@article{ShahnejatBushehriAlluMehterovetal.2017, author = {Shahnejat-Bushehri, Sara and Allu, Annapurna Devi and Mehterov, Nikolay and Thirumalaikumar, Venkatesh P. and Alseekh, Saleh and Fernie, Alisdair R. and Mueller-Roeber, Bernd and Balazadeh, Salma}, title = {Arabidopsis NAC Transcription Factor JUNGBRUNNEN1 Exerts Conserved Control Over Gibberellin and Brassinosteroid Metabolism and Signaling Genes in Tomato}, series = {Frontiers in plant science}, volume = {8}, journal = {Frontiers in plant science}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-462X}, doi = {10.3389/fpls.2017.00214}, pages = {13}, year = {2017}, abstract = {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.}, language = {en} } @article{ShubchynskyyBonieckaSchweighoferetal.2017, author = {Shubchynskyy, Volodymyr and Boniecka, Justyna and Schweighofer, Alois and Simulis, Justinas and Kvederaviciute, Kotryna and Stumpe, Michael and Mauch, Felix and Balazadeh, Salma and M{\"u}ller-R{\"o}ber, Bernd and Boutrot, Freddy and Zipfel, Cyril and Meskiene, Irute}, title = {Protein phosphatase AP2C1 negatively regulates basal resistance and defense responses to Pseudomonas syringae}, series = {Journal of experimental botany}, volume = {68}, journal = {Journal of experimental botany}, number = {5}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0022-0957}, doi = {10.1093/jxb/erw485}, pages = {1169 -- 1183}, year = {2017}, abstract = {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.}, language = {en} } @misc{MachensBalazadehMuellerRoeberetal.2017, author = {Machens, Fabian and Balazadeh, Salma and M{\"u}ller-R{\"o}ber, Bernd and Messerschmidt, Katrin}, title = {Synthetic Promoters and Transcription Factors for Heterologous Protein Expression in Saccharomyces cerevisiae}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-403804}, pages = {11}, year = {2017}, abstract = {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.}, language = {en} } @article{MachensBalazadehMuellerRoeberetal.2017, author = {Machens, Fabian and Balazadeh, Salma and M{\"u}ller-R{\"o}ber, Bernd and Messerschmidt, Katrin}, title = {Synthetic Promoters and Transcription Factors for Heterologous Protein Expression in Saccharomyces cerevisiae}, series = {Frontiers in Bioengineering and Biotechnology}, volume = {5}, journal = {Frontiers in Bioengineering and Biotechnology}, publisher = {Frontiers}, address = {Lausanne}, issn = {2296-4185}, doi = {10.3389/fbioe.2017.00063}, pages = {1 -- 11}, year = {2017}, abstract = {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.}, language = {en} }