TY - JOUR A1 - Allu, Annapurna Devi A1 - Simancas, Barbara A1 - Balazadeh, Salma A1 - Munne-Bosch, Sergi T1 - Defense-Related Transcriptional Reprogramming in Vitamin E-Deficient Arabidopsis Mutants Exposed to Contrasting Phosphate Availability JF - Frontiers in plant science N2 - Vitamin E inhibits the propagation of lipid peroxidation and helps protecting photosystem II from photoinhibition, but little is known about its possible role in plant response to Pi availability. Here, we aimed at examining the effect of vitamin E deficiency in Arabidopsis thaliana vte mutants on phytohormone contents and the expression of transcription factors in plants exposed to contrasting Pi availability. Plants were subjected to two doses of Pi, either unprimed (controls) or previously exposed to low Pi (primed). In the wild type, alpha-tocopherol contents increased significantly in response to repeated periods of low Pi, which was paralleled by increased growth, indicative of a priming effect. This growth-stimulating effect was, however, abolished in vte mutants. Hormonal profiling revealed significant effects of Pi availability, priming and genotype on the contents of jasmonates and salicylates; remarkably, vte mutants showed enhanced accumulation of both hormones under low Pi. Furthermore, expression profiling of 1,880 transcription factors by qRT-PCR revealed a pronounced effect of priming on the transcript levels of 45 transcription factors mainly associated with growth and stress in wild-type plants in response to low Pi availability; while distinct differences in the transcriptional response were detected in vte mutants. We conclude that alpha-tocopherol plays a major role in the response of plants to Pi availability not only by protecting plants from photo-oxidative stress, but also by exerting a control over growth-and defense-related transcriptional reprogramming and hormonal modulation. KW - antioxidants KW - photosystem II KW - plastochromanol-8 KW - priming KW - retrograde signaling KW - tocochromanols KW - vitamin E Y1 - 2017 U6 - https://doi.org/10.3389/fpls.2017.01396 SN - 1664-462X VL - 8 PB - Frontiers Research Foundation CY - Lausanne 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 - Ebrahimian-Motlagh, Saghar A1 - Ribone, Pamela A. A1 - Thirumalaikumar, Venkatesh P. A1 - Allu, Annapurna Devi A1 - Chan, Raquel L. A1 - Mueller-Roeber, Bernd A1 - Balazadeh, Salma T1 - JUNGBRUNNEN1 Confers Drought Tolerance Downstream of the HD-Zip I Transcription Factor AtHB13 JF - Frontiers in plant science N2 - Low water availability is the major environmental factor limiting growth and productivity of plants and crops and is therefore considered of high importance for agriculture affected by climate change. Identifying regulatory components controlling the response and tolerance to drought stress is thus of major importance. The NAC transcription factor (TF) JUNGBRUNNEN1 (JUB1) from Arabidopsis thaliana extends leaf longevity under non-stress growth conditions, lowers cellular hydrogen peroxide (H2O2) level, and enhances tolerance against heat stress and salinity. Here, we additionally find that JUB1 strongly increases tolerance to drought stress in Arabidopsis when expressed from both, a constitutive (CaMV 35S) and an abiotic stress-induced (RD29A) promoter. Employing a yeast one-hybrid screen we identified HD-Zip class I TF AtHB13 as an upstream regulator of JUB1. AtHB13 has previously been reported to act as a positive regulator of drought tolerance. AtHB13 and JUB1 thereby establish a joint drought stress control module. KW - Arabidopsis KW - transcription factor KW - drought KW - JUB1 KW - HB13 Y1 - 2017 U6 - https://doi.org/10.3389/fpls.2017.02118 SN - 1664-462X VL - 8 PB - Frontiers Research Foundation CY - Lausanne ER - TY - GEN 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 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. