TY  - JOUR
A1  - Schopper, S.
A1  - Muhlenbock, P.
A1  - Sorensson, C.
A1  - Hellborg, L.
A1  - Lenman, M.
A1  - Widell, S.
A1  - Fettke, Jörg
A1  - Andreasson, Erik
T1  - Arabidopsis cytosolic alpha-glycan phosphorylase, PHS2, is important during carbohydrate imbalanced conditions
JF  - Plant biology
N2  - Arabidopsis thaliana has two isoforms of alpha-glycan phosphorylase (EC 2.4.1.1), one residing in the plastid and the other in the cytosol. The cytosolic phosphorylase, PHS2, acts on soluble heteroglycans that constitute a part of the carbohydrate pool in a plant. This study aimed to define a physiological role for PHS2. Under standard growth conditions phs2 knock-out mutants do not show any clear growth phenotype, and we hypothesised that during low-light conditions where carbohydrate imbalance is perturbed, this enzyme is important. Soil-grown phs2 mutant plants developed leaf lesions when placed in very low light. Analysis of soluble heteroglycan (SHG) levels showed that the amount of glucose residues in SHG was higher in the phs2 mutant compared to wild-type plants. Furthermore, a standard senescence assay from soil-grown phs2 mutant plants showed that leaves senesced significantly faster in darkness than the wild-type leaves. We also found decreased hypocotyl extension in in vitro-grown phs2 mutant seedlings when grown for long time in darkness at 6 degrees C. We conclude that PHS2 activity is important in the adult stage during low-light conditions and senescence, as well as during prolonged seedling development when carbohydrate levels are unbalanced.
KW  - Lesion formation
KW  - low light stress conditions
KW  - phosphorylase
KW  - PHS2
KW  - senescence
KW  - soluble heteroglycans
Y1  - 2015
U6  - https://doi.org/10.1111/plb.12190
SN  - 1435-8603
SN  - 1438-8677
VL  - 17
IS  - 1
SP  - 74
EP  - 80
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Fettke, Jörg
A1  - Fernie, Alisdair R.
T1  - Intracellular and cell-to-apoplast compartmentation of carbohydrate metabolism
JF  - Trends in plant science
N2  - In most plants, carbohydrates represent the major energy store as well as providing the building blocks for essential structural polymers. Although the major pathways for carbohydrate biosynthesis, degradation, and transport are well characterized, several key steps have only recently been discovered. In addition, several novel minor metabolic routes have been uncovered in the past few years. Here we review current studies of plant carbohydrate metabolism detailing the expanding compendium of functionally characterized transport proteins as well as our deeper comprehension of more minor and conditionally activated metabolic pathways. We additionally explore the pertinent questions that will allow us to enhance our understanding of the response of both major and minor carbohydrate fluxes to changing cellular circumstances.
Y1  - 2015
U6  - https://doi.org/10.1016/j.tplants.2015.04.012
SN  - 1360-1385
VL  - 20
IS  - 8
SP  - 490
EP  - 497
PB  - Elsevier
CY  - London
ER  -