@misc{SchippersNguyenLuetal.2012, author = {Schippers, Jos H. M. and Nguyen, Hung M. and Lu, Dandan and Schmidt, Romy and M{\"u}ller-R{\"o}ber, Bernd}, title = {ROS homeostasis during development: an evolutionary conserved strategy}, series = {Cellular and molecular life sciences}, volume = {69}, journal = {Cellular and molecular life sciences}, number = {19}, publisher = {Springer}, address = {Basel}, issn = {1420-682X}, doi = {10.1007/s00018-012-1092-4}, pages = {3245 -- 3257}, year = {2012}, abstract = {The balance between cellular proliferation and differentiation is a key aspect of development in multicellular organisms. Recent studies on Arabidopsis roots revealed distinct roles for different reactive oxygen species (ROS) in these processes. Modulation of the balance between ROS in proliferating cells and elongating cells is controlled at least in part at the transcriptional level. The effect of ROS on proliferation and differentiation is not specific for plants but appears to be conserved between prokaryotic and eukaryotic life forms. The ways in which ROS is received and how it affects cellular functioning is discussed from an evolutionary point of view. The different redox-sensing mechanisms that evolved ultimately result in the activation of gene regulatory networks that control cellular fate and decision-making. This review highlights the potential common origin of ROS sensing, indicating that organisms evolved similar strategies for utilizing ROS during development, and discusses ROS as an ancient universal developmental regulator.}, language = {en} } @article{SchmidtSchippersWelkeretal.2012, author = {Schmidt, Romy and Schippers, Jos H. M. and Welker, Annelie and Mieulet, Delphine and Guiderdoni, Emmanuel and M{\"u}ller-R{\"o}ber, Bernd}, title = {Transcription factor OsHsfC1b regulates salt tolerance and development in Oryza sativa ssp japonica}, series = {AoB PLANTS}, journal = {AoB PLANTS}, number = {3}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {2041-2851}, doi = {10.1093/aobpla/pls011}, pages = {17}, year = {2012}, abstract = {Background and aims Salt stress leads to attenuated growth and productivity in rice. Transcription factors like heat shock factors (HSFs) represent central regulators of stress adaptation. Heat shock factors of the classes A and B are well established as regulators of thermal and non-thermal stress responses in plants; however, the role of class C HSFs is unknown. Here we characterized the function of the OsHsfC1b (Os01g53220) transcription factor from rice. Methodology We analysed the expression of OsHsfC1b in the rice japonica cultivars Dongjin and Nipponbare exposed to salt stress as well as after mannitol, abscisic acid (ABA) and H2O2 treatment. For functional characterization of OsHsfC1b, we analysed the physiological response of a T-DNA insertion line (hsfc1b) and two artificial micro-RNA (amiRNA) knock-down lines to salt, mannitol and ABA treatment. In addition, we quantified the expression of small Heat Shock Protein (sHSP) genes and those related to signalling and ion homeostasis by quantitative real-time polymerase chain reaction in roots exposed to salt. The subcellular localization of OsHsfC1b protein fused to green fluorescent protein (GFP) was determined in Arabidopsis mesophyll cell protoplasts. Principal results Expression of OsHsfC1b was induced by salt, mannitol and ABA, but not by H2O2. Impaired function of OsHsfC1b in the hsfc1b mutant and the amiRNA lines led to decreased salt and osmotic stress tolerance, increased sensitivity to ABA, and temporal misregulation of salt-responsive genes involved in signalling and ion homeostasis. Furthermore, sHSP genes showed enhanced expression in knock-down plants under salt stress. We observed retarded growth of hsfc1b and knock-down lines in comparison with control plants under non-stress conditions. Transient expression of OsHsfC1b fused to GFP in protoplasts revealed nuclear localization of the transcription factor. Conclusions OsHsfC1b plays a role in ABA-mediated salt stress tolerance in rice. Furthermore, OsHsfC1b is involved in the response to osmotic stress and is required for plant growth under non-stress conditions.}, language = {en} } @article{SchmidtMieuletHubbertenetal.2013, author = {Schmidt, Romy and Mieulet, Delphine and Hubberten, Hans-Michael and Obata, Toshihiro and H{\"o}fgen, Rainer and Fernie, Alisdair R. and Fisahn, Joachim and Segundo, Blanca San and Guiderdoni, Emmanuel and Schippers, Jos H. M. and M{\"u}ller-R{\"o}ber, Bernd}, title = {Salt-responsive ERF1 regulates reactive oxygen species-dependent signaling during the initial response to salt stress in rice}, series = {The plant cell}, volume = {25}, journal = {The plant cell}, number = {6}, publisher = {American Society of Plant Physiologists}, address = {Rockville}, issn = {1040-4651}, doi = {10.1105/tpc.113.113068}, pages = {2115 -- 2131}, year = {2013}, abstract = {Early detection of salt stress is vital for plant survival and growth. Still, the molecular processes controlling early salt stress