TY - JOUR

T1 - Cytosolic phosphofructokinases are important for sugar homeostasis in leaves of Arabidopsis thaliana

AU - Perby, Laura Kathrine

AU - Richter, Simon

AU - Weber, Konrad

AU - Hieber, Alina Johanna

AU - Hess, Natalia

AU - Crocoll, Christoph

AU - Mogensen, Helle Kildal

AU - Pribil, Mathias

AU - Burow, Meike

AU - Nielsen, Tom Hamborg

AU - Mustroph, Angelika

N1 - © The Author(s) 2021. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

PY - 2022

Y1 - 2022

N2 - BACKGROUND AND AIMS: ATP-dependent phosphofructokinases (PFKs) catalyse phosphorylation of the carbon-1 position of fructose-6-phosphate, to form fructose-1,6-bisphosphate. In the cytosol, this is considered a key step in channelling carbon into glycolysis. Arabidopsis thaliana has seven genes encoding PFK isoforms, two chloroplastic and five cytosolic. This study focusses on the four major cytosolic isoforms of PFK in vegetative tissues of A. thaliana.METHODS: We have isolated homozygous knock-out individual mutants (pfk1, pfk3, pfk6, pfk7) and two double mutants (pfk1/7 and pfk3/6) and characterized their growth and metabolic phenotypes.KEY RESULTS: In contrast to single mutants and the double mutant pfk3/6 for the hypoxia-responsive isoforms, the double mutant pfk1/7 had reduced PFK activity and shows a clear visual and metabolic phenotype with reduced shoot growth, early flowering, and elevated hexose levels. This mutant also has an altered ratio of short/long aliphatic glucosinolates and an altered root-shoot distribution. Surprisingly, this mutant does not show any major changes in short-term carbon flux and in levels of hexose-phosphates.CONCLUSIONS: We conclude that the two isoforms PFK1 and PFK7 are important for sugar homeostasis in leaf metabolism and apparently source/sink relations in Arabidopsis, while PFK3 and PFK6 only play a minor role under normal growth conditions.

AB - BACKGROUND AND AIMS: ATP-dependent phosphofructokinases (PFKs) catalyse phosphorylation of the carbon-1 position of fructose-6-phosphate, to form fructose-1,6-bisphosphate. In the cytosol, this is considered a key step in channelling carbon into glycolysis. Arabidopsis thaliana has seven genes encoding PFK isoforms, two chloroplastic and five cytosolic. This study focusses on the four major cytosolic isoforms of PFK in vegetative tissues of A. thaliana.METHODS: We have isolated homozygous knock-out individual mutants (pfk1, pfk3, pfk6, pfk7) and two double mutants (pfk1/7 and pfk3/6) and characterized their growth and metabolic phenotypes.KEY RESULTS: In contrast to single mutants and the double mutant pfk3/6 for the hypoxia-responsive isoforms, the double mutant pfk1/7 had reduced PFK activity and shows a clear visual and metabolic phenotype with reduced shoot growth, early flowering, and elevated hexose levels. This mutant also has an altered ratio of short/long aliphatic glucosinolates and an altered root-shoot distribution. Surprisingly, this mutant does not show any major changes in short-term carbon flux and in levels of hexose-phosphates.CONCLUSIONS: We conclude that the two isoforms PFK1 and PFK7 are important for sugar homeostasis in leaf metabolism and apparently source/sink relations in Arabidopsis, while PFK3 and PFK6 only play a minor role under normal growth conditions.

U2 - 10.1093/aob/mcab122

DO - 10.1093/aob/mcab122

M3 - Journal article

C2 - 34549262

VL - 129

SP - 37

EP - 52

JO - Annals of Botany

JF - Annals of Botany

SN - 0305-7364

IS - 1

ER -