TY - JOUR A1 - Omidbakhshfard, Mohammad Amin A1 - Fujikura, Ushio A1 - Olas, Justyna Jadwiga A1 - Xue, Gang-Ping A1 - Balazadeh, Salma A1 - Mueller-Roeber, Bernd T1 - GROWTH-REGULATING FACTOR 9 negatively regulates arabidopsis leaf growth by controlling ORG3 and restricting cell proliferation in leaf primordia JF - PLoS Genetics : a peer-reviewed, open-access journal N2 - Leaf growth is a complex process that involves the action of diverse transcription factors (TFs) and their downstream gene regulatory networks. In this study, we focus on the functional characterization of the Arabidopsis thaliana TF GROWTH-REGULATING FACTOR9 (GRF9) and demonstrate that it exerts its negative effect on leaf growth by activating expression of the bZIP TF OBP3-RESPONSIVE GENE 3 (ORG3). While grf9 knockout mutants produce bigger incipient leaf primordia at the shoot apex, rosette leaves and petals than the wild type, the sizes of those organs are reduced in plants overexpressing GRF9 (GRF9ox). Cell measurements demonstrate that changes in leaf size result from alterations in cell numbers rather than cell sizes. Kinematic analysis and 5-ethynyl-2'-deoxyuridine (EdU) incorporation assay revealed that GRF9 restricts cell proliferation in the early developing leaf. Performing in vitro binding site selection, we identified the 6-base motif 5'-CTGACA-3' as the core binding site of GRF9. By global transcriptome profiling, electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) we identified ORG3 as a direct downstream, and positively regulated target of GRF9. Genetic analysis of grf9 org3 and GRF9ox org3 double mutants reveals that both transcription factors act in a regulatory cascade to control the final leaf dimensions by restricting cell number in the developing leaf. Y1 - 2018 U6 - https://doi.org/10.1371/journal.pgen.1007484 SN - 1553-7404 VL - 14 IS - 7 PB - PLoS CY - San Fransisco 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 - Shubchynskyy, Volodymyr A1 - Boniecka, Justyna A1 - Schweighofer, Alois A1 - Simulis, Justinas A1 - Kvederaviciute, Kotryna A1 - Stumpe, Michael A1 - Mauch, Felix A1 - Balazadeh, Salma A1 - Müller-Röber, Bernd A1 - Boutrot, Freddy A1 - Zipfel, Cyril A1 - Meskiene, Irute T1 - Protein phosphatase AP2C1 negatively regulates basal resistance and defense responses to Pseudomonas syringae JF - Journal of experimental botany N2 - Mitogen-activated protein kinases (MAPKs) mediate plant immune responses to pathogenic bacteria. However, less is known about the cell autonomous negative regulatory mechanism controlling basal plant immunity. We report the biological role of Arabidopsis thaliana MAPK phosphatase AP2C1 as a negative regulator of plant basal resistance and defense responses to Pseudomonas syringae. AP2C2, a closely related MAPK phosphatase, also negatively controls plant resistance. Loss of AP2C1 leads to enhanced pathogen-induced MAPK activities, increased callose deposition in response to pathogen-associated molecular patterns or to P. syringae pv. tomato (Pto) DC3000, and enhanced resistance to bacterial infection with Pto. We also reveal the impact of AP2C1 on the global transcriptional reprogramming of transcription factors during Pto infection. Importantly, ap2c1 plants show salicylic acid-independent transcriptional reprogramming of several defense genes and enhanced ethylene production in response to Pto. This study pinpoints the specificity of MAPK regulation by the different MAPK phosphatases AP2C1 and MKP1, which control the same MAPK substrates, nevertheless leading to different downstream events. We suggest that precise and specific control of defined MAPKs by MAPK phosphatases during plant challenge with pathogenic bacteria can strongly influence plant resistance. KW - Callose KW - defense genes KW - MAPK KW - MAPK phosphatase KW - PAMP KW - PP2C phosphatase KW - Pseudomonas syringae KW - salicylic acid KW - transcription factors Y1 - 2017 U6 - https://doi.org/10.1093/jxb/erw485 SN - 0022-0957 SN - 1460-2431 VL - 68 IS - 5 SP - 1169 EP - 1183 PB - Oxford Univ. Press CY - Oxford ER - TY - GEN A1 - Thirumalaikumar, Venkatesh P. A1 - Devkar, Vikas A1 - Mehterov, Nikolay A1 - Ali, Shawkat A1 - Ozgur, Rengin A1 - Turkan, Ismail A1 - Müller-Röber, Bernd A1 - Balazadeh, Salma T1 - NAC transcription factor JUNGBRUNNEN1 enhances drought tolerance in tomato T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - Water