Endogenous oscillations in pathways of energy transduction as related to circadian rhythmicity and photoperiodic control

Metabolic control of transcriptional-translational control loops (TTCL) by circadian oscillations in the redox- and phosphorylation state of cells

“…Evolving life was paralleled by the corresponding evolution of tropospheric O 2 /CO 2 composition and feedback of oxygen on life processes via reactive oxygen (Paietta 1982) and reactive nitrogen species; in turn these molecules, acting as signalling molecules, became crucial for the control of development of prokaryotic and eukaryotic living systems. Adaptation to the seasonal variation in day length resulted in photoperiodic control of development with a circadian rhythm in energy conservation and transformation to optimise energy-harvesting by photosynthesis (Wagner et al 1975;Foyer & Noctor 2003). Photosynthesis, on the other hand, acts as a metabolic regulator via redox signals (Zeilstra-Ryalls et al 1998;Oh & Kaplan 2000;Pfannschmidt et al 2001;Sherameti et al 2002;Pfannschmidt 2003;Buchanan & Balmer 2005) in addition to specific photoreceptor systems like phytochromes and cryptochromes.…”

“…This network produces a circadian rhythm in adenylate energy charge and redox state (NADP/NADPH 2 ). The nucleotide ratios themselves could act as rate effectors in metabolic pathways and in compartmental feedback and thus fulfil the requirements of precise temperature-compensated time-keeping (Frosch & Wagner 1973;Wagner et al 1975Wagner et al , 1993Wagner et al , 1998.…”

“…Considering metabolic control of timing in photoperiodism (Wagner & Cumming 1970;Wagner et al 1975), it must be remembered that evolution from prokaryotic to eukaryotic organisms was paralleled by a corresponding evolution in energy metabolism. From primary fermentation, energy conservation progressed to anaerobic photosynthesis and then to carbon dioxide fixation with acceptance of electrons by water and evolution of oxygen (Bekker et al 2004).…”

“…Following Bü nning's (1942) and Hendricks' (1963) early concepts on metabolic control of timing in photoperiodism, C. rubrum has been used to analyse energy metabolism, demonstrating a circadian rhythm in redox state and energy charge as two macroparameters timing photoperiodic behaviour (Wagner et al 1975). Recently, C. rubrum was also used in molecular studies on signal transduction in photoperiodic flower induction (Walczysko et al 2000;Albrechtová 2004;Veit et al 2004).…”

An ultradian clock shapes genome expression in yeast

“…Although there is presently no evidence for regulation of this sort in the ultradian domain (minutes to hours), wideranging metabolic oscillations have in fact been described in circadian studies of plants and animals. For example, circadian changes in cellular redox were described in plants several decades ago (16), and robust 24-hr oscillations of reduced glutathione are commonly observed in mammalian cells (17). It may be significant that restricted feeding, which acutely alters reduced glutathione levels, resets the phases of circadian clocks in many mammalian tissues (17)(18)(19).…”