Arabidopsis FHY3 specifically gates phytochrome signaling to the circadian clock
Arabidopsis FHY3 specifically gates phytochrome signaling to the circadian clock
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DOI：
10.1105/tpc.105.037358
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发表时间：
2006-10-01
期刊：
影响因子：
11.6
通讯作者：
Devlin, Paul F.
中科院分区：
文献类型：
--
作者：
Allen, Trudie;Koustenis, Athanasios;Devlin, Paul F.
光信号的昼夜节律门控将对光的最大反应的时间限制在一天中的特定时间。拟南芥的fhy3(远红细长下胚轴3)突变体参与了一组光感受器对个体反应的信号独立选通。Fhy3在幼苗脱黄化过程中表现出对红光的增强响应。分析两个独立的fhy3等位基因链接增强了红光对下胚轴伸长的抑制作用，并伴随着下胚轴伸长的心律失常模式。在持续的红光下，两个等位基因的中枢时钟和时钟输出基因表达的节律性也被打乱。在主观白天，Fhy3在红光脉冲下表现出反常的相位推进。从光释放实验表明，在主观一天的早期，在恒定的红光下，Fhy3的时钟被扰乱，这表明FHY3在选通红灯信号以进行时钟重置方面起着重要作用。在这些情况下，FHY3门控功能在一天的早些时候似乎对维持节律性至关重要。然而，与先前描述的拟南芥选通所有光信号的选通突变体不同，选通直接红光诱导的基因在fhy3中的表达不受影响。FHY3似乎是一个新的门控因素，特别是在白天对时钟发出红灯信号的门控方面。
Circadian gating of light signaling limits the timing of maximum responsiveness to light to specific times of day. The fhy3 ( for far- red elongated hypocotyl3) mutant of Arabidopsis thaliana is involved in independently gating signaling from a group of photoreceptors to an individual response. fhy3 shows an enhanced response to red light during seedling deetiolation. Analysis of two independent fhy3 alleles links enhanced inhibition of hypocotyl elongation in response to red light with an arrhythmic pattern of hypocotyl elongation. Both alleles also show disrupted rhythmicity of central- clock and clock- output gene expression in constant red light. fhy3 exhibits aberrant phase advances under red light pulses during the subjective day. Release- from- light experiments demonstrate clock disruption in fhy3 during the early part of the subjective day in constant red light, suggesting that FHY3 is important in gating red light signaling for clock resetting. The FHY3 gating function appears crucial in the early part of the day for the maintenance of rhythmicity under these conditions. However, unlike previously described Arabidopsis gating mutants that gate all light signaling, gating of direct red light - induced gene expression in fhy3 is unaffected. FHY3 appears to be a novel gating factor, specifically in gating red light signaling to the clock during daytime.