title: Salt-triggered expression of the ANAC092-dependent senescence regulon in Arabidopsis thaliana.
abstract: The NAC domain transcription factor ANAC092 plays a central role in leaf senescence in Arabidopsis thaliana. We recently identified 170 genes whose expression increases upon activation of ANAC092 in a chemically (estradiol) controlled experimental set-up, 78 of which are known senescence-associated genes (SAGs). In accordance with the well-known phenomenon that salt stress promotes early leaf senescence in many plant species, we previously observed salt stress-enhanced expression of many SAGs of the ANAC092 regulon. Global expression profiling now revealed that 36 genes, representing 46% of all ANAC092 downstream SAGs, are induced by long-term (4 days) salt stress in shoots of Arabidopsis, whereas short-term stress (6 hours) only slightly affects gene expression. Expression analysis also showed that 14 of the 36 genes are induced by hydrogen peroxide (H2O2) treatment. Additionally, 15 senescence-associated NAC genes (senNACs), including ANAC092, respond to H2O2 exposure. Our data support the model that salt-triggered senescence is at least partly mediated through the ANAC092 gene regulatory network. Other senNACs most likely contribute to the coordination of this process, potentially in concert with H2O2-mediated signaling.
authors.affiliation: University of Potsdam, Institute of Biochemistry and Biology, Potsdam-Golm, Germany.
authors.forename: Salma
authors.initials: S
authors.lastname: Balazadeh
authors.forename: Anhui
authors.initials: A
authors.lastname: Wu
authors.forename: Bernd
authors.initials: B
authors.lastname: Mueller-Roeber
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