TY  - JOUR
A1  - Ast, Cindy
A1  - Schmälzlin, Elmar
A1  - Löhmannsröben, Hans-Gerd
A1  - van Dongen, Joost T.
T1  - Optical oxygen micro- and nanosensors for plant applications
JF  - Sensors
N2  - Pioneered by Clark's microelectrode more than half a century ago, there has been substantial interest in developing new, miniaturized optical methods to detect molecular oxygen inside cells. While extensively used for animal tissue measurements, applications of intracellular optical oxygen biosensors are still scarce in plant science. A critical aspect is the strong autofluorescence of the green plant tissue that interferes with optical signals of commonly used oxygen probes. A recently developed dual-frequency phase modulation technique can overcome this limitation, offering new perspectives for plant research. This review gives an overview on the latest optical sensing techniques and methods based on phosphorescence quenching in diverse tissues and discusses the potential pitfalls for applications in plants. The most promising oxygen sensitive probes are reviewed plus different oxygen sensing structures ranging from micro-optodes to soluble nanoparticles. Moreover, the applicability of using heterologously expressed oxygen binding proteins and fluorescent proteins to determine changes in the cellular oxygen concentration are discussed as potential non-invasive cellular oxygen reporters.
KW  - oxygen sensor
KW  - biosensors
KW  - microsensors
KW  - nanosensors
KW  - endogenous sensor proteins
KW  - dual-frequency phase-modulation
KW  - phosphorescence quenching
KW  - plant science
Y1  - 2012
U6  - https://doi.org/10.3390/s120607015
SN  - 1424-8220
VL  - 12
IS  - 6
SP  - 7015
EP  - 7032
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Paparelli, Eleonora
A1  - Gonzali, Silvia
A1  - Parlanti, Sandro
A1  - Novi, Giacomo
A1  - Giorgi, Federico M.
A1  - Licausi, Francesco
A1  - Kosmacz, Monika
A1  - Feil, Regina
A1  - Lunn, John Edward
A1  - Brust, Henrike
A1  - van Dongen, Joost T.
A1  - Steup, Martin
A1  - Perata, Pierdomenico
T1  - Misexpression of a chloroplast aspartyl protease leads to severe growth defects and alters carbohydrate metabolism in arabidopsis
JF  - Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants
N2  - The crucial role of carbohydrate in plant growth and morphogenesis is widely recognized. In this study, we describe the characterization of nana, a dwarf Arabidopsis (Arabidopsis thaliana) mutant impaired in carbohydrate metabolism. We show that the nana dwarf phenotype was accompanied by altered leaf morphology and a delayed flowering time. Our genetic and molecular data indicate that the mutation in nana is due to a transfer DNA insertion in the promoter region of a gene encoding a chloroplast-located aspartyl protease that alters its pattern of expression. Overexpression of the gene (oxNANA) phenocopies the mutation. Both nana and oxNANA display alterations in carbohydrate content, and the extent of these changes varies depending on growth light intensity. In particular, in low light, soluble sugar levels are lower and do not show the daily fluctuations observed in wild-type plants. Moreover, nana and oxNANA are defective in the expression of some genes implicated in sugar metabolism and photosynthetic light harvesting. Interestingly, some chloroplast-encoded genes as well as genes whose products seem to be involved in retrograde signaling appear to be down-regulated. These findings suggest that the NANA aspartic protease has an important regulatory function in chloroplasts that not only influences photosynthetic carbon metabolism but also plastid and nuclear gene expression.
Y1  - 2012
U6  - https://doi.org/10.1104/pp.112.204016
SN  - 0032-0889
VL  - 160
IS  - 3
SP  - 1237
EP  - 1250
PB  - American Society of Plant Physiologists
CY  - Rockville
ER  -