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 393 KW - JUB1 KW - chimeric transcription factors KW - dead Cas9 KW - gene expression KW - synthetic biology KW - synthetic circuits KW - transcriptional regulation Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-403804 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 - Naseri, Gita A1 - Balazadeh, Salma A1 - Machens, Fabian A1 - Kamranfar, Iman A1 - Messerschmidt, Katrin A1 - Müller-Röber, Bernd T1 - Plant-Derived Transcription Factors for Orthologous Regulation of Gene Expression in the Yeast Saccharomyces cerevisiae JF - ACS synthetic biology N2 - Control of gene expression by transcription factors (TFs) is central in many synthetic biology projects for which a tailored expression of one or multiple genes is often needed. As TFs from evolutionary distant organisms are unlikely to affect gene expression in a host of choice, they represent excellent candidates for establishing orthogonal control systems. To establish orthogonal regulators for use in yeast (Saccharomyces cerevisiae), we chose TFs from the plant Arabidopsis thaliana. We established a library of 106 different combinations of chromosomally integrated TFs, activation domains (yeast GAL4 AD, herpes simplex virus VP64, and plant EDLL) and synthetic promoters harboring cognate cis regulatory motifs driving a yEGFP reporter. Transcriptional output of the different driver/reporter combinations varied over a wide spectrum, with EDLL being a considerably stronger transcription activation domain in yeast than the GAL4 activation domain, in particular when fused to Arabidopsis NAC TFs. Notably, the strength of several NAC-EDLL fusions exceeded that of the strong yeast TDH3 promoter by 6- to 10-fold. We furthermore show that plant TFs can be used to build regulatory systems encoded by centromeric or episomal plasmids. Our library of TF-DNA binding site combinations offers an excellent tool for diverse synthetic biology applications in yeast. KW - Arabidopsis thaliana KW - artificial transcription factor KW - NAC transcription factor KW - synthetic biology KW - plant Y1 - 2017 U6 - https://doi.org/10.1021/acssynbio.7b00094 SN - 2161-5063 VL - 6 SP - 1742 EP - 1756 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Shahnejat-Bushehri, Sara A1 - Allu, Annapurna Devi A1 - Mehterov, Nikolay A1 - Thirumalaikumar, Venkatesh P. A1 - Alseekh, Saleh A1 - Fernie, Alisdair R. A1 - Mueller-Roeber, Bernd A1 - Balazadeh, Salma T1 - Arabidopsis NAC Transcription Factor JUNGBRUNNEN1 Exerts Conserved Control Over Gibberellin and Brassinosteroid Metabolism and Signaling Genes in Tomato JF - Frontiers in plant science N2 - The Arabidopsis thaliana NAC transcription factor JUNGBRUNNEN1 (AtJUB1) regulates growth by directly repressing GA3ox1 and DWF4, two key genes involved in gibberellin (GA) and brassinosteroid (BR) biosynthesis, respectively, leading to GA and BR deficiency phenotypes. AtJUB1 also reduces the expression of PIF4, a bHLH transcription factor that positively controls cell elongation, while it stimulates the expression of DELLA genes, which are important repressors of growth. Here, we extend our previous findings by demonstrating that AtJUB1 induces similar GA and BR deficiency phenotypes and changes in gene expression when overexpressed in tomato (Solanum lycopersicum). Importantly, and in accordance with the growth phenotypes observed, AtJUB1 inhibits the expression of growth-supporting genes, namely the tomato orthologs of GA3ox1, DWF4 and PIF4, but activates the expression of DELLA orthologs, by directly binding to their promoters. Overexpression of AtJUB1 in tomato delays fruit ripening, which is accompanied by reduced expression of several ripeningrelated genes, and leads to an increase in the levels of various amino acids (mostly proline, beta-alanine, and phenylalanine), gamma-aminobutyric acid (GABA), and major organic acids including glutamic acid and aspartic acid. The fact that AtJUB1 exerts an inhibitory effect on the GA/BR biosynthesis and PIF4 genes but acts as a direct activator of DELLA genes in both, Arabidopsis and tomato, strongly supports the model that the molecular constituents of the JUNGBRUNNEN1 growth control module are considerably conserved across species. KW - Arabidopsis KW - tomato KW - fruit KW - growth KW - transcription factor KW - gibberellic acid KW - brassinosteroid KW - DELLA proteins Y1 - 2017 U6 - https://doi.org/10.3389/fpls.2017.00214 SN - 1664-462X VL - 8 PB - Frontiers Research Foundation CY - Lausanne 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 - 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 JF - Plant Biotechnology Journal 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. KW - Arabidopsis KW - tomato KW - transcription factor KW - drought KW - reactive oxygen species KW - DELLA Y1 - 2017 U6 - https://doi.org/10.1111/pbi.12776 SN - 1467-7644 SN - 1467-7652 VL - 16 IS - 2 SP - 354 EP - 366 PB - Wiley CY - Hoboken ER -