozoon Leishmania tarentolae. Both expression systems are optimized for secretion of recombinant proteins and here allowed successful expression of soluble CRP. We also demonstrate the purification of recombinant CRP from Leishmania growth medium; the purification of protein expressed from K. lactis was not successful. Functional and intact CRP pentamer is known to interact with PCh in Ca(2+)-dependent manner. In this report we verify the binding specificity of recombinant CRP from L tarentolae (2 mu g/mL culture medium) for PCh. KW - C-reactive protein KW - Protein expression KW - Leishmania KW - In vitro expression KW - Protein purification Y1 - 2011 U6 - https://doi.org/10.1016/j.pep.2011.03.010 SN - 1046-5928 VL - 78 IS - 1 SP - 55 EP - 60 PB - Elsevier CY - San Diego ER - TY - JOUR A1 - Dreyer, Ingo A1 - Poree, Fabien A1 - Schneider, A. A1 - Mittelstadt, J. A1 - Bertl, Adam A1 - Sentenac, H. A1 - Thibaud, Jean-Baptiste A1 - Müller-Röber, Bernd T1 - Assembly of plant Shaker-like K-out channels requires two distinct sites of the channel alpha-subunit N2 - SKOR and GORK are outward-rectifying plant potassium channels from Arabidopsis thaliana. They belong to the Shaker superfamily of voltage-dependent K+ channels. Channels of this class are composed of four alpha-subunits and subunit assembly is a prerequisite for channel function. In this study the assembly mechanism of SKOR was investigated using the yeast two-hybrid system and functional assays in Xenopus oocytes and in yeast. We demonstrate that SKOR and GORK physically interact and assemble into heteromeric K-out channels. Deletion mutants and chimeric proteins generated from SKOR and the K-in channel alpha-subunit KAT1 revealed that the cytoplasmic C-terminus of SKOR determines channel assembly. Two domains thatchannel a-subunit KAT1 revealed that the cytoplasmic C-terminus of SKOR determines channel assembly. Two domains that are crucial for channel assembly were identified: i), a proximal interacting region comprising a putative cyclic nucleotide-binding domain together with 33 amino acids just upstream of this domain, and ii), a distal interacting region showing some resemblance to the K-T domain of KAT1. Both regions contributed differently to channel assembly. Whereas the proximal interacting region was found to be active on its own, the distal interacting region required an intact proximal interacting region to be active. K-out alpha-subunits did not assemble with K-in alpha-subunits because of the absence of interaction between their assembly sites Y1 - 2004 SN - 0006-3495 ER - TY - JOUR A1 - Durgud, Meriem A1 - Gupta, Saurabh A1 - Ivanov, Ivan A1 - Omidbakhshfard, Mohammad Amin A1 - Benina, Maria A1 - Alseekh, Saleh A1 - Staykov, Nikola A1 - Hauenstein, Mareike A1 - Dijkwel, Paul P. A1 - Hortensteiner, Stefan A1 - Toneva, Valentina A1 - Brotman, Yariv A1 - Fernie, Alisdair R. A1 - Müller-Röber, Bernd A1 - Gechev, Tsanko S. T1 - Molecular Mechanisms Preventing Senescence in Response to Prolonged Darkness in a Desiccation-Tolerant Plant JF - Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants N2 - The desiccation-tolerant plant Haberlea rhodopensis can withstand months of darkness without any visible senescence. Here, we investigated the molecular mechanisms of this adaptation to prolonged (30 d) darkness and subsequent return to light. H. rhodopensis plants remained green and viable throughout the dark treatment. Transcriptomic analysis revealed that darkness regulated several transcription factor (TF) genes. Stress-and autophagy-related TFs such as ERF8, HSFA2b, RD26, TGA1, and WRKY33 were up-regulated, while chloroplast-and flowering-related TFs such as ATH1, COL2, COL4, RL1, and PTAC7 were repressed. PHYTOCHROME INTERACTING FACTOR4, a negative regulator of photomorphogenesis and promoter of senescence, also was down-regulated. In response to darkness, most of the photosynthesis-and photorespiratory-related genes were strongly down-regulated, while genes related to autophagy were up-regulated. This occurred concomitant with the induction of SUCROSE NON-FERMENTING1-RELATED PROTEIN KINASES (SnRK1) signaling pathway genes, which regulate responses to stress-induced starvation and autophagy. Most of the genes associated with chlorophyll catabolism, which are induced by darkness in dark-senescing species, were either unregulated (PHEOPHORBIDE A OXYGENASE, PAO; RED CHLOROPHYLL CATABOLITE REDUCTASE, RCCR) or repressed (STAY GREEN-LIKE, PHEOPHYTINASE, and NON-YELLOW COLORING1). Metabolite profiling revealed increases in the levels of many amino acids in darkness, suggesting increased protein degradation. In darkness, levels of the chloroplastic lipids digalactosyldiacylglycerol, monogalactosyldiacylglycerol, phosphatidylglycerol, and sulfoquinovosyldiacylglycerol decreased, while those of storage triacylglycerols increased, suggesting degradation of chloroplast membrane lipids and their conversion to triacylglycerols for use as energy and carbon sources. Collectively, these data show a coordinated response to darkness, including repression of photosynthetic, photorespiratory, flowering, and chlorophyll catabolic genes, induction of autophagy and SnRK1 pathways, and metabolic reconfigurations that enable survival under prolonged darkness. Y1 - 2018 U6 - https://doi.org/10.1104/pp.18.00055 SN - 0032-0889 SN - 1532-2548 VL - 177 IS - 3 SP - 1319 EP - 1338 PB - American Society of Plant Physiologists CY - Rockville ER - TY - JOUR A1 - Engqvist, Martin K. M. A1 - Schmitz, Jessica A1 - Gertzmann, Anke A1 - Florian, Alexandra A1 - Jaspert, Nils A1 - Arif, Muhammad A1 - Balazadeh, Salma A1 - Müller-Röber, Bernd A1 - Fernie, Alisdair R. A1 - Maurino, Veronica G. T1 - GLYCOLATE OXIDASE3, a Glycolate Oxidase Homolog of Yeast L-Lactate Cytochrome c Oxidoreductase, Supports L-Lactate Oxidation in Roots of Arabidopsis JF - Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants N2 - In roots of Arabidopsis (Arabidopsis thaliana), L-lactate is generated by the reduction of pyruvate via L-lactate dehydrogenase, but this enzyme does not efficiently catalyze the reverse reaction. Here, we identify the Arabidopsis glycolate oxidase (GOX) paralogs GOX1, GOX2, and GOX3 as putative L-lactate-metabolizing enzymes based on their homology to CYB2, the L-lactate cytochrome c oxidoreductase from the yeast Saccharomyces cerevisiae. We found that GOX3 uses L-lactate with a similar efficiency to glycolate; in contrast, the photorespiratory isoforms GOX1 and GOX2, which share similar enzymatic properties, use glycolate with much higher efficiencies than L-lactate. The key factor making GOX3 more efficient with L-lactate than GOX1 and GOX2 is a 5- to 10-fold lower Km for the substrate. Consequently, only GOX3 can efficiently metabolize L-lactate at low intracellular concentrations. Isotope tracer experiments as well as substrate toxicity tests using GOX3 loss-of-function and overexpressor plants indicate that L-lactate is metabolized in vivo by