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Constitutive expression of CIR1 ( RVE2 ) affects several circadian‐regulated processes and seed germination in Arabidopsis
Author(s) -
Zhang Xiangbo,
Chen Yanhui,
Wang ZhiYong,
Chen Zhangliang,
Gu Hongya,
Qu LiJia
Publication year - 2007
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/j.1365-313x.2007.03156.x
Subject(s) - circadian rhythm , circadian clock , biology , arabidopsis , microbiology and biotechnology , bacterial circadian rhythms , endogeny , period (music) , gene expression , photoperiodism , gene , genetics , botany , neuroscience , mutant , endocrinology , acoustics , physics
Summary Circadian clocks are endogenous auto‐regulatory mechanisms that allow organisms, from bacteria to humans, to advantageously time a wide range of activities within 24 h environmental cycles. Here we report the identification and characterization of an MYB‐related gene, designated Cir cadian 1 ( CIR1 ), that is involved in circadian regulation in Arabidopsis. Expression of CIR1 is transiently induced by light and oscillates with a circadian rhythm. The rhythmic expression of CIR1 is controlled by the central oscillator. Constitutive expression of CIR1 resulted in a shorter period length for the rhythms of four central oscillator components, and much lower amplitude for the rhythms of central oscillator components CCA1 and LHY . Furthermore, CIR1 over‐expression severely affected the circadian rhythms of its own RNA and those of the slave oscillator EPR1 and effector genes Lhcb and CAT3 . Plants that constitutively expressed CIR1 displayed delayed flowering, longer hypocotyls and reduced seed germination in the dark. These results suggest that CIR1 is possibly part of a regulatory feedback loop that controls a subset of the circadian outputs and modulates the central oscillator.