Circadian rhythms confer a higher level of fitness to Arabidopsis plants
Circadian rhythms confer a higher level of fitness to Arabidopsis plants
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DOI：
10.1104/pp.004374
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发表时间：
2002-06-01
期刊：
影响因子：
7.4
通讯作者：
Tobin, EM
中科院分区：
文献类型：
--
作者：
Green, RM;Tingay, S;Tobin, EM
昼夜节律已经在整个分类谱的生物体中得到证实。鉴于它们的广泛发生，这些节奏的适应意义是有趣的。我们以前已经表明，组成型表达的CCA 1（昼夜节律相关1）基因在拟南芥植物（CCA 1-ox）的结果在昼夜节律的损失。在这里，我们证明，这些CCA 1-ox植物保留的能力，以应对昼夜变化的光。因此，转录水平的几个昼夜调节基因，以及CCA 1本身和密切相关的LHY，振荡强劲，如果CCA 1-ox植物生长在昼夜条件下。然而，与野生型植物相比，其中转录物水平在预期的暗/光转换中变化，CCA 1-ox植物已经失去了预测其环境中这种日常变化的能力。我们已经使用CCA 1-ox系来检查生物体的适应性的昼夜节律调节的损失的影响。CCA 1-ox植物开花较晚，特别是在长日照条件下，并且在非常短的日照条件下比野生型植物更不可行。此外，我们证明了另外两个昼夜节律突变体，LHY-ox和elf 3，具有低活力表型。我们的研究结果证明了拟南芥昼夜节律的适应优势。
Circadian rhythms have been demonstrated in organisms across the taxonomic spectrum. In view of their widespread occurrence, the adaptive significance of these rhythms is of interest. We have previously shown that constitutive expression of the CCA1 (CIRCADIAN CLOCK ASSOCIATED 1) gene in Arabidopsis plants (CCA1-ox) results in loss of circadian rhythmicity. Here, we demonstrate that these CCA1-ox plants retain the ability to respond to diurnal changes in light. Thus, transcript levels of several circadian-regulated genes, as well as CCA1 itself and the closely related LHY, oscillate robustly if CCA1-ox plants are grown under diurnal conditions. However, in contrast with wild-type plants in which transcript levels change in anticipation of the dark/light transitions, the CCA1-ox plants have lost the ability to anticipate this daily change in their environment. We have used CCA1-ox lines to examine the effects of loss of circadian regulation on the fitness of an organism. CCA1-ox plants flowered later, especially under long-day conditions, and were less viable under very short-day conditions than their wild-type counterparts. In addition, we demonstrate that two other circadian rhythm mutants, LHY-ox and elf3, have low-viability phenotypes. Our findings demonstrate the adaptive advantage of circadian rhythms in Arabidopsis.