TY  - JOUR
A1  - Muntaha, Sidratul Nur
A1  - Li, Xiaoping
A1  - Compart, Julia
A1  - Apriyanto, Ardha
A1  - Fettke, Jörg
T1  - Carbon pathways during transitory starch degradation in Arabidopsis differentially affect the starch granule number and morphology in the dpe2/phs1 mutant background
JF  - Plant physiology and biochemistry : an official journal of the Federation of European Societies of Plant Physiology
N2  - The Arabidopsis knockout mutant lacking both the cytosolic disproportionating enzyme 2 (DPE2) and the plastidial phosphorylase (PHS1) had a dwarf-growth phenotype, a reduced and uneven distribution of starch within the plant rosettes, and a lower starch granule number per chloroplast under standard growth conditions. In contrast, a triple mutant impaired in starch degradation by its additional lack of the glucan, water dikinase (GWD) showed improved plant growth, a starch-excess phenotype, and a homogeneous starch distribution. Furthermore, the number of starch granules per chloroplast was increased and was similar to the wild type. We concluded that ongoing starch degradation is mainly responsible for the observed phenotype of dpe2/phs1. Next, we generated two further triple mutants lacking either the phosphoglucan, water dikinase (PWD), or the disproportionating enzyme 1 (DPE1) in the background of the double mutant. Analysis of the starch metabolism revealed that even minor ongoing starch degradation observed in dpe2/phs1/pwd maintained the double mutant phenotype. In contrast, an additional blockage in the glucose pathway of starch breakdown, as in dpe2/phs1/ dpe1, resulted in a nearly starch-free phenotype and massive chloroplast degradation. The characterized mutants were discussed in the context of starch granule formation.
KW  - Starch granules
KW  - Starch metabolism
KW  - Starch granule number per
KW  - chloroplast
KW  - Starch morphology
KW  - LCSM
KW  - Arabidopsis thaliana
Y1  - 2022
U6  - https://doi.org/10.1016/j.plaphy.2022.03.033
SN  - 0981-9428
SN  - 1873-2690
VL  - 180
SP  - 35
EP  - 41
PB  - Elsevier
CY  - Paris
ER  - 
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  -