GOX3. Moreover, GOX3 rescues the lethal growth phenotype of a yeast strain lacking CYB2, which cannot grow on L-lactate as a sole carbon source. GOX3 is predominantly present in roots and mature to aging leaves but is largely absent from young photosynthetic leaves, indicating that it plays a role predominantly in heterotrophic rather than autotrophic tissues, at least under standard growth conditions. In roots of plants grown under normoxic conditions, loss of function of GOX3 induces metabolic rearrangements that mirror wild-type responses under hypoxia. Thus, we identified GOX3 as the enzyme that metabolizes L-lactate to pyruvate in vivo and hypothesize that it may ensure the sustainment of low levels of L-lactate after its formation under normoxia. Y1 - 2015 U6 - https://doi.org/10.1104/pp.15.01003 SN - 0032-0889 SN - 1532-2548 VL - 169 IS - 2 SP - 1042 EP - 1061 PB - American Society of Plant Physiologists CY - Rockville ER - TY - JOUR A1 - Faisal, Muhammad B. A1 - Gechev, Tsanko S. A1 - Müller-Röber, Bernd A1 - Dijkwel, Paul P. T1 - Putative alternative translation start site-encoding nucleotides of CPR5 regulate growth and resistance JF - BMC plant biology N2 - Background The Arabidopsis CONSTITUTIVE EXPRESSER of PATHOGENESIS-RELATED GENES 5 (CPR5) has recently been shown to play a role in gating as part of the nuclear pore complex (NPC). Mutations in CPR5 cause multiple defects, including aberrant trichomes, reduced ploidy levels, reduced growth and enhanced resistance to bacterial and fungal pathogens. The pleiotropic nature of cpr5 mutations implicates that the CPR5 protein affects multiple pathways. However, little is known about the structural features that allow CPR5 to affect the different pathways. Results Our in silico studies suggest that in addition to three clusters of putative nuclear localization signals and four or five transmembrane domains, CPR5 contains two putative alternative translation start sites. To test the role of the methionine-encoding nucleotides implicated in those sites, metCPR5 cDNAs, in which the relevant nucleotides were changed to encode glutamine, were fused to the CPR5 native promoter and the constructs transformed to cpr5-2 plants to complement cpr5-compromised phenotypes. The control and metCPR5 constructs were able to complement all cpr5 phenotypes, although the extent of complementation depended on the specific complementing plant lines. Remarkably, plants transformed with metCPR5 constructs showed larger leaves and displayed reduced resistance when challenged to Pseudomonas syringae pv Pst DC3000, as compared to control plants. Thus, the methionine-encoding nucleotides regulate growth and resistance. We propose that structural features of the CPR5 N-terminus are implicated in selective gating of proteins involved in regulating the balance between growth and resistance. Conclusion Plants need to carefully balance the amount of resources used for growth and resistance. The Arabidopsis CPR5 protein regulates plant growth and immunity. Here we show that N-terminal features of CPR5 are involved in the regulation of the balance between growth and resistance. These findings may benefit efforts to improve plant yield, while maintaining optimal levels of disease resistance. KW - CPR5 KW - plant growth KW - disease resistance KW - cell death KW - arabidopsis thaliana KW - endoreduplication Y1 - 2020 U6 - https://doi.org/10.1186/s12870-020-02485-2 SN - 1471-2229 VL - 20 IS - 1 PB - BMC CY - London ER - TY - JOUR A1 - Feng, Xiao-Li A1 - Ni, Wei-Min A1 - Elge, Stephan A1 - Müller-Röber, Bernd A1 - Xu, Zhi-Hong A1 - Xue, Hong-Wei T1 - Auxin flow in anther filaments is critical for pollen grain development through regulating pollen mitosis N2 - It was well known that auxin is critical for anther/pollen grain development, however, the clear distribution and detailed effects of auxin during floral development are still unclear. We have shown here that, through analyzing GUS activities of Arabidopsis lines harboring auxin response elements DR5-GUS, auxin was mainly accumulated in the anther during flower stages 10-12. Further studies employing the indoleacetic acid-lysine synthetase (iaaL) coding gene from Pseudomonas syringae subsp. savastanoi under control of the promoter region of Arabidopsis phosphatidylinositol monophosphate 5-kinase 1 gene, which conducts the anther filament-specific expression, showed that block of auxin flow of filaments resulted in shortened filaments and significantly defective pollen grains. Similar phenotype was observed in tobacco plants transformed with the same construct, confirming the effects of auxin flow in filaments on anther development. Detailed studies further revealed that the meiosis process of pollen grain was normal while the mitosis at later stage was significantly defected, indicating the effects of auxin flow in filaments on pollen grain mitosis process. Analysis employing [C-14]IAA, as well as the observation on the expression of AtPIN1, coding for auxin efflux carrier, demonstrated the presence of polar auxin transport in anther filaments and pollen grains Y1 - 2006 UR - http://www.springerlink.com/content/100330 U6 - https://doi.org/10.1007/s11103-006-0005-z SN - 0167-4412 ER - TY - JOUR A1 - Fichtner, Franziska A1 - Barbier, Francois F. A1 - Annunziata, Maria Grazia A1 - Feil, Regina A1 - Olas, Justyna Jadwiga A1 - Müller-Röber, Bernd A1 - Stitt, Mark A1 - Beveridge, Christine A. A1 - Lunn, John Edward T1 - Regulation of shoot branching in arabidopsis by trehalose 6-phosphate JF - New phytologist : international journal of plant science N2 - Trehalose 6-phosphate (Tre6P) is a sucrose signalling metabolite that has been implicated in regulation of shoot branching, but its precise role is not understood. We expressed tagged forms of TREHALOSE-6-PHOSPHATE SYNTHASE1 (TPS1) to determine where Tre6P is synthesized in arabidopsis (Arabidopsis thaliana), and investigated the impact of localized changes in Tre6P levels, in axillary buds or vascular tissues, on shoot branching in wild-type and branching mutant backgrounds. TPS1 is expressed in axillary buds and the subtending vasculature, as well as in the leaf and stem vasculature. Expression of a heterologous Tre6P phosphatase (TPP) to lower Tre6P in axillary buds strongly delayed bud outgrowth in long days and inhibited branching in short days. TPP expression in the vasculature also delayed lateral bud outgrowth and decreased branching. Increased Tre6P in the vasculature enhanced branching and was accompanied by higher expression of FLOWERING LOCUS T (FT) and upregulation of sucrose transporters. Increased vascular Tre6P levels enhanced branching in branched1 but not in ft mutant backgrounds. These results provide direct genetic evidence of a local role for Tre6P in regulation of axillary bud outgrowth within the buds themselves, and also connect Tre6P with systemic regulation of shoot branching via FT. KW - Arabidopsis thaliana (arabidopsis) KW - axillary bud