In Arabidopsis, the concentration of intracellular calcium fluctuates in a daily cycle, above and beyond other responses to signaling inputs. Tang et al. have now analyzed the interactions between intracellular and extracellular calcium concentrations, and various signaling components in between, to arrive at a complex view of calcium physiology in the plant. Not simply a passive reflection of external calcium status, the calcium levels within a resting cell are actively monitored and managed.
R.-H. Tang, S. Han, H. Zheng, C. W. Cook, C. S. Choi, T. E. Woerner, R. B. Jackson, Z.-M. Pei, Coupling diurnal cytosolic Ca2+ oscillations to the CAS-IP3 pathway in Arabidopsis. Science 315, 1423-1426 (2007). [Abstract] [Full Text]