期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1999
卷号：96
期号：20
页码：11659-11663
DOI：10.1073/pnas.96.20.11659
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Circadian biological clocks control many biological events, but the pathways by which these events are controlled are largely unknown. Based on a model suggesting that cytosolic-free calcium levels control the expression of the Lhcb gene in plants, we tested whether the circadian oscillation of free calcium is responsible for driving the rhythm of Lhcb expression. We found that these rhythms free-run with different periods in tobacco seedlings in constant conditions. Moreover, robust oscillations of Lhcb promoter activity continued in undifferentiated tobacco calli in the absence of Ca2+ oscillations. Therefore, these two circadian rhythms are not linked hierarchically. These data provide evidence for separate circadian pacemakers controlling molecular events in plants.
