Multiple phytohormones influence distinct parameters of the plant circadian clock
Multiple phytohormones influence distinct parameters of the plant circadian clock
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DOI：
10.1111/j.1365-2443.2006.01026.x
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发表时间：
2006-12-01
期刊：
影响因子：
2.1
通讯作者：
Davis, Seth J.
中科院分区：
文献类型：
--
作者：
Hanano, Shigeru;Domagalska, Malgorzata A.;Davis, Seth J.
昼夜节律系统协调内源性事件与外部信号。在哺乳动物中，生物钟反馈是一个众所周知的整合系统。在这里，我们研究了植物激素对植物的昼夜节律的影响，通过启动子：荧光素酶系统。我们报告说，许多激素控制植物昼夜节律系统的特定功能，并以不同的方式这样做。特别是，细胞分裂素延迟昼夜节律相位，生长素调节昼夜节律振幅和时钟精度，油菜素类固醇和脱落酸调节昼夜节律周期。我们证实了激素合成和感知突变体的药理学，因为在一系列与激素相关的突变体中，节律表达会发生可预测的改变。我们从遗传学角度剖析了一种将激素信号整合到生物钟中的机制，并表明，拟南芥激活的ARABIDOPSIS RESPONSE REGULATOR 4和感光细胞光敏色素B是细胞分裂素信号输入昼夜节律相位的元素。此外，我们还发现了该信号的分子表达靶点。总的来说，我们发现植物具有多个输入/输出反馈，这意味着许多激素可以对昼夜节律系统起作用，以调节生物钟以适应外部信号，从而正确地维持生物钟系统。
Circadian systems coordinate endogenous events with external signals. In mammals, hormone-clock feedbacks are a well-known integration system. Here, we investigated phytohormone effects on plant-circadian rhythms via the promoter:luciferase system. We report that many hormones control specific features of the plant-circadian system, and do so in distinct ways. In particular, cytokinins delay circadian phase, auxins regulate circadian amplitude and clock precision, and brassinosteroid and abscisic acid modulate circadian periodicity. We confirmed the pharmacology in hormone synthesis and perception mutants, as rhythmic expression is predictably altered in an array of hormone-related mutants. We genetically dissected one mechanism that integrates hormone signals into the clock, and showed that the hormone-activated ARABIDOPSIS RESPONSE REGULATOR 4 and the photoreceptor phytochrome B are elements in the input of the cytokinin signal to circadian phase. Furthermore, molecular-expression targets of this signal were found. Collectively, we found that plants have multiple input/output feedbacks, implying that many hormones can function on the circadian system to adjust the clock to external signals to properly maintain the clock system.