KW - branching KW - sucrose KW - sugar signalling KW - trehalose 6‐ phosphate (Tre6P) Y1 - 2020 U6 - https://doi.org/10.1111/nph.17006 SN - 0028-646X SN - 1469-8137 VL - 229 IS - 4 SP - 2135 EP - 2151 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Gajdanowicz, Pawel A1 - Garcia-Mata, Carlos A1 - Gonzalez, Wendy A1 - Morales-Navarro, Samuel Elïas A1 - Sharma, Tripti A1 - Gonzalez-Nilo, Fernando Danilo A1 - Gutowicz, Jan A1 - Müller-Röber, Bernd A1 - Blatt, Michael R. A1 - Dreyer, Ingo T1 - Distinct roles of the last transmembrane domain in controlling Arabidopsis K+ channel activity N2 - The family of voltage-gated potassium channels in plants presumably evolved from a common ancestor and includes both inward-rectifying (K-in) channels that allow plant cells to accumulate K+ and outward-rectifying (K-out) channels that mediate K+ efflux. Despite their close structural similarities, the activity of Kin channels is largely independent of K+ and depends only on the transmembrane voltage, whereas that of K-out channels responds to the membrane voltage and the prevailing extracellular K+ concentration. Gating of potassium channels is achieved by structural rearrangements within the last transmembrane domain (S6). Here we investigated the functional equivalence of the S6 helices of the Kin channel KAT1 and the K-out channel SKOR by domain-swapping and site-directed mutagenesis. Channel mutants and chimeras were analyzed after expression in Xenopus oocytes. We identified two discrete regions that influence gating differently in both channels, demonstrating a lack of functional complementarity between KAT1 and SKOR. Our findings are supported by molecular models of KAT1 and SKOR in the open and closed states. The role of the S6 segment in gating evolved differently during specialization of the two channel subclasses, posing an obstacle for the transfer of the K+-sensor from K-out to K-in channels. Y1 - 2009 UR - http://www3.interscience.wiley.com/cgi-bin/issn?DESCRIPTOR=PRINTISSN&VALUE=0028-646X U6 - https://doi.org/10.1111/j.1469-8137.2008.02749.x SN - 0028-646X ER - TY - JOUR A1 - Garapati, Prashanth A1 - Feil, Regina A1 - Lunn, John Edward A1 - Van Dijck, Patrick A1 - Balazadeh, Salma A1 - Müller-Röber, Bernd T1 - Transcription Factor Arabidopsis Activating Factor1 Integrates Carbon Starvation Responses with Trehalose Metabolism JF - Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants N2 - Plants respond to low carbon supply by massive reprogramming of the transcriptome and metabolome. We show here that the carbon starvation-induced NAC (for NO APICAL MERISTEM/ARABIDOPSIS TRANSCRIPTION ACTIVATION FACTOR/CUP-SHAPED COTYLEDON) transcription factor Arabidopsis (Arabidopsis thaliana) Transcription Activation Factor1 (ATAF1) plays an important role in this physiological process. We identified TREHALASE1, the only trehalase-encoding gene in Arabidopsis, as a direct downstream target of ATAF1. Overexpression of ATAF1 activates TREHALASE1 expression and leads to reduced trehalose-6-phosphate levels and a sugar starvation metabolome. In accordance with changes in expression of starch biosynthesis-and breakdown-related genes, starch levels are generally reduced in ATAF1 overexpressors but elevated in ataf1 knockout plants. At the global transcriptome level, genes affected by ATAF1 are broadly associated with energy and carbon starvation responses. Furthermore, transcriptional responses triggered by ATAF1 largely overlap with expression patterns observed in plants starved for carbon or energy supply. Collectively, our data highlight the existence of a positively acting feedforward loop between ATAF1 expression, which is induced by carbon starvation, and the depletion of cellular carbon/energy pools that is triggered by the transcriptional regulation of downstream gene regulatory networks by ATAF1. Y1 - 2015 U6 - https://doi.org/10.1104/pp.15.00917 SN - 0032-0889 SN - 1532-2548 VL - 169 IS - 1 SP - 379 EP - 390 PB - American Society of Plant Physiologists CY - Rockville 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 - Gechev, Tsanko S. A1 - Hille, Jacques A1 - Woerdenbag, Herman J. A1 - Benina, Maria A1 - Mehterov, Nikolay A1 - Toneva, Valentina A1 - Fernie, Alisdair R. A1 - Müller-Röber, Bernd T1 - Natural products from resurrection plants: Potential for medical applications JF - Biotechnology advances : an international review journal ; research reviews and patent abstracts N2 - Resurrection species are a group of land plants that can tolerate extreme desiccation of their vegetative tissues during harsh drought stress, and still quickly often within hours regain normal physiological and metabolic functions following rehydration. At the molecular level, this desiccation tolerance is attributed to basal cellular mechanisms including the constitutive expression of stress-associated genes and high levels of protective metabolites present already in the absence of stress, as well as to transcriptome and metabolome reconfigurations rapidly occurring during the initial phases of drought stress. Parts of this response are conferred by unique metabolites, including a diverse array of sugars, phenolic compounds, and polyols, some of which accumulate to high concentrations within the plant cell. In addition to drought stress, these metabolites are proposed to contribute to the protection against other abiotic stresses and to an increased oxidative stress tolerance. Recently, extracts of resurrection species and particular secondary metabolites therein were reported to display biological activities of importance to medicine, with e.g. antibacterial, anticancer, antifungal, and antiviral activities, rendering them possible candidates for the development of novel drug substances as well as for cosmetics. Herein, we provide an overview of the metabolite composition of resurrection species, summarize the latest reports related to the use of natural products from resurrection plants, and outline their potential for medical applications. (C) 2014 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/3.0/). KW - Antibacterial KW - Anticancer KW - Antifungal KW - Antiviral KW - Natural product KW - Resurrection plant KW - Secondary metabolite KW - Synthetic biology Y1 - 2014 U6 - https://doi.org/10.1016/j.biotechadv.2014.03.005 SN - 0734-9750 SN - 1873-1899 VL - 32 IS - 6 SP - 1091 EP - 1101 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Gliwicka, Marta A1 - Balazadeh, Salma A1 - Caldana, Camila A1 - Müller-Röber, Bernd A1 - Gaj, Malgorzata D. T1 - The use of multi-qPCR platform and tan1 mutant in identification of TF genes involved in somatic embryogenesis in Arabidopsis Y1 - 2009 UR - http://www.ib.uj.edu.pl/abc/index.php?d=06 SN - 0001-5296 ER - TY - JOUR A1 - Gliwicka, Marta A1 - Nowak, Katarzyna A1 - Balazadeh, Salma A1 - Müller-Röber, Bernd A1 - Gaj, Malgorzata D. T1 - Extensive Modulation of the Transcription Factor Transcriptome during Somatic Embryogenesis in Arabidopsis thaliana JF - PLoS one N2 - Molecular mechanisms controlling plant totipotency are largely unknown and studies on somatic embryogenesis (SE), the process through which already differentiated cells reverse their developmental program and become embryogenic, provide a unique means for deciphering molecular mechanisms controlling developmental plasticity of somatic cells. Among various factors essential for embryogenic transition of somatic cells transcription factors (TFs), crucial regulators of genetic programs, are believed to play a central role. Herein, we used quantitative real-time polymerase chain reaction (qRT-PCR) to identify TF genes affected during SE induced by in vitro culture in Arabidopsis thaliana. Expression profiles of 1,880 TFs were evaluated in the highly embryogenic Col-0 accession and the non-embryogenic tanmei/emb2757 mutant. Our study revealed 729 TFs whose expression changes during the 10-days incubation period of SE; 141 TFs displayed distinct differences in expression patterns in embryogenic versus non-embryogenic cultures. The embryo-induction stage of SE occurring during the first 5 days of culture was associated with a robust and dramatic change of the TF transcriptome characterized by the drastic up-regulation of the expression of a great majority (over 80%) of the TFs active during embryogenic culture. In contrast to SE induction, the advanced stage of embryo formation showed attenuation and stabilization of transcript levels of many TFs. In total, 519 of the SE-modulated TFs were functionally annotated and transcripts related with plant development, phytohormones and stress responses were found to be most abundant. The involvement of selected TFs in SE was verified using T-DNA insertion lines and a significantly reduced embryogenic response was found for the majority of them. This study provides comprehensive data focused on the expression of TF genes during SE and suggests directions for further research on functional genomics of SE. Y1 - 2013 U6 - https://doi.org/10.1371/journal.pone.0069261 SN - 1932-6203 VL - 8 IS - 7 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Gomez-Merino, Fernando Carlos A1 - Arana-Ceballos, Fernando Alberto A1 - Trejo-Tellez, L. I. A1 - Skirycz, Aleksandra A1 - Brearley, C. A. A1 - Dormann, P. A1 - Müller-Röber, Bernd T1 - Arabidopsis AtDGK7, the smallest member of plant diacylglycerol kinases (DGKs), displays unique biochemical features and saturates at low substrate concentration : the DGK inhibitor R59022 differentially affects AtDGK2 and AtDGK7 activity in vitro and alters plant growth and development N2 - Diacylglycerol kinase (DGK) regulates the level of the second messenger diacylglycerol and produces phosphatidic acid (PA), another signaling molecule. The Arabidopsis thaliana genome encodes seven putative diacylglycerol kinase isozymes (named AtDGK1 to -7), structurally falling into three major clusters. So far, enzymatic activity has not been reported for any plant Cluster II DGK. Here, we demonstrate that a representative of this cluster, AtDGK7, is biochemically active when expressed as a recombinant protein in Escherichia coli. AtDGK7, encoded by gene locus At4g30340, contains 374 amino acids with an apparent molecular mass of 41.2 kDa. AtDGK7 harbors an N-terminal catalytic domain, but in contrast to various characterized DGKs (including AtDGK2), it lacks a cysteine-rich domain at its N terminus, and, importantly, its C-terminal DGK accessory domain is incomplete. Recombinant AtDGK7 expressed in E. coli exhibits Michaelis-Menten type kinetics with 1,2-dioleoyl-sn-glycerol as substrate. AtDGK7 activity was affected by pH, detergents, and the DGK inhibitor R59022. We demonstrate that both AtDGK2 and AtDGK7 phosphorylate diacylglycerol molecular species that are typically found in plants, indicating that both enzymes convert physiologically relevant substrates. AtDGK7 is expressed throughout the Arabidopsis plant, but expression is strongest in flowers and young seedlings. Expression of AtDGK2 is transiently induced by wounding. R59022 at similar to 80 mu M inhibits root elongation and lateral root formation and reduces plant growth, indicating that DGKs play an important role in plant development Y1 - 2005 SN - 0021-9258 ER - TY - JOUR A1 - Gomez-Merino, Fernando Carlos A1 - Brearley, C. A. A1 - Ornatowska, Magdalena A1 - Abdel-Haliem, Mahmoud E. F. A1 - Zanor, Maria Ines A1 - Müller-Röber, Bernd T1 - AtDGK2, a novel diacylglycerol kinase from Arabidopsis thaliana, phosphorylates 1-stearoyl-2-arachidonoyl-sn- glycerol and 1,2-dioleoyl-sn-glycerol and exhibits cold-inducible gene expression N2 - Diacylglycerol kinase (DGK) phosphorylates diacylglycerol (DAG) to generate phosphatidic acid (PA). Both DAG and PA are implicated in signal transduction pathways. DGKs have been widely studied in animals, but their analysis in plants is fragmentary. Here, we report the cloning and biochemical characterization of AtDGK2, encoding DGK from Arabidopsis thaliana. AtDGK2 has a predicted molecular mass of 79.4 kDa and, like AtDGK1 previously reported, harbors two copies of a phorbol ester/DAG-binding domain in its N-terminal region. AtDGK2 belongs to a family of seven DGK genes in A. thaliana. AtDGK3 to AtDGK7 encode similar to55-kDa DGKs that lack a typical phorbol ester/DAG-binding domain. Phylogenetically, plant DGKs fall into three clusters. Members of all three clusters are widely expressed in vascular plants. Recombinant AtDGK2 was expressed in Escherichia coli and biochemically characterized. The enzyme phosphorylated 1,2-dioleoyl-sn-glycerol to yield PA, exhibiting Michaelis-Menten type kinetics. Estimated K-m and V-max values were 125 muM for DAG and 0.25 pmol of PA min(-1) mug(-1), respectively. The enzyme was maximally active at pH 7.2. Its activity was Mg2+-dependent and affected by the presence of detergents, salts, and the DGK inhibitor R59022, but not by Ca2+. AtDGK2 exhibited substrate preference for unsaturated DAG analogues (i.e. 1-stearoyl-2-arachidonoyl-sn-glycerol and 1,2- dioleoyl-sn-glycerol). The AtDGK2 gene is expressed in various tissues of the Arabidopsis plant, including leaves, roots, and flowers, as shown by Northern blot analysis and promoter-reporter gene fusions. We found that AtDGK2 is induced by exposure to low temperature (4degreesC), pointing to a role in cold signal transduction Y1 - 2004 SN - 0021-9258 ER - TY - JOUR A1 - Gupta, Saurabh A1 - Dong, Yanni A1 - Dijkwel, Paul P. A1 - Müller-Röber, Bernd A1 - Gechev, Tsanko S. T1 - Genome-Wide Analysis of ROS Antioxidant Genes in Resurrection Species Suggest an Involvement of Distinct ROS Detoxification Systems during Desiccation JF - International Journal of Molecular Sciences N2 - Abiotic stress is one of the major threats to plant crop yield and productivity. When plants are exposed to stress, production of reactive oxygen species (ROS) increases, which could lead to extensive cellular damage and hence crop loss. During evolution, plants have acquired