Unanticipated regulatory roles for Arabidopsis phytochromes revealed by null mutant analysis
Unanticipated regulatory roles for Arabidopsis phytochromes revealed by null mutant analysis
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DOI：
10.1073/pnas.1221738110
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发表时间：
2013-01-22
影响因子：
11.1
通讯作者：
Lagarias, J. Clark
中科院分区：
文献类型：
--
作者：
Hu, Wei;Franklin, Keara A.;Lagarias, J. Clark
鉴于广泛的文献中的光敏色素突变体的Ler加入拟南芥，我们试图确保光敏色素无效线在相同的遗传背景进行比较研究。在这里，我们报告的分离和phyABCDE五重和phyABDE四重突变体的Ler背景下的表型特征。与早期的研究不同，这些线具有FT的功能等位基因，允许测量光周期依赖的开花行为。这两类突变体的比较研究建立，光敏色素是拟南芥的生命周期在红光下完成，尽管缺乏一个转录组学的响应，也表明phyC是非功能性的其他光敏色素的情况下。无光敏色素的植物可以在连续红光下产生光合作用所需的叶绿素，但需要提高能流率才能生存。出乎意料的是，我们的分析揭示了光依赖性和非依赖性的作用光敏色素调节拟南芥的昼夜节律钟。这些突变体从营养生长到生殖生长的快速转变，以及它们对光周期的不敏感性，建立了光敏色素的双重作用，以阻止和促进植物发育的进展，以响应占主导地位的光环境。
In view of the extensive literature on phytochrome mutants in the Ler accession of Arabidopsis, we sought to secure a phytochrome-null line in the same genetic background for comparative studies. Here we report the isolation and phenotypic characterization of phyABCDE quintuple and phyABDE quadruple mutants in the Ler background. Unlike earlier studies, these lines possess a functional allele of FT permitting measurements of photoperiod-dependent flowering behavior. Comparative studies of both classes of mutants establish that phytochromes are dispensable for completion of the Arabidopsis life cycle under red light, despite the lack of a transcriptomic response, and also indicate that phyC is nonfunctional in the absence of other phytochromes. Phytochrome-less plants can produce chlorophyll for photosynthesis under continuous red light, yet require elevated fluence rates for survival. Unexpectedly, our analyses reveal both light-dependent and -independent roles for phytochromes to regulate the Arabidopsis circadian clock. The rapid transition of these mutants from vegetative to reproductive growth, as well as their insensitivity to photoperiod, establish a dual role for phytochromes to arrest and to promote progression of plant development in response to the prevailing light environment.