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Arabidopsis cytosolic alpha-glycan phosphorylase, PHS2, is important during carbohydrate imbalanced conditions.

Schopper, Simone LU ; Mühlenbock, P; Sörensson, Carolin LU ; Hellborg, Linda LU ; Lenman, M; Widell, Susanne LU ; Fettke, J and Andreasson, E (2015) In Plant Biology 17(1). p.74-80
Abstract
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... (More)
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 °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. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Plant Biology
volume
17
issue
1
pages
74 - 80
publisher
Wiley-Blackwell
external identifiers
  • pmid:24888726
  • wos:000347707900009
  • scopus:84923224911
ISSN
1438-8677
DOI
10.1111/plb.12190
language
English
LU publication?
yes
id
4c79d278-1910-4dff-85c6-5541d14d03ac (old id 4529379)
date added to LUP
2014-09-29 15:47:20
date last changed
2017-01-01 03:45:17
@article{4c79d278-1910-4dff-85c6-5541d14d03ac,
  abstract     = {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 °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.},
  author       = {Schopper, Simone and Mühlenbock, P and Sörensson, Carolin and Hellborg, Linda and Lenman, M and Widell, Susanne and Fettke, J and Andreasson, E},
  issn         = {1438-8677},
  language     = {eng},
  number       = {1},
  pages        = {74--80},
  publisher    = {Wiley-Blackwell},
  series       = {Plant Biology},
  title        = {Arabidopsis cytosolic alpha-glycan phosphorylase, PHS2, is important during carbohydrate imbalanced conditions.},
  url          = {http://dx.doi.org/10.1111/plb.12190},
  volume       = {17},
  year         = {2015},
}