Circadian redox signaling in plant immunity and abiotic stress.
CONCLUSIONS
Plant crops are critically important to provide quality food and bio-energy to sustain a growing human population. Circadian clocks have been shown to deliver an adaptive advantage to plants, vastly increasing biomass production by efficient anticipation to the solar cycle. Plant stress, on the other hand, whether biotic or abiotic, prevents crops from reaching maximum productivity.


BACKGROUND
Stress is associated with fluctuations in cellular redox and increased phytohormone signaling. Recently, direct links between circadian timekeeping, redox fluctuations, and hormone signaling have been identified. A direct implication is that circadian control of cellular redox homeostasis influences how plants negate stress to ensure growth and reproduction.


RESULTS
Complex cellular biochemistry leads from perception of stress via hormone signals and formation of reactive oxygen intermediates to a physiological response. Circadian clocks and metabolic pathways intertwine to form a confusing biochemical labyrinth. Here, we aim to find order in this complex matter by reviewing current advances in our understanding of the interface between these networks.


CONCLUSIONS
Although the link is now clearly defined, at present a key question remains as to what extent the circadian clock modulates redox, and vice versa. Furthermore, the mechanistic basis by which the circadian clock gates redox- and hormone-mediated stress responses remains largely elusive.
1 Institute for Molecular Plant Sciences, University of Edinburgh , Edinburgh, United Kingdom .
Steven H
SH
Spoel
Gerben
G
van Ooijen
D002940:Circadian Rhythm / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D010084:Oxidation-Reduction; D010937:Plant Growth Regulators / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D057865:Plant Immunity / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D010944:Plants / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D013312:Stress, Physiological / Q000235:genetics / Q000276:immunology / Q000502:physiology*
D010937:Plant Growth Regulators