Yanovsky M J, Mazzella M A, Whitelam G C, Casal J J
IFEVA, Faculty of Agronomy, University of Buenos Aires, Argentina.
J Biol Rhythms. 2001 Dec;16(6):523-30. doi: 10.1177/074873001129002213.
The authors sought to investigate the role of phytochromes A and B (phyA and phyB) and cryptochromes 1 and 2 (cryl and cry2) in the synchronization of the leaf position rhythm in Arabidopsis thaliana. The seedlings were transferred from white light-dark cycles to free-running conditions with or without exposure to a light treatment during the final hours of the last dark period. The phase advance caused by a far-red light treatment was absent in the phyA mutant, deficient in the fhy1 and fhy3 mutants involved in phyA signaling, and normal in the cryl and cryl cry2 mutants. The phase shift caused by blue light was normal in the cry2 mutant; reduced in the phyA, cryl, phyA cry1, and cry1 cry2 mutants; and abolished in the phyA cryl cry2 triple mutant. The phase shift caused by red light was partially retained by the phyA phyB double mutant. The authors conclude that cryl and cry2 participate as photoreceptors in the blue light input to the clock but are not required for the phyA-mediated effects on the phase of the circadian rhythm of leaf position. The signaling proteins FHY1 and FHY3 are shared by phyA-mediated photomorphogenesis and phyA input to the clock.
作者试图研究光敏色素A和B（phyA和phyB）以及隐花色素1和2（cry1和cry2）在拟南芥叶片位置节律同步中的作用。在最后一个黑暗期的最后几个小时，将幼苗从白光-黑暗循环转移到自由运行条件下，有或没有进行光照处理。远红光处理引起的相位提前在phyA突变体中不存在，在参与phyA信号传导的fhy1和fhy3突变体中缺乏，而在cry1和cry1 cry2突变体中正常。蓝光引起的相移在cry2突变体中正常；在phyA、cry1、phyA cry1和cry1 cry2突变体中减少；在phyA cry1 cry2三重突变体中消除。红光引起的相移在phyA phyB双突变体中部分保留。作者得出结论，cry1和cry2作为光感受器参与了时钟的蓝光输入，但对于phyA介导的对叶片位置昼夜节律相位的影响不是必需的。信号蛋白FHY1和FHY3在phyA介导的光形态建成和phyA对时钟的输入中是共享的。
