TY  - JOUR
A1  - Oliver, Sandra N.
A1  - Lunn, John Edward
A1  - Urbanczyk-Wochniak, Ewa
A1  - Lytovchenko, Anna
A1  - van Dongen, Joost T.
A1  - Faix, Benjamin
A1  - Schmälzlin, Elmar
A1  - Fernie, Alisdair R.
A1  - Schmäelzlin, E.
A1  - Geigenberger, Peter
T1  - Decreased expression of cytosolic pyruvate kinase in potato tubers leads to a decline in pyruvate resulting in an in vivo repression of the alternative oxidase
N2  - The aim of this work was to investigate the effect of decreased cytosolic pyruvate kinase (PKc) on potato (Solanum tuberosum) tuber metabolism. Transgenic potato plants with strongly reduced levels of PKc were generated by RNA interference gene silencing under the control of a tuber-specific promoter. Metabolite profiling showed that decreased PKc activity led to a decrease in the levels of pyruvate and some other organic acids involved in the tricarboxylic acid cycle. Flux analysis showed that this was accompanied by changes in carbon partitioning, with carbon flux being diverted from glycolysis toward starch synthesis. However, this metabolic shift was relatively small and hence did not result in enhanced starch levels in the tubers. Although total respiration rates and the ATP to ADP ratio were largely unchanged, transgenic tubers showed a strong decrease in the levels of alternative oxidase (AOX) protein and a corresponding decrease in the capacity of the alternative pathway of respiration. External feeding of pyruvate to tuber tissue or isolated mitochondria resulted in activation of the AOX pathway, both in the wild type and the PKc transgenic lines, providing direct evidence for the regulation of AOX by changes in pyruvate levels. Overall, these results provide evidence for a crucial role of PKc in the regulation of pyruvate levels as well as the level of the AOX in heterotrophic plant tissue, and furthermore reveal that these parameters are interlinked in vivo.
Y1  - 2008
UR  - http://www.plantphysiol.org/content/148/3/1640.full
U6  - https://doi.org/10.1104/pp.108.126516
ER  - 
TY  - JOUR
A1  - Eich, Susanne
A1  - Schmälzlin, Elmar
A1  - Löhmannsröben, Hans-Gerd
T1  - Distributed fiber optical sensing of Oxygen with optical time domain reflectometry
JF  - Sensors
N2  - In many biological and environmental applications spatially resolved sensing of molecular oxygen is desirable. A powerful tool for distributed measurements is optical time domain reflectometry (OTDR) which is often used in the field of telecommunications. We combine this technique with a novel optical oxygen sensor dye, triangular-[4] phenylene (TP), immobilized in a polymer matrix. The TP luminescence decay time is 86 ns. The short decay time of the sensor dye is suitable to achieve a spatial resolution of some meters. In this paper we present the development and characterization of a reflectometer in the UV range of the electromagnetic spectrum as well as optical oxygen sensing with different fiber arrangements.
KW  - OTDR
KW  - optical sensing
KW  - molecular oxygen
KW  - triangular-[4] phenylene
Y1  - 2013
U6  - https://doi.org/10.3390/s130607170
SN  - 1424-8220
VL  - 13
IS  - 6
SP  - 7170
EP  - 7183
PB  - MDPI
CY  - Basel
ER  -