antioxidant defense systems which can not only detoxify ROS but also adjust ROS levels required for proper cell signaling. Ascorbate peroxidase (APX), glutathione peroxidase (GPX), catalase (CAT) and superoxide dismutase (SOD) are crucial enzymes involved in ROS detoxification. In this study, 40 putative APX, 28 GPX, 16 CAT, and 41 SOD genes were identified from genomes of the resurrection species Boea hygrometrica, Selaginella lepidophylla, Xerophyta viscosa, and Oropetium thomaeum, and the mesophile Selaginella moellendorffi. Phylogenetic analyses classified the APX, GPX, and SOD proteins into five clades each, and CAT proteins into three clades. Using co-expression network analysis, various regulatory modules were discovered, mainly involving glutathione, that likely work together to maintain ROS homeostasis upon desiccation stress in resurrection species. These regulatory modules also support the existence of species-specific ROS detoxification systems. The results suggest molecular pathways that regulate ROS in resurrection species and the role of APX, GPX, CAT and SOD genes in resurrection species during stress. KW - abiotic stress KW - desiccation KW - resurrection plants KW - ROS KW - ascorbate peroxidase KW - glutathione peroxidase KW - catalase KW - superoxide dismutase Y1 - 2019 U6 - https://doi.org/10.3390/ijms20123101 SN - 1422-0067 SN - 1661-6596 VL - 20 IS - 12 PB - Molecular Diversity Preservation International CY - Basel ER - TY - JOUR A1 - Hasnat, Muhammad Abrar A1 - Zupok, Arkadiusz A1 - Olas-Apelt, Justyna Jadwiga A1 - Müller-Röber, Bernd A1 - Leimkühler, Silke T1 - A-type carrier proteins are involved in [4Fe-4S] cluster insertion into the radical S-adenosylmethionine protein MoaA for the synthesis of active molybdoenzymes JF - Journal of bacteriology N2 - Iron sulfur (Fe-S) clusters are important biological cofactors present in proteins with crucial biological functions, from photosynthesis to DNA repair, gene expression, and bioenergetic processes. For the insertion of Fe-S clusters into proteins, A-type carrier proteins have been identified. So far, three of them have been characterized in detail in Escherichia coli, namely, IscA, SufA, and ErpA, which were shown to partially replace each other in their roles in [4Fe-4S] cluster insertion into specific target proteins. To further expand the knowledge of [4Fe-4S] cluster insertion into proteins, we analyzed the complex Fe-S cluster-dependent network for the synthesis of the molybdenum cofactor (Moco) and the expression of genes encoding nitrate reductase in E. coli. Our studies include the identification of the A-type carrier proteins ErpA and IscA, involved in [4Fe-4S] cluster insertion into the radical Sadenosyl-methionine (SAM) enzyme MoaA. We show that ErpA and IscA can partially replace each other in their role to provide [4Fe-4S] clusters for MoaA. Since most genes expressing molybdoenzymes are regulated by the transcriptional regulator for fumarate and nitrate reduction (FNR) under anaerobic conditions, we also identified the proteins that are crucial to obtain an active FNR under conditions of nitrate respiration. We show that ErpA is essential for the FNR-dependent expression of the narGHJI operon, a role that cannot be compensated by IscA under the growth conditions tested. SufA does not appear to have a role in Fe-S cluster insertion into MoaA or FNR under anaerobic growth employing nitrate respiration, based on the low level of gene expression.
IMPORTANCE Understanding the assembly of iron-sulfur (Fe-S) proteins is relevant to many fields, including nitrogen fixation, photosynthesis, bioenergetics, and gene regulation. Remaining critical gaps in our knowledge include how Fe-S clusters are transferred to their target proteins and how the specificity in this process is achieved, since different forms of Fe-S clusters need to be delivered to structurally highly diverse target proteins. Numerous Fe-S carrier proteins have been identified in prokaryotes like Escherichia coli, including ErpA, IscA, SufA, and NfuA. In addition, the diverse Fe-S cluster delivery proteins and their target proteins underlie a complex regulatory network of expression, to ensure that both proteins are synthesized under particular growth conditions. KW - iron-sulfur clusters KW - Moco biosynthesis KW - MoaA KW - A-type carrier protein KW - FNR KW - nitrate reductase KW - molybdenum cofactor Y1 - 2021 U6 - https://doi.org/10.1128/JB.00086-21 SN - 1098-5530 VL - 203 IS - 12 PB - American Society for Microbiology CY - Washington ER - TY - JOUR A1 - Hochrein, Lena A1 - Mitchell, Leslie A. A1 - Schulz, Karina A1 - Messerschmidt, Katrin A1 - Müller-Röber, Bernd T1 - L-SCRaMbLE as a tool for light-controlled Cre-mediated recombination in yeast JF - Nature Communications N2 - The synthetic yeast genome constructed by the International Synthetic Yeast Sc2.0 consortium adds thousands of loxPsym recombination sites to all 16 redesigned chromosomes, allowing the shuffling of Sc2.0 chromosome parts by the Cre-loxP recombination system thereby enabling genome evolution experiments. Here, we present L-SCRaMbLE, a lightcontrolled Cre recombinase for use in the yeast Saccharomyces cerevisiae. L-SCRaMbLE allows tight regulation of recombinase activity with up to 179-fold induction upon exposure to red light. The extent of recombination depends on induction time and concentration of the chromophore phycocyanobilin (PCB), which can be easily adjusted. The tool presented here provides improved recombination control over the previously reported estradiol-dependent SCRaMbLE induction system, mediating a larger variety of possible recombination events in SCRaMbLE-ing a reporter plasmid. Thereby, L-SCRaMbLE boosts the potential for further customization and provides a facile application for use in the S. cerevisiae genome reengineering project Sc2.0 or in other recombination-based systems. Y1 - 2018 U6 - https://doi.org/10.1038/s41467-017-02208-6 SN - 2041-1723 VL - 9 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Johansson, Ingela A1 - Wulfetange, Klaas A1 - Poree, Fabien A1 - Michard, Erwan A1 - Gajdanowicz, Pawel A1 - Lacombe, Benoit A1 - Sentenac, Herve A1 - Thibaud, Jean-Baptiste A1 - Müller-Röber, Bernd A1 - Blatt, Michael R. A1 - Dreyer, Ingo T1 - External K+ modulates the activity of the Arabidopsis potassium channel SKOR via an unusual mechanism N2 - Plant outward-rectifying K+ channels mediate K+ efflux from guard cells during stomatal closure and from root cells into the xylem for root-shoot allocation of potassium (K). Intriguingly, the gating of these channels depends on the extracellular K+ concentration, although the ions carrying the current are derived from inside the cell. This K+ dependence confers a sensitivity to the extracellular K+ concentration ([K+]) that ensures that the channels mediate K+ efflux only, regardless of the [K+] prevailing outside. We investigated the mechanism of K+-dependent gating of the K+ channel