perception and signaling are not fully understood. Here, we identified SALT-RESPONSIVE ERF1 (SERF1), a rice (Oryza sativa) transcription factor (TF) gene that shows a root-specific induction upon salt and hydrogen peroxide (H2O2) treatment. Loss of SERF1 impairs the salt-inducible expression of genes encoding members of a mitogen-activated protein kinase (MAPK) cascade and salt tolerance-mediating TFs. Furthermore, we show that SERF1-dependent genes are H2O2 responsive and demonstrate that SERF1 binds to the promoters of MAPK KINASE KINASE6 (MAP3K6), MAPK5, DEHYDRATION-RESPONSIVE ELEMENT BINDING2A (DREB2A), and ZINC FINGER PROTEIN179 (ZFP179) in vitro and in vivo. SERF1 also directly induces its own gene expression. In addition, SERF1 is a phosphorylation target of MAPK5, resulting in enhanced transcriptional activity of SERF1 toward its direct target genes. In agreement, plants deficient for SERF1 are more sensitive to salt stress compared with the wild type, while constitutive overexpression of SERF1 improves salinity tolerance. We propose that SERF1 amplifies the reactive oxygen species-activated MAPK cascade signal during the initial phase of salt stress and translates the salt-induced signal into an appropriate expressional response resulting in salt tolerance.}, language = {en} } @article{SchmidtSchippersMieuletetal.2013, author = {Schmidt, Romy and Schippers, Jos H. M. and Mieulet, Delphine and Obata, Toshihiro and Fernie, Alisdair R. and Guiderdoni, Emmanuel and M{\"u}ller-R{\"o}ber, Bernd}, title = {Multipass, a rice R2R3-type MYB transcription factor, regulates adaptive growth by integrating multiple hormonal pathways}, series = {The plant journal}, volume = {76}, journal = {The plant journal}, number = {2}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0960-7412}, doi = {10.1111/tpj.12286}, pages = {258 -- 273}, year = {2013}, abstract = {Growth regulation is an important aspect of plant adaptation during environmental perturbations. Here, the role of MULTIPASS (OsMPS), an R2R3-type MYB transcription factor of rice, was explored. OsMPS is induced by salt stress and expressed in vegetative and reproductive tissues. Over-expression of OsMPS reduces growth under non-stress conditions, while knockdown plants display increased biomass. OsMPS expression is induced by abscisic acid and cytokinin, but is repressed by auxin, gibberellin and brassinolide. Growth retardation caused by OsMPS over-expression is partially restored by auxin application. Expression profiling revealed that OsMPS negatively regulates the expression of EXPANSIN (EXP) and cell-wall biosynthesis as well as phytohormone signaling genes. Furthermore, the expression of OsMPS-dependent genes is regulated by auxin, cytokinin and abscisic acid. Moreover, we show that OsMPS is a direct upstream regulator of OsEXPA4, OsEXPA8, OsEXPB2, OsEXPB3, OsEXPB6 and the endoglucanase genes OsGLU5 and OsGLU14. The multiple responses of OsMPS and its target genes to various hormones suggest an integrative function of OsMPS in the cross-talk between phytohormones and the environment to regulate adaptive growth.}, language = {en} } @article{SchmidtSchippersMieuletetal.2014, author = {Schmidt, Romy and Schippers, Jos H. M. and Mieulet, Delphine and Watanabe, Mutsumi and Hoefgen, Rainer and Guiderdoni, Emmanuel and M{\"u}ller-R{\"o}ber, Bernd}, title = {Salt-Rresponsive ERF1 is a negative regulator of grain filling and gibberellin-mediated seedling establishment in rice}, series = {Molecular plant}, volume = {7}, journal = {Molecular plant}, number = {2}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {1674-2052}, doi = {10.1093/mp/sst131}, pages = {404 -- 421}, year = {2014}, abstract = {Grain quality is an important agricultural trait that is mainly determined by grain size and composition. Here, we characterize the role of the rice transcription factor (TF) SALT-RESPONSIVE ERF1 (SERF1) during grain development. Through genome-wide expression profiling and chromatin immunoprecipitation, we found that SERF1 directly regulates RICE PROLAMIN-BOX BINDING FACTOR (RPBF), a TF that functions as a positive regulator of grain filling. Loss of SERF1 enhances RPBF expression resulting in larger grains with increased starch content, while SERF1 overexpression represses RPBF resulting in smaller grains. Consistently, during grain filling, starch biosynthesis genes such as GRANULE-BOUND STARCH SYNTHASEI (GBSSI), STARCH SYNTHASEI (SSI), SSIIIa, and ADP-GLUCOSE PYROPHOSPHORYLASE LARGE SUBUNIT2 (AGPL2) are up-regulated in SERF1 knockout grains. Moreover, SERF1 is a direct upstream regulator of GBSSI. In addition, SERF1 negatively regulates germination by controlling RPBF expression, which mediates the gibberellic acid (GA)-induced expression of RICE AMYLASE1A (RAmy1A). Loss of SERF1 results in more rapid seedling establishment, while SERF1 overexpression has the opposite effect. Our study reveals that SERF1 represents a negative regulator of grain filling and seedling establishment by timing the expression of RPBF.}, language = {en} }