Interactions between circadian clocks and photosynthesis for the temporal and spatial coordination of metabolism

Abstract

All plant productivity, including the food that we eat, arises from the capture of solar energy by plants. At most latitudes sunlight is available for only part of the 24 h day due to the rotation of the planet. This rhythmic and predictable alteration in the environment has driven the evolution of the circadian clock, which has an extremely pervasive influence upon plant molecular biology, physiology and phenology. A number of recent studies have demonstrated that the circadian clock is integrated very closely with photosynthesis and its metabolic products. We consider the coupling of the circadian oscillator with carbohydrate biochemistry and the connections between the nuclear-encoded circadian clock and processes within chloroplasts. We describe how this might provide adaptations to optimize plant performance in an environment that varies both predictably upon a daily and seasonal basis, and unpredictably due to the weather.

Thermal plasticity of the circadian clock is under nuclear and cytoplasmic control in wild barley

“…Nevertheless, the nature of the signal and sensitivity to circadian rhythm are unknown. Of note, it has been suggested that circadian regulation of photosynthesis within chloroplasts causes modulation of a retrograde signal that alters nuclear mRNA (Dodd et al, ), including alternative splicing of nuclear‐encoded transcripts SR protein (a regulator of RNA splicing) and other splicing factors (Petrillo et al, ). However, to the best of our knowledge there are no reports of circadian clock plasticity sensors or initiators within the chloroplast.…”

“…Nevertheless, the nature of the signal and sensitivity to circadian rhythm are unknown. Of note, it has been suggested that circadian regulation of photosynthesis within chloroplasts causes modulation of a retrograde signal that alters nuclear mRNA (Dodd et al, 2015), including alternative splicing of nuclear-encoded transcripts SR protein (a regulator of RNA splicing) and other splicing factors (Petrillo et al, 2014). and rpoC2) and nuclear sigma factors (sig 1-6); coordinated rates of molecular evolution between the chloroplast and nuclear encoded genes were observed, at least in Geraniaceae (Zhang, Ruhlman, Sabir, Blazier, & Jansen, 2015).…”

The Plant Circadian Clock: From a Simple Timekeeper to a Complex Developmental Manager

“…In summary, carbohydrates can influence the biological timekeeper by regulating the transcriptome and the period or the phase of the clock under different growing conditions. Considering that sugar could contribute to the fine-tuning of the circadian clock and that flowering time in long days is tightly controlled by the endogenous oscillator, it has been hypothesized that carbohydrates could also have a role in modulating the sensitivity to photoperiodic detection (Dodd et al 2015).…”

Transcriptional control of photosynthetic capacity: conservation and divergence from Arabidopsis to rice

“…Most relevant is that the UVR8-COP1 interaction leads to the expression and stabilization of HY5 and HYH transcription factors (Rizzini et al, 2011;Jenkins, 2014). Also of note is that ZTL family photoreceptors control the degradation of the key clock gene TOC1 (Somers et al, 2000;Schultz et al, 2001), and thus ZTL photoreceptors play a role in the regulation of the circadian clock, which is intricately linked to the control of photosynthesis gene expression (Dodd et al, 2015).…”