Copper homeostasis influences the circadian clock in Arabidopsis.

Almost every aspect of plant physiology is influenced by diurnal and seasonal environmental cycles which suggests that biochemical oscillations must be a pervasive phenomenon in the underlying molecular organization. The circadian clock is entrained by light and temperature cycles, and controls a wide variety of endogenous processes that enable plants to anticipate the daily periodicity of environmental conditions. Several previous reports suggest a connection between copper (Cu) homeostasis and the circadian clock in different organisms other than plants. However, the nature of the Cu homeostasis influence on chronobiology remains elusive. Cytosolic Cu content could oscillate since Cu regulates its own transporters expression. We recently reported how the deregulation of Cu homeostasis in Arabidopsis transgenic plants affects the expression of two MYB transcription factors which are nuclear components of the circadian clock. In this addendum, we hypothesize the advantages that could be derived from the influence of metal homeostasis on plant circadian rhythms and their significance.