Relationship between delayed luminescence emission and mitochondrial status in Saccharomyces cerevisiae

Delayed luminescence (DL) is gradually used in various detection of biological systems as a rapid detection technique, however, its biological mechanism was still not clear. In this study, a new model of DL detection system for liquid biological samples is established to investigate the DL emission of Saccharomyces cerevisiae cells cultured in different glucose concentrations. We analyzed the relationship between the DL emission and cell growth, cell vitality, mitochondrial morphology, mitochondrial DNA (mtDNA) copy number, adenosine triphosphate (ATP), oxygen consumption rate (OCR), as well as mitochondria membrane potential (MMP) in S. cerevisiae cells cultured with 0.01, 0.05, 0.15, 3, 10 and 20 g/L glucose respectively. It was found that the DL emission had strong correlation with mitochondrial morphology, OCR, and MMP. The results suggested that DL is an indicator of mitochondria status under different glucose supply conditions, and may be an effective method to detect mitochondrial metabolism related disorders.

Study on the characteristic curve of laser-induced delayed luminescence in leaves of Scindapsus

At room temperature, we studied the delayed luminescence characteristic curves of the leaves of Scindapsus in darkroom and continuously irradiate at different wavelengths. The results show that the decay of stimulated emission photons induced by pulsed laser has a typical hyperbolic trend with the delay time, and the goodness of fitted curve can reach 99.9%. The initial photon intensity I (0) and decay time τ are closely related to the environment and physiological activities of plants. In the dark room, it was found that the initial intensity and decay time of the delayed luminescence curve for picked leaves decreased, while the potted leaves remained almost unchanged. The characteristic curve of laser-induced delayed luminescence accurately reflected the process and degree of plant wilting. For continuously irradiated by the laser wavelength of 520 nm and 400 nm, respectively, the change in curve parameters reflects the selective absorption of different light wavelengths. Compare the condition with having light and without, the metabolites of photosynthesis and respiration are different in plants, which leads to greatly changes in decay time. The characteristic curve of laser-induced delayed luminescence can be used as an important parameter to measure the physiological state of plants.

Damming a Molecular Energy Reservoir: Ion-regulated Electronic Energy Shuttling in a [2]Rotaxane

Bidirectional electronic energy shuttling is shown to occur between the molecular ring and axle components of a rotaxane. The engineered energetic and kinetic parameters give rise to long-lived, delayed luminescence. Perturbation of the quasi-isoenergetic ring and stopper chromophore excited-state energy levels upon cation binding influences the energy shuttling process, and hence luminescence read-out, representing a new potential mechanism in luminescent molecular chemosensor development

Damming a Molecular Energy Reservoir: Ion-regulated Electronic Energy Shuttling in a [2]Rotaxane

Bidirectional electronic energy shuttling is shown to occur between the molecular ring and axle components of a rotaxane. The engineered energetic and kinetic parameters give rise to long-lived, delayed luminescence. Perturbation of the quasi-isoenergetic ring and stopper chromophore excited-state energy levels upon cation binding influences the energy shuttling process, and hence luminescence read-out, representing a new potential mechanism in luminescent molecular chemosensor development

Delayed luminescence of seeds: are shining seeds viable?

Delayed luminescence (DL) has been widely studied for its applications in developmental biology and describes a phenomenon whereby biological materials radiate for a relatively long time (seconds and more) after illumination. Researchers have postulated that DL is potentially useful for determining the physiological status of biological materials, including crop seeds. Until recently this claim only remained within academia and there have been no known reports for the advancement of its use in seed testing and genebank management. This article examines the gaps in knowledge for adopting DL for seed testing by reviewing the history of DL applications in analytical studies of crop seeds and the incompletely understood mechanisms within seeds for displaying DL. We identified a need for more experimental data to validate the DL mechanisms in seeds before the procedure can be used for seed testing.