deficit (drought stress) massively restricts plant growth and the yield of crops; reducing the deleterious effects of drought is therefore of high agricultural relevance. Drought triggers diverse cellular processes including the inhibition of photosynthesis, the accumulation of cell‐damaging reactive oxygen species and gene expression reprogramming, besides others. Transcription factors (TF) are central regulators of transcriptional reprogramming and expression of many TF genes is affected by drought, including members of the NAC family. Here, we identify the NAC factor JUNGBRUNNEN1 (JUB1) as a regulator of drought tolerance in tomato (Solanum lycopersicum). Expression of tomato JUB1 (SlJUB1) is enhanced by various abiotic stresses, including drought. Inhibiting SlJUB1 by virus‐induced gene silencing drastically lowers drought tolerance concomitant with an increase in ion leakage, an elevation of hydrogen peroxide (H2O2) levels and a decrease in the expression of various drought‐responsive genes. In contrast, overexpression of AtJUB1 from Arabidopsis thaliana increases drought tolerance in tomato, alongside with a higher relative leaf water content during drought and reduced H2O2 levels. AtJUB1 was previously shown to stimulate expression of DREB2A, a TF involved in drought responses, and of the DELLA genes GAI and RGL1. We show here that SlJUB1 similarly controls the expression of the tomato orthologs SlDREB1, SlDREB2 and SlDELLA. Furthermore, AtJUB1 directly binds to the promoters of SlDREB1, SlDREB2 and SlDELLA in tomato. Our study highlights JUB1 as a transcriptional regulator of drought tolerance and suggests considerable conservation of the abiotic stress‐related gene regulatory networks controlled by this NAC factor between Arabidopsis and tomato. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 568 KW - Arabidopsis KW - tomato KW - transcription factor KW - drought KW - reactive oxygen species KW - DELLA Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-423908 SN - 1866-8372 IS - 568 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 - 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 - THES A1 - Balazadeh, Salma T1 - Molecular and physiological analysis of leaf senescence in Arabidopsis thaliana Y1 - 2008 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 - 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 - Sakuraba, Yasuhito A1 - Balazadeh, Salma A1 - Tanaka, Ryouichi A1 - Müller-Röber, Bernd A1 - Tanaka, Ayumi T1 - Overproduction of Chl b retards senescence through transcriptional reprogramming in arabidopsis JF - Plant & cell physiology N2 - Leaf senescence is a developmentally and environmentally regulated process which includes global changes in gene expression. Using Arabidopsis as a model, we modified Chl arrangement in photosystems by overexpressing the catalytic domain (the C domain) of chlorophyllide a oxygenase (CAO) fused with the linker domain (the B domain) of CAO and green fluorescent protein (GFP). In these plants (referred to as the BCG plants for the B and C domains of CAO and GFP), the Chl a/b ratio was drastically decreased and Chl b was incorporated into core antenna complexes. The BCG plants exhibited a significant delay of both developmental and dark-induced leaf senescence. The photosynthetic apparatus, CO2 fixation enzymes and the chloroplast structure were lost in wild-type plants during senescence, while BCG plants retained them longer than the wild type. Large-scale quantitative real-time PCR analyses of 1,880 transcription factor (TF) genes showed that 241 TFs are differentially expressed between BCG plants and wild-type plants at senescence, similar to 40% of which are known senescence-associated genes (SAGs). Expression profiling also revealed the down-regulation of a large number of additional non-TF SAGs. In contrast, genes involved in photosynthesis were up-regulated, while those encoding Chl degradation enzymes were down-regulated in BCG plants. These results demonstrate that alteration of pigment composition in the photosynthetic apparatus retards senescence through transcriptional reprogramming. KW - Arabidopsis KW - Chloroplast KW - Chlorophyllide a oxygenase KW - Photosynthesis KW - Senescence Y1 - 2012 U6 - https://doi.org/10.1093/pcp/pcs006 SN - 0032-0781 VL - 53 IS - 3 SP - 505 EP - 517 PB - Oxford Univ. Press CY - Oxford ER -