TY  - THES
A1  - Siddiqui, Hamad
T1  - Isolation and functional characterization of novel NAC genes playing a crucial role in leaf senescence in Arabidopsis thaliana (L.) Heynh
Y1  - 2008
CY  - Potsdam
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  - Wu, Anhui
A1  - Allu, Annapurna Devi
A1  - Garapati, Prashanth
A1  - Siddiqui, Hamad
A1  - Dortay, Hakan
A1  - Zanor, Maria-Ines
A1  - Asensi-Fabado, Maria Amparo
A1  - Munne-Bosch, Sergi
A1  - Antonio, Carla
A1  - Tohge, Takayuki
A1  - Fernie, Alisdair R.
A1  - Kaufmann, Kerstin
A1  - Xue, Gang-Ping
A1  - Müller-Röber, Bernd
A1  - Balazadeh, Salma
T1  - Jungbrunnen1, a reactive oxygen species-responsive NAC transcription factor, regulates longevity in arabidopsis
JF  - The plant cell
N2  - The transition from juvenility through maturation to senescence is a complex process that involves the regulation of longevity. Here, we identify JUNGBRUNNEN1 (JUB1), a hydrogen peroxide (H2O2)-induced NAC transcription factor, as a central longevity regulator in Arabidopsis thaliana. JUB1 overexpression strongly delays senescence, dampens intracellular H2O2 levels, and enhances tolerance to various abiotic stresses, whereas in jub1-1 knockdown plants, precocious senescence and lowered abiotic stress tolerance are observed. A JUB1 binding site containing a RRYGCCGT core sequence is present in the promoter of DREB2A, which plays an important role in abiotic stress responses. JUB1 transactivates DREB2A expression in mesophyll cell protoplasts and transgenic plants and binds directly to the DREB2A promoter. Transcriptome profiling of JUB1 overexpressors revealed elevated expression of several reactive oxygen species-responsive genes, including heat shock protein and glutathione S-transferase genes, whose expression is further induced by H2O2 treatment. Metabolite profiling identified elevated Pro and trehalose levels in JUB1 overexpressors, in accordance with their enhanced abiotic stress tolerance. We suggest that JUB1 constitutes a central regulator of a finely tuned control system that modulates cellular H2O2 level and primes the plants for upcoming stress through a gene regulatory network that involves DREB2A.
Y1  - 2012
U6  - https://doi.org/10.1105/tpc.111.090894
SN  - 1040-4651
VL  - 24
IS  - 2
SP  - 482
EP  - 506
PB  - American Society of Plant Physiologists
CY  - Rockville
ER  -