SKOR of Arabidopsis by site-directed mutagenesis. Mutations affecting the intrinsic K+ dependence of gating were found to cluster in the pore and within the sixth transmembrane helix (S6), identifying an 'S6 gating domain' deep within the membrane. Mapping the SKOR sequence to the crystal structure of the voltage-dependent K+ channel KvAP from Aeropyrum pernix suggested interaction between the S6 gating domain and the base of the pore helix, a prediction supported by mutations at this site. These results offer a unique insight into the molecular basis for a physiologically important K+-sensory process in plants Y1 - 2006 UR - http://www3.interscience.wiley.com/cgi-bin/issn?DESCRIPTOR=PRINTISSN&VALUE=0960-7412 U6 - https://doi.org/10.1111/j.1365-313X.2006.02690.X SN - 0960-7412 ER - TY - JOUR A1 - John, Sheeba A1 - Olas, Justyna Jadwiga A1 - Müller-Röber, Bernd T1 - Regulation of alternative splicing in response to temperature variation in plants JF - Journal of experimental botany N2 - Plants have evolved numerous molecular strategies to cope with perturbations in environmental temperature, and to adjust growth and physiology to limit the negative effects of extreme temperature. One of the strategies involves alternative splicing of primary transcripts to encode alternative protein products or transcript variants destined for degradation by nonsense-mediated decay. Here, we review how changes in environmental temperature-cold, heat, and moderate alterations in temperature-affect alternative splicing in plants, including crops. We present examples of the mode of action of various temperature-induced splice variants and discuss how these alternative splicing events enable favourable plant responses to altered temperatures. Finally, we point out unanswered questions that should be addressed to fully utilize the endogenous mechanisms in plants to adjust their growth to environmental temperature. We also indicate how this knowledge might be used to enhance crop productivity in the future. KW - alternative splicing KW - ambient temperature KW - cold KW - heat KW - plants KW - stress KW - adaptation Y1 - 2021 U6 - https://doi.org/10.1093/jxb/erab232 SN - 0022-0957 SN - 1460-2431 VL - 72 IS - 18 SP - 6150 EP - 6163 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Kohler, B. A1 - Müller-Röber, Bernd T1 - Remote control - cell and organ communication within plants Y1 - 2004 ER - TY - JOUR A1 - Kreft, Oliver A1 - Georgieva, Radostina A1 - Bäumler, Hans A1 - Steup, Martin A1 - Müller-Röber, Bernd A1 - Sukhorukov, Gleb B. A1 - Möhwald, Helmuth T1 - Red blood cell templated polyelectrolyte capsules : a novel vehicle for the stable encapsulation of DNA and proteins N2 - A novel method for the encapsulation of biomacromolecules, such as nucleic acids and proteins, into polyelectrolyte microcapsules is described. Fluorescence-labelled double-stranded DNA and human serum albumin (HSA) are used as model substances for encapsulation in hollow microcapsules templated on human erythrocytes. The encapsulation procedure involves an intermediate drying C, step. The accumulation of DNA and HSA in the capsules is observed by confocal laser scanning microscopy, UV spectroscopy, and flourimetry. The mechanism of encapsulation is discussed Y1 - 2006 UR - http://www3.interscience.wiley.com/cgi-bin/jhome/10003270 U6 - https://doi.org/10.1002/marc.200500777 SN - 1022-1336 ER - TY - JOUR A1 - Köslin-Findeklee, Fabian A1 - Rizi, Vajiheh Safavi A1 - Becker, Martin A. A1 - Parra-Londono, Sebastian A1 - Arif, Muhammad A1 - Balazadeh, Salma A1 - Müller-Röber, Bernd A1 - Kunze, Reinhard A1 - Horst, Walter J. T1 - Transcriptomic analysis of nitrogen starvation- and cultivar-specific leaf senescence in winter oilseed rape (Brassica napus L.) JF - Plant science : an international journal of experimental plant biology N2 - High nitrogen (N) efficiency, characterized by high grain yield under N limitation, is an important agricultural trait in Brassica napus L. cultivars related to delayed senescence of older leaves during reproductive growth (a syndrome called stay-green). The aim of this study was thus to identify genes whose expression is specifically altered during N starvation-induced leaf senescence and that can be used as markers to distinguish cultivars at early stages of senescence prior to chlorophyll loss. To this end, the transcriptomes of leaves of two B. napus cultivars differing in stay-green characteristics and N efficiency were analyzed 4 days after the induction of senescence by either N starvation, leaf shading or detaching. In addition to N metabolism genes, N starvation mostly (and specifically) repressed genes related to photosynthesis, photorespiration and cell-wall structure, while genes related to mitochondrial electron transport and flavonoid biosynthesis were predominately up-regulated. A kinetic study over a period of 12 days with four B. napus cultivars differing in their stay-green characteristics confirmed the cultivar-specific regulation of six genes in agreement with their senescence behavior: the senescence regulator ANAC029, the anthocyanin synthesis-related genes ANS and DFR-like1, the ammonium transporter AMT1:4, the ureide transporter UPSS, and SPS1 involved in sucrose biosynthesis. The identified genes represent markers for the detection of cultivar-specific differences in N starvation-induced leaf senescence and can thus be employed as valuable tools in B. napus breeding. (C) 2015 Elsevier Ireland Ltd. All rights reserved. KW - Brassica napus KW - Genotypic differences KW - Leaf senescence KW - Molecular marker KW - N efficiency KW - Stay-green Y1 - 2015 U6 - https://doi.org/10.1016/j.plantsci.2014.11.018 SN - 0168-9452 VL - 233 SP - 174 EP - 185 PB - Elsevier CY - Clare 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 - 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 - Lin, W. H. A1 - Wang, Y. A1 - Müller-Röber, Bernd A1 - Brearley, C. A. A1 - Xu, Z. H. A1 - Xue, H. W. T1 - At5PTase13 modulates cotyledon vein development through regulating auxin homeostasis N2 - Phosphatidylinositol signaling pathway and the relevant metabolites are known to be critical to the modulation of different aspects of plant growth, development, and stress responses. Inositol polyphosphate 5-phosphatase is a key enzyme involved in phosphatidylinositol metabolism and is encoded by an At5PTase gene family in Arabidopsis thaliana. A previous study shows that At5PTase11 mediates cotyledon vascular development probably through the regulation of intracellular calcium levels. In this study, we provide evidence that At5PTase13 modulates the development of cotyledon veins through its regulation of auxin homeostasis. A T-DNA insertional knockout mutant, At5pt13-1, showed a defect in development of the cotyledon vein, which was rescued completely by exogenous auxin and in part by brassinolide, a steroid hormone. Furthermore, the mutant had reduced auxin content and altered auxin accumulation in seedlings