TY  - JOUR
A1  - Balazadeh, Salma
A1  - Kwasniewski, Miroslaw
A1  - Caldana, Camila
A1  - Mehrnia, Mohammad
A1  - Zanor, Maria Ines
A1  - Xue, Gang-Ping
A1  - Müller-Röber, Bernd
T1  - ORS1, an H2O2-Responsive NAC Transcription Factor, Controls Senescence in Arabidopsis thaliana
JF  - Molecular plant
N2  - We report here that ORS1, a previously uncharacterized member of the NAC transcription factor family, controls leaf senescence in Arabidopsis thaliana. Overexpression of ORS1 accelerates senescence in transgenic plants, whereas its inhibition delays it. Genes acting downstream of ORS1 were identified by global expression analysis using transgenic plants producing dexamethasone-inducible ORS1-GR fusion protein. Of the 42 up-regulated genes, 30 (similar to 70%) were previously shown to be up-regulated during age-dependent senescence. We also observed that 32 (similar to 76%) of the ORS1-dependent genes were induced by long-term (4 d), but not short-term (6 h) salinity stress (150 mM NaCl). Furthermore, expression of 16 and 24 genes, respectively, was induced after 1 and 5 h of treatment with hydrogen peroxide (H2O2), a reactive oxygen species known to accumulate during salinity stress. ORS1 itself was found to be rapidly and strongly induced by H2O2 treatment in both leaves and roots. Using in vitro binding site selection, we determined the preferred binding motif of ORS1 and found it to be present in half of the ORS1-dependent genes. ORS1 is a paralog of ORE1/ANAC092/AtNAC2, a previously reported regulator of leaf senescence. Phylogenetic footprinting revealed evolutionary conservation of the ORS1 and ORE1 promoter sequences in different Brassicaceae species, indicating strong positive selection acting on both genes. We conclude that ORS1, similarly to ORE1, triggers expression of senescence-associated genes through a regulatory network that may involve cross-talk with salt- and H2O2-dependent signaling pathways.
KW  - NAC transcription factor
KW  - leaf senescence
KW  - gene expression
KW  - gene regulatory network
KW  - hydrogen peroxide
Y1  - 2011
U6  - https://doi.org/10.1093/mp/ssq080
SN  - 1674-2052
VL  - 4
IS  - 2
SP  - 346
EP  - 360
PB  - Oxford Univ. Press
CY  - Oxford
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  -