Modulation of copper deficiency responses by diurnal and circadian rhythms in Arabidopsis thaliana.
Modulation of copper deficiency responses by diurnal and circadian rhythms in Arabidopsis thaliana.
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DOI：
10.1093/jxb/erv474
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发表时间：
2016-01
影响因子：
6.9
通讯作者：
Peñarrubia L
中科院分区：
文献类型：
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作者：
Perea-García A;Andrés-Bordería A;Mayo de Andrés S;Sanz A;Davis AM;Davis SJ;Huijser P;Peñarrubia L
铜转运的循环表达和对铜缺乏的响应被整合到植物的光和昼夜节律振荡器信号中。缺铜状态下的铜稳态由SQUAMOSA启动子结合蛋白样7 （SPL7）转录因子调控。两个依赖spl7的缺铜标记，铜转运蛋白（COPT2）和铁超氧化物歧化酶（FSD1）的每日振荡表达，已被定量PCR和启动子：LUCIFERASE转基因植物跟踪。这两个基因都表现出昼夜节律调节。在缺铜条件下，它们的表达量在持续黑暗中急剧下降。因此，缺铜条件下黄化苗的总铜含量略有降低。在不同的光信号突变体中，SPL7及其靶点COPT2和FSD1的表达受到不同的调控。另一方面，增加的铜水平降低了核生物钟成分的振幅，如GIGANTEA （GI）。COPT1过表达系和spl7突变体中铜稳态的改变也改变了经典时钟输出的振幅，即子叶运动的昼夜节律振荡。在spl7突变体中，振荡周期保持不变。这些结果表明，铜转运在昼夜节律时钟上存在反馈，并将有节奏的铜稳态整合到植物的中央振荡器中。
Cyclic expression of copper transport and the responses to copper deficiency are integrated into the light and circadian–oscillator signalling in plants. Copper homeostasis under deficiency is regulated by the SQUAMOSA PROMOTER BINDING PROTEIN-LIKE7 (SPL7) transcription factor. The daily oscillating expression of two SPL7-dependent copper deficiency markers, COPPER TRANSPORTER (COPT2) and IRON SUPEROXIDE DISMUTASE (FSD1), has been followed by quantitative PCR and in promoter:LUCIFERASE transgenic plants. Both genes showed circadian and diurnal regulation. Under copper deficiency, their expression decreased drastically in continuous darkness. Accordingly, total copper content was slightly reduced in etiolated seedlings under copper deficiency. The expression of SPL7 and its targets COPT2 and FSD1 was differently regulated in various light signalling mutants. On the other hand, increased copper levels reduced the amplitude of nuclear circadian clock components, such as GIGANTEA (GI). The alteration of copper homeostasis in the COPT1 overexpression line and spl7 mutants also modified the amplitude of a classical clock output, namely the circadian oscillation of cotyledon movements. In the spl7 mutant, the period of the oscillation remained constant. These results suggest a feedback of copper transport on the circadian clock and the integration of rhythmic copper homeostasis into the central oscillator of plants.