revealed by the DR5:beta-glucuronidase fusion construct in seedlings. In addition, microarray analysis shows that the transcription of key genes responsible for auxin biosynthesis and transport was altered in At5pt13-1. The At5pt13-1 mutant was also less sensitive to auxin inhibition of root elongation. These results suggest that At5PTase13 regulates the homeostasis of auxin, a key hormone controlling vascular development in plants Y1 - 2005 SN - 0032-0889 ER - TY - JOUR A1 - Lotkowska, Magda E. A1 - Tohge, Takayuki A1 - Fernie, Alisdair R. A1 - Xue, Gang-Ping A1 - Balazadeh, Salma A1 - Müller-Röber, Bernd T1 - The Arabidopsis Transcription Factor MYB112 Promotes Anthocyanin Formation during Salinity and under High Light Stress JF - Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants N2 - MYB transcription factors (TFs) are important regulators of flavonoid biosynthesis in plants. Here, we report MYB112 as a formerly unknown regulator of anthocyanin accumulation in Arabidopsis (Arabidopsis thaliana). Expression profiling after chemically induced overexpression of MYB112 identified 28 up-and 28 down-regulated genes 5 h after inducer treatment, including MYB7 and MYB32, which are both induced. In addition, upon extended induction, MYB112 also positively affects the expression of PRODUCTION OF ANTHOCYANIN PIGMENT1, a key TF of anthocyanin biosynthesis, but acts negatively toward MYB12 and MYB111, which both control flavonol biosynthesis. MYB112 binds to an 8-bp DNA fragment containing the core sequence (A/T/G)(A/C) CC(A/T)(A/G/T)(A/C)(T/C). By electrophoretic mobility shift assay and chromatin immunoprecipitation coupled to quantitative polymerase chain reaction, we show that MYB112 binds in vitro and in vivo to MYB7 and MYB32 promoters, revealing them as direct downstream target genes. We further show that MYB112 expression is up-regulated by salinity and high light stress, environmental parameters that both require the MYB112 TF for anthocyanin accumulation under these stresses. In contrast to several other MYB TFs affecting anthocyanin biosynthesis, MYB112 expression is not controlled by nitrogen limitation or an excess of carbon. Thus, MYB112 constitutes a regulator that promotes anthocyanin accumulation under abiotic stress conditions. Y1 - 2015 U6 - https://doi.org/10.1104/pp.15.00605 SN - 0032-0889 SN - 1532-2548 VL - 169 IS - 3 SP - 1862 EP - 1880 PB - American Society of Plant Physiologists CY - Rockville ER - TY - GEN A1 - Lou, Ying A1 - Ma, Hui A1 - Lin, Wen-Hui A1 - Chu, Zhao-Quing A1 - Müller-Röber, Bernd A1 - Xu, Zhi-Hong A1 - Xue, Hong-Wei T1 - The highly charged region of plant beta-type phosphatidylinositol 4-kinase is involved in membrane targeting and phospholipid binding N2 - In Arabidopsis thaliana and Oryza sativa, two types of PI 4-kinase (PI4Ks) have been isolated and functionally characterized. The alpha-type PI4Ks (similar to 220 kDa) contain a PH domain, which is lacking in beta-type PI4Ks (similar to 120 kDa). beta-Type PI4Ks, exemplified by Arabidopsis AtPI4K beta and rice OsPI4K2, contain a highly charged repetitive segment designated PPC (Plant PI4K Charged) region, which is an unique domain only found in plant beta-type PI4Ks at present. The PPC region has a length of similar to 300 amino acids and harboring 11 (AtPI4K beta) and 14 (OsPI4K2) repeats, respectively, of a 20-aa motif. Studies employing a modified yeast-based "Sequence of Membrane- Targeting Detection'' system demonstrate that the PPC(OsPI4K2) region, as well as the former 8 and latter 6 repetitive motifs within the PPC region, are able to target fusion proteins to the plasma membrane. Further detection on the transiently expressed GFP fusion proteins in onion epidermal cells showed that the PPC(OsPI4K2) region alone, as well as the region containing repetitive motifs 1-8, was able to direct GFP to the plasma membrane, while the regions containing less repetitive motifs, i.e. 6, 4, 2 or single motif(s) led to predominantly intracellular localization. Agrobacterium-mediated transient expression of PPC-GFP fusion protein further confirms the membrane-targeting capacities of PPC region. In addition, the predominant plasma membrane localization of AtPI4Kb was mediated by the PPC region. Recombinant PPC peptide, expressed in E. coli, strongly binds phosphatidic acid, PI and PI4P, but not phosphatidylcholine, PI5P, or PI(4,5) P-2 in vitro, providing insights into potential mechanisms for regulating sub- cellular localization and lipid binding for the plant beta-type PI4Ks Y1 - 2006 UR - http://www.springerlink.com/content/100330 U6 - https://doi.org/10.1007/s11103-005-5548-x SN - 0167-4412 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 - Lukoszek, Radoslaw A1 - Müller-Röber, Bernd A1 - Ignatova, Zoya T1 - Interplay between polymerase II- and polymerase III-assisted expression of overlapping genes JF - FEBS letters : the journal for rapid publication of short reports in molecular biosciences N2 - Up to 15% of the genes in different genomes overlap. This architecture, although beneficial for the genome size, represents an obstacle for simultaneous transcription of both genes. Here we analyze the interference between RNA-polymerase II (Pol II) and RNA-polymerase III (Pol III) when transcribing their target genes encoded on opposing strands within the same DNA fragment in Arabidopsis thaliana. The expression of a Pol II-dependent protein-coding gene negatively correlated with the transcription of a Pol III-dependent, tRNA-coding gene set. We suggest that the architecture of the overlapping genes introduces an additional layer of control of gene expression. (C) 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved. KW - Gene expression KW - Transcription KW - tRNA KW - Nested and overlapping genes KW - Arabidopsis thaliana Y1 - 2013 U6 - https://doi.org/10.1016/j.febslet.2013.09.033 SN - 0014-5793 SN - 1873-3468 VL - 587 IS - 22 SP - 3692 EP - 3695 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Machens, Fabian A1 - Balazadeh, Salma A1 - Müller-Röber, Bernd A1 - Messerschmidt, Katrin T1 - Synthetic Promoters and Transcription Factors for Heterologous Protein Expression in Saccharomyces cerevisiae JF - Frontiers in Bioengineering and Biotechnology N2 - Orthogonal systems for heterologous protein expression as well as for the engineering of synthetic gene regulatory circuits in hosts like Saccharomyces cerevisiae depend on synthetic transcription factors (synTFs) and corresponding cis-regulatory binding sites. We have constructed and characterized a set of synTFs based on either transcription activator-like effectors or CRISPR/Cas9, and corresponding small synthetic promoters (synPs) with minimal sequence identity to the host’s endogenous promoters. The resulting collection of functional synTF/synP pairs confers very low background expression under uninduced conditions, while expression output upon induction of the various synTFs covers a wide range and reaches induction factors of up to 