TY  - JOUR
A1  - Rauf, Mamoona
A1  - Arif, Muhammad
A1  - Dortay, Hakan
A1  - Matallana-Ramirez, Lilian P.
A1  - Waters, Mark T.
A1  - Nam, Hong Gil
A1  - Lim, Pyung-Ok
A1  - Müller-Röber, Bernd
A1  - Balazadeh, Salma
T1  - ORE1 balances leaf senescence against maintenance by antagonizing G2-like-mediated transcription
JF  - EMBO reports
N2  - Leaf senescence is a key physiological process in all plants. Its onset is tightly controlled by transcription factors, of which NAC factor ORE1 (ANAC092) is crucial in Arabidopsis thaliana. Enhanced expression of ORE1 triggers early senescence by controlling a downstream gene network that includes various senescence-associated genes. Here, we report that unexpectedly ORE1 interacts with the G2-like transcription factors GLK1 and GLK2, which are important for chloroplast development and maintenance, and thereby for leaf maintenance. ORE1 antagonizes GLK transcriptional activity, shifting the balance from chloroplast maintenance towards deterioration. Our finding identifies a new mechanism important for the control of senescence by ORE1.
KW  - transcription factor
KW  - senescence
KW  - chloroplast
KW  - protein-protein interaction
Y1  - 2013
U6  - https://doi.org/10.1038/embor.2013.24
SN  - 1469-221X
VL  - 14
IS  - 4
SP  - 382
EP  - 388
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Rauf, Mamoona
A1  - Arif, Muhammad
A1  - Fisahn, Joachim
A1  - Xue, Gang-Ping
A1  - Balazadeh, Salma
A1  - Müller-Röber, Bernd
T1  - NAC transcription factor speedy hyponastic growth regulates flooding-induced leaf movement in arabidopsis
JF  - The plant cell
N2  - In rosette plants, root flooding (waterlogging) triggers rapid upward (hyponastic) leaf movement representing an important architectural stress response that critically determines plant performance in natural habitats. The directional growth is based on localized longitudinal cell expansion at the lower (abaxial) side of the leaf petiole and involves the volatile phytohormone ethylene (ET). We report the existence of a transcriptional core unit underlying directional petiole growth in Arabidopsis thaliana, governed by the NAC transcription factor SPEEDY HYPONASTIC GROWTH (SHYG). Overexpression of SHYG in transgenic Arabidopsis thaliana enhances waterlogging-triggered hyponastic leaf movement and cell expansion in abaxial cells of the basal petiole region, while both responses are largely diminished in shyg knockout mutants. Expression of several EXPANSIN and XYLOGLUCAN ENDOTRANSGLYCOSYLASE/HYDROLASE genes encoding cell wall-loosening proteins was enhanced in SHYG overexpressors but lowered in shyg. We identified ACC OXIDASE5 (ACO5), encoding a key enzyme of ET biosynthesis, as a direct transcriptional output gene of SHYG and found a significantly reduced leaf movement in response to root flooding in aco5 T-DNA insertion mutants. Expression of SHYG in shoot tissue is triggered by root flooding and treatment with ET, constituting an intrinsic ET-SHYG-ACO5 activator loop for rapid petiole cell expansion upon waterlogging.
Y1  - 2013
U6  - https://doi.org/10.1105/tpc.113.117861
SN  - 1040-4651
SN  - 1532-298X
VL  - 25
IS  - 12
SP  - 4941
EP  - 4955
PB  - American Society of Plant Physiologists
CY  - Rockville
ER  -