Distinct regulation of CAB and PHYB gene expression by similar circadian clocks
Distinct regulation of CAB and PHYB gene expression by similar circadian clocks
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DOI：
10.1046/j.1365-313x.2002.01441.x
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发表时间：
2002-11-01
期刊：
影响因子：
7.2
通讯作者：
Millar, AJ
中科院分区：
文献类型：
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作者：
Hall, A;Kozma-Bognár, L;Millar, AJ
光敏色素 B (phyB) 是一种在光生长植物中具有活性的主要光敏色素。生物钟控制 PHYB 基因的表达。我们使用荧光素酶报告基因（LUC）来监测光感受器和时钟相关突变背景中 PHYB 的节律表达。令人惊讶的是，我们发现 PHYB 和 CAB 表达具有不同的自由运行周期，表明不同的生物钟控制着这些基因。突变的影响表明时钟具有共同的组成部分。这表明它们是相同时钟机制在不同位置的副本，很可能在不同的细胞层中。此外，我们发现 phyB 是负反馈回路所必需的，该负反馈回路强烈拮抗 PHYB 的表达。与只有一个时钟的系统相比，这种调节复杂性可能允许一个时钟控制基因的峰值表达阶段相对于其他基因或变化的环境条件发生改变。
Phytochrome B (phyB) is a major phytochrome active in light-grown plants. The circadian clock controls the expression of the PHYB gene. We have used the luciferase reporter gene (LUC) to monitor the rhythmic expression of PHYB in photoreceptor and clock-associated mutant backgrounds. Surprisingly, we found that PHYB and CAB expression have different free-running periods, indicating that separate circadian clocks control these genes. The effects of mutations show that the clocks share common components. This suggests that they are copies of the same clock mechanism in different locations, most likely in different cell layers. Furthermore, we show that phyB is required for a negative feedback loop that strongly antagonises the expression of PHYB. Compared to a system with only one clock, this regulatory complexity might allow the phase of peak expression for one clock-controlled gene to alter, relative to other genes or to changing environmental conditions.