400. The broad spectrum of expression strengths that is achieved will be useful for various experimental setups, e.g., the transcriptional balancing of expression levels within heterologous pathways or the construction of artificial regulatory networks. Furthermore, our analyses reveal simple rules that enable the tuning of synTF expression output, thereby allowing easy modification of a given synTF/synP pair. This will make it easier for researchers to construct tailored transcriptional control systems. KW - JUB1 KW - synthetic biology KW - transcriptional regulation KW - gene expression KW - synthetic circuits KW - dead Cas9 KW - chimeric transcription factors Y1 - 2017 U6 - https://doi.org/10.3389/fbioe.2017.00063 SN - 2296-4185 VL - 5 SP - 1 EP - 11 PB - Frontiers CY - Lausanne ER - TY - JOUR A1 - Maitrejean, Marie A1 - Wudick, Michael M. A1 - Völker, Camilla A1 - Prinsi, Bhakti A1 - Müller-Röber, Bernd A1 - Czempinski, Katrin A1 - Pedrazzini, Emanuela A1 - Vitale, Alessandro T1 - Assembly and sorting of the tonoplast potassium channel AtTPK1 and its turnover by internalization into the Vacuole JF - Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants N2 - The assembly, sorting signals, and turnover of the tonoplast potassium channel AtTPK1 of Arabidopsis (Arabidopsis thaliana) were studied. We used transgenic Arabidopsis expressing a TPK1-green fluorescent protein (GFP) fusion or protoplasts transiently transformed with chimeric constructs based on domain exchange between TPK1 and TPK4, the only TPK family member not located at the tonoplast. The results show that TPK1-GFP is a dimer and that the newly synthesized polypeptides transiently interact with a thus-far unidentified 20-kD polypeptide. A subset of the TPK1-TPK4 chimeras were unable to assemble correctly and these remained located in the endoplasmic reticulum where they interacted with the binding protein chaperone. Therefore, TPK1 must assemble correctly to pass endoplasmic reticulum quality control. Substitution of the cytosolic C terminus of TPK4 with the corresponding domain of TPK1 was sufficient to allow tonoplast delivery, indicating that this domain contains tonoplast sorting information. Pulse-chase labeling indicated that TPK1-GFP has a half-life of at least 24 h. Turnover of the fusion protein involves internalization into the vacuole where the GFP domain is released. This indicates a possible mechanism for the turnover of tonoplast proteins. Y1 - 2011 U6 - https://doi.org/10.1104/pp.111.177816 SN - 0032-0889 VL - 156 IS - 4 SP - 1783 EP - 1796 PB - American Society of Plant Physiologists CY - Rockville ER - TY - JOUR A1 - Matallana-Ramirez, Lilian P. A1 - Rauf, Mamoona A1 - Farage-Barhom, Sarit A1 - Dortay, Hakan A1 - Xue, Gang-Ping A1 - Droege-Laser, Wolfgang A1 - Lers, Amnon A1 - Balazadeh, Salma A1 - Müller-Röber, Bernd T1 - NAC Transcription Factor ORE1 and Senescence-Induced BIFUNCTIONAL NUCLEASE1 (BFN1) Constitute a Regulatory Cascade in Arabidopsis JF - Molecular plant N2 - The NAC transcription factor ORE1 is a key regulator of senescence in Arabidopsis thaliana. Here, we demonstrate that senescence-induced and cell death-associated BIFUNCTIONAL NUCLEASE1 (BFN1) is a direct downstream target of ORE1, revealing a previously unknown regulatory cascade.Senescence is a highly regulated process that involves the action of a large number of transcription factors. The NAC transcription factor ORE1 (ANAC092) has recently been shown to play a critical role in positively controlling senescence in Arabidopsis thaliana; however, no direct target gene through which it exerts its molecular function has been identified previously. Here, we report that BIFUNCTIONAL NUCLEASE1 (BFN1), a well-known senescence-enhanced gene, is directly regulated by ORE1. We detected elevated expression of BFN1 already 2 h after induction of ORE1 in estradiol-inducible ORE1 overexpression lines and 6 h after transfection of Arabidopsis mesophyll cell protoplasts with a 35S:ORE1 construct. ORE1 and BFN1 expression patterns largely overlap, as shown by promoterreporter gene (GUS) fusions, while BFN1 expression in senescent leaves and the abscission zones of maturing flower organs was virtually absent in ore1 mutant background. In vitro binding site assays revealed a bipartite ORE1 binding site, similar to that of ORS1, a paralog of ORE1. A bipartite ORE1 binding site was identified in the BFN1 promoter; mutating the cis-element within the context of the full-length BFN1 promoter drastically reduced ORE1-mediated transactivation capacity in transiently transfected Arabidopsis mesophyll cell protoplasts. Furthermore, chromatin immunoprecipitation (ChIP) demonstrates in vivo binding of ORE1 to the BFN1 promoter. We also demonstrate binding of ORE1 in vivo to the promoters of two other senescence-associated genes, namely SAG29/SWEET15 and SINA1, supporting the central role of ORE1 during senescence. KW - Arabidopsis thaliana KW - senescence KW - transcription factor KW - ORE1 KW - BFN1 KW - promoter Y1 - 2013 U6 - https://doi.org/10.1093/mp/sst012 SN - 1674-2052 VL - 6 IS - 5 SP - 1438 EP - 1452 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Mehrnia, Mohammad A1 - Balazadeh, Salma A1 - Zanor, Maria-Ines A1 - Müller-Röber, Bernd T1 - EBE, an AP2/ERF transcription factor highly expressed in proliferating cells, affects shoot architecture in arabidopsis JF - Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants N2 - We report about ERF BUD ENHANCER (EBE; At5g61890), a transcription factor that affects cell proliferation as well as axillary bud outgrowth and shoot branching in Arabidopsis (Arabidopsis thaliana). EBE encodes a member of the APETALA2/ETHYLENE RESPONSE FACTOR (AP2/ERF) transcription factor superfamily; the gene is strongly expressed in proliferating cells and is rapidly and transiently up-regulated in axillary meristems upon main stem decapitation. Overexpression of EBE promotes cell proliferation in growing calli, while the opposite is observed in EBE-RNAi lines. EBE overexpression also stimulates axillary bud formation and outgrowth, while repressing it results in inhibition of bud growth. Global transcriptome analysis of estradiol-inducible EBE overexpression lines revealed 48 EBE early-responsive genes, of which 14 were up-regulated and 34 were downregulated. EBE activates several genes involved in cell cycle regulation and dormancy breaking, including D-type cyclin CYCD3; 3, transcription regulator DPa, and BRCA1-ASSOCIATED RING DOMAIN1. Among the down-regulated genes were DORMANCY-ASSOCIATED PROTEIN1 (AtDRM1), AtDRM1 homolog, MEDIATOR OF ABA-REGULATED DORMANCY1, and ZINC FINGER HOMEODOMAIN5. Our data indicate that the effect of EBE on shoot branching likely results from an activation of genes involved in cell cycle regulation and dormancy breaking. Y1 - 2013 U6 - https://doi.org/10.1104/pp.113.214049 SN - 0032-0889 VL - 162 IS - 2 SP - 842 EP - 857 PB - American Society of Plant Physiologists CY - Rockville ER -