Johnson C H, Knight M R, Kondo T, Masson P, Sedbrook J, Haley A, Trewavas A
Department of Biology, Vanderbilt University, Nashville, TN 37235, USA.
Science. 1995 Sep 29;269(5232):1863-5. doi: 10.1126/science.7569925.
Tobacco and Arabidopsis plants, expressing a transgene for the calcium-sensitive luminescent protein apoaequorin, revealed circadian oscillations in free cytosolic calcium that can be phase-shifted by light-dark signals. When apoaequorin was targeted to the chloroplast, circadian chloroplast calcium rhythms were likewise observed after transfer of the seedlings to constant darkness. Circadian oscillations in free calcium concentrations can be expected to control many calcium-dependent enzymes and processes accounting for circadian outputs. Regulation of calcium flux is therefore fundamental to the organization of circadian systems.
烟草和拟南芥植物表达了对钙敏感的发光蛋白脱辅基水母发光蛋白的转基因，揭示了游离胞质钙的昼夜节律振荡，这种振荡可被明暗信号进行相位调节。当脱辅基水母发光蛋白靶向叶绿体时，在将幼苗转移到持续黑暗环境后，同样观察到了叶绿体钙的昼夜节律。游离钙浓度的昼夜节律振荡有望控制许多钙依赖性酶和导致昼夜输出的过程。因此，钙通量的调节对于昼夜节律系统的组织至关重要。
