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 - Benina, Maria A1 - Obata, Toshihiro A1 - Mehterov, Nikolay A1 - Ivanov, Ivan A1 - Petrov, Veselin A1 - Toneva, Valentina A1 - Fernie, Alisdair R. A1 - Gechev, Tsanko S. T1 - Comparative metabolic profiling of Haberlea rhodopensis, Thellungiella halophyla, and Arabidopsis thaliana exposed to low temperature JF - Frontiers in plant science N2 - Haberlea rhodopensis is a resurrection species with extreme resistance to drought stress and desiccation but also with ability to withstand low temperatures and freezing stress. In order to identify biochemical strategies which contribute to Haberlea's remarkable stress tolerance, the metabolic reconfiguration of H. rhodopensis during low temperature (4 degrees C) and subsequent return to optimal temperatures (21 degrees C) was investigated and compared with that of the stress tolerant Thellungiella halophyla and the stress sensitive Arabidopsis thaliana. Metabolic analysis by GC-MS revealed intrinsic differences in the metabolite levels of the three species even at 21 degrees C. H. rhodopensis had significantly more raffinose, melibiose, trehalose, rhamnose, myo-inositol, sorbitol, galactinol, erythronate, threonate, 2-oxoglutarate, citrate, and glycerol than the other two species. A. thaliana had the highest levels of putrescine and fumarate, while T halophila had much higher levels of several amino acids, including alanine, asparagine, beta-alanine, histidine, isoleucine, phenylalanine, serine, threonine, and valine. In addition, the three species responded differently to the low temperature treatment and the subsequent recovery, especially with regard to the sugar metabolism. Chilling induced accumulation of maltose in H. rhodopensis and raffinose in A. thaliana but the raffinose levels in low temperature exposed Arabidopsis were still much lower than these in unstressed Haberlea. While all species accumulated sucrose during chilling, that accumulation was transient in H. rhodopensis and A. thaliana but sustained in T halophila after the return to optimal temperature. Thus, Haberlea's metabolome appeared primed for chilling stress but the low temperature acclimation induced additional stress-protective mechanisms. A diverse array of sugars, organic acids, and polyols constitute Haberlea's main metabolic defence mechanisms against chilling, while accumulation of amino acids and amino acid derivatives contribute to the low temperature acclimation in Arabidopsis and Thellungiella. Collectively, these results show inherent differences in the metabolomes under the ambient temperature and the strategies to respond to low temperature in the three species. KW - Arabidopsis thaliana KW - Haberlea rhodopensis KW - low temperature stress KW - metabolite profiling KW - Thellungiella halophila Y1 - 2013 U6 - https://doi.org/10.3389/fpls.2013.00499 SN - 1664-462X VL - 4 IS - 1 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Petrov, Veselin A1 - Schippers, Jos A1 - Benina, Maria A1 - Minkov, Ivan A1 - Müller-Röber, Bernd A1 - Gechev, Tsanko S. T1 - In search for new players of the oxidative stress network by phenotyping an Arabidopsis T-DNA mutant collection on reactive oxygen species-eliciting chemicals JF - Plant omics N2 - The ability of some chemical compounds to cause oxidative stress offers a fast and convenient way to study the responses of plants to reactive oxygen species (ROS). In order to unveil potential novel genetic players of the ROS-regulatory network, a population of similar to 2,000 randomly selected Arabidopsis thaliana T-DNA insertion mutants was screened for ROS sensitivity/resistance by growing seedlings on agar medium supplemented with stress-inducing concentrations of the superoxide-eliciting herbicide methyl viologen or the catalase inhibitor 3-amino-triazole. A semi-robotic setup was used to capture and analyze images of the chemically treated seedlings which helped interpret the screening results by providing quantitative information on seedling area and healthy-to-chlorotic tissue ratios for data verification. A ROS-related phenotype was confirmed in three of the initially selected 33 mutant candidates, which carry T-DNA insertions in genes encoding a Ring/Ubox superfamily protein, ABI5 binding protein 1 (AFP1), previously reported to be involved in ABA signaling, and a protein of unknown function, respectively. In addition, we identified six mutants, most of which have not been described yet, that are related to growth or chloroplast development and show defects in a ROS-independent manner. Thus, semi-automated image capturing and phenotyping applied on publically available T-DNA insertion collections adds a simple means for discovering novel mutants in complex physiological processes and identifying the genes involved. KW - growth KW - image analysis KW - methyl viologen KW - LemnaTec KW - screening KW - superoxide Y1 - 2013 SN - 1836-0661 VL - 6 IS - 1 SP - 46 EP - 54 PB - Southern Cross Publ. CY - Lismore ER - TY - JOUR A1 - Ivanov, Ivan A1 - Benina, Maria A1 - Petrov, Veselin A1 - Gechev, Tsanko S. A1 - Toneva, Valentina T1 - Metabolic responses of gloxinia perennis to dehydration and rehydration JF - COMPTES RENDUS DE L ACADEMIE BULGARE DES SCIENCES N2 - Gloxinia perennis is a species from the family Gesneriaceae with little known physiology, particularly in respect to responses to dehydration. G. perennis survived water deprivation for a month and then quickly recovered upon rehydration. The slow loss of water was in contrast with the quick dehydration of other Gesnerian species - Boea hygrometrica, Ramonda serbica, and Haber lea rhodopensis. Furthermore, a significant difference between older and younger leaves of G. perennis was observed. While the relative water content in the early stages of water deprivation was reduced to 65% in the old leaves, it was not or slightly reduced in the young ones, implying a mechanism that protects specifically the younger leaves from dehydration. Water deprivation induced accumulation of gama-aminobutyric acid and sugars like sucrose and raffinose, but decreased the levels of amino acids such as glycine, leucine, and isoleucine. The levels of these amino acids recovered after rehydration and in some cases like glycine and isoleucine were even higher in rehydrated leaves compared with unstressed controls. We conclude that G.perennis can survive prolonged drought stress but its responses to dehydration are different from the resurrection species from Gesneriaceae. All this makes G. perennis a good model that can be used for comparative genomics and metabolomics of Gesneriads exposed to desiccation. KW - Gloxinia perennis KW - drought stress KW - metabolome analysis Y1 - 2014 SN - 1310-1331 VL - 67 IS - 12 SP - 1657 EP - 1662 PB - Publ. House of the Bulgarian Acad. of Sciences CY - Sofia 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 - GEN 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 T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe 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. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 778 KW - beta-oxidation KW - craterostigma-plantagineum KW - photosynthetic apparatus KW - transcription factors KW - lipid-metabolism KW - leaf senescence KW - fatty-acid KW - arabidopsis KW - chlorophyll KW - stress Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-437588 IS - 778 SP - 1319 EP - 1